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Present and future large radio surveys of the extreme universe Speaker: Fender, Rob Filiation: University of Oxford Date: December, 7th 2022 Abstract: Transient radio emission is a fundamental tracer and physical probe of the most extreme and transient events in the universe. In this talk I will discuss a number of recent developments with existing radio telescopes, including i. the ThunderKAT image-plane transients programme on MeerKAT, ii. The first citizen-science project to search for commensal radio transients, iii. First radio detections of 'VHE GRBs' detected by ground-based Cherenkov arrays, iv. The possible association of a Tidal Disruption Event with an Ice Cube astrophysical neutrino. I will conclude by discussing the prospects for the next-generation of radio telescope arrays such as The SKA, and why we should consider a dedicated transient monitoring array for the southern hemisphere. |
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Moving from high to extreme precision in air shower observations: From LOFAR to SKAO Speaker: Nelles, Anna Filiation: Friedrich-Alexander-University Erlangen-Nürnberg/ Deutsches Elektronen-Synchrotron (DESY) Date: December, 1st 2022 Abstract: Cosmic rays play an interesting role in understanding the most violent objects in the universe. These charged atomic particles reach energies orders of magnitudes higher than achievable in accelerators on Earth, which points towards an origin of the most extreme objects in the universe, with strong magnetic shocks and mass transfer. However, these sources are not firmly identified. Astrophysical interpretations are currently limited by the resolution of the images that are made from the particle shower that follows each impact of cosmic rays on the Earth's atmosphere, as well as by the modelling uncertainties in the particle physics occurring in the shower development. Using LOFAR, the currently largest low-frequency telescope, we have made air shower observations with record-breaking accuracy. However, much more is still to be gained with the Square Kilometre Array Observatory (SKAO). We hope to be able to make 3-dimensional air shower images with this observatory’s extreme antenna density and thereby bring the field of air shower detection to a new regime of accuracy. This talk will report on on-going efforts within the High Energy Focus Group towards preparing for high-energy particle measurements with the SKAO. |
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A conclusive test of the cold dark matter model Speaker: Frenk, Carlos Filiation: Institute for Computational Cosmology, Durham University Date: November, 17th 2022 Abstract: TBCThe ``Lambda cold dark matter'' (LCDM) cosmological model is one of the great achievements in Physics of the past thirty years. Theoretical predictions formulated in the 1980s turned out to agree remarkably well with measurements, performed decades later, of the galaxy distribution and the temperature structure of the cosmic microwave background radiation. Yet, these successes do not inform us directly about the nature of the dark matter. This manifests itself most clearly on subgalactic scales, including the dwarf satellite galaxies of the Milky Way and especially less massive dark matter halos, too small to have made a galaxy. Apparent contradictions between the predictions from cosmological simulations and observations have led to the perception of a ``small-scale crisis'' for LCDM. I will argue that this perception stems from an innapropriate application of the simulations and that, in fact, the theory is entirely consistent with available data. I will contrast the predictions of LCDM with those of the interesting alternative of warm dark matter and show how forthcoming gravitational lensing and gamma-ray data can conclusively distinguish between the two. |
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Cherenkov Telescope Array: Status and Prospects Speaker: Cortina, Juan Filiation: CIEMAT Date: November, 10th 2022 Abstract: The Cherenkov Telescope Array (CTA) will become the reference observatory for Very High Energy (VHE) Gamma Ray Astronomy during the next decades. CTA promises a jump in sensitivity and energy coverage of one order of magnitude over the current instruments, significantly improved energy and angular resolutions and full sky coverage. Over thousand new sources will foreseeably be identified in this range for the first time. VHE gamma rays are essential to understand the so-called non-thermal universe. The fact that the northern site of CTA is located at the Roque de los Muchachos Observatory offers a special opportunity to the Spanish astrophysical community. I shall review the status of the project, deployment plans, scientific goals, and opportunities that CTA will open to our community. |
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Cosmography: the contributions of al-Andalus and the Iberian kingdoms to the Scientific Revolution Speaker: Barrado Navascués, David Filiation: CAB Date: October, 28th 2022 Abstract: "If the Almighty Lord had consulted me, before embarking on Creation, I would have recommended something simpler." This sentence, supposedly formulated by Alfonso X "the Wise", shows the complexity of cosmographic knowledge in al-Andalus and in the Christian kingdoms that received its scientific heritage. From the 10th century onwards, the Iberian Peninsula became an essential bridge for the partially lost knowledge of Greco-Roman civilization to penetrate Europe. But the contributions at different times and political powers, from the Caliphate of Cordoba to the so-called School of Translators of Toledo in Castile, passing through the Pyrenean kingdoms or Portugal, were essential to update geography and astronomy. This cosmographic knowledge, notably enriched, fed the new European universities and was essential to lay a solid foundation that would eventually lead to the Scientific Revolution of the seventeenth and eighteenth centuries. |
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The impact of JWST in AGNs Speaker: Alonso Herrero, Almudena Filiation: CAB-CSIC Date: October, 27th 2022 Abstract: The James Webb Space Telescope (NASA/ESA/CASA) was successfully launched after more than twenty years of development. It has been deploying its elements during 2022 and science operations will begin in the summer. With a collecting surface nine times larger than that of the Hubble Space Telescope, the James Webb will observe, primarily in infrared light, the faintest and most distant objects in the Universe as well as nearby galaxies in great detail, among the many astronomical objects it will target. In this lecture she will present the main features of the telescope, its scientific instruments and the Spanish participation in the project. Finally, she will describe several observational programmes to investigate the physical processes that control the evolution of nearby galaxies and their supermassive black holes, one of the great scientific challenges of our time. |
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Galactic Center: Radiation from black hole candidates and the dynamics of high velocity stars Speaker: Eckart, Andreas Filiation: University of Cologne Date: October, 24th - 28th 2022 Abstract: We summarize recent research results on the radiation mechanism of the Super Massive Black Hole (SMBH) candidate SgrA* and ask the question if there are Intermediate Mass Black Hole (IMBH) candidates in the central stellar cluster. Furthermore we give an update on the most recent high velocity stars in the central arcsecond - that are closest to SgrA*. Here we concentrate on the high velocity star cluster dynamics and on the 4711+ stars with orbital time scales down to 4 years only. |
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Studies on the origins of our solar system Speaker: Sicardy, Bruno Filiation: Paris Observatory, France Date: September, 20th 2022 Abstract: My goal in this colloquium is to apprehend globally the Solar System by describing a vast sample of small bodies, from Near Earth Asteroids to remote Trans-Neptunian Objects. This goes beyond projects that focused on certain populations only. The core of the talk is theoretical, with emphasis on inner structures and rings. Meanwhile, the stellar occultations by these objects will provide an exploratory route to characterize objects with widely different shapes and densities. The talk is centered in collisional disks and rings. Using dynamics and massive 3D collisional codes, we will describe the evolution of disks around small bodies and their confinement in narrow rings, while tracking the agglomeration of particles that lead to satellite formation in the Roche zone. This st |
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Super Massive Black Holes in dwarf galaxies Speaker: Reines, Amy Filiation: Department of Physics en Montana State University Date: September, 8th 2022 Abstract: Despite traditional thinking, an appreciable population of (relatively small) supermassive black holes may be lurking in dwarf galaxies. Before the last decade, nearly all known supermassive black holes were in the nuclei of giant galaxies and the existence of such black holes in dwarf galaxies was highly controversial. The field has now been transformed, with a growing community of researchers working on a variety of observational studies and theoretical models of dwarf galaxies hosting supermassive black holes. Work in this area not only is important for a holistic understanding of dwarf galaxy evolution and feedback, but may also just tell us how the first ‘seeds’ of supermassive black holes formed in the early Universe. In this talk, I will highlight some of my work in this field that has taken us from a few rare examples to large systematically assembled samples of dwarf galaxies hosting the smallest known supermassive black holes. |
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Stellar Magnetism and Extra-Solar Space Weather Speaker: Alvarado-Gómez , Julián Filiation: Leibnitz Institute for Astrophysics, Potsdam, Germany Date: September, 1st 2022 Abstract: The environment around the Sun and other late-type stars is controlled by magnetic fields. The coronal high-energy radiation (Extreme Ultra-Violet and X-ray photons), the structure and strength of stellar winds, as well as transients such as flares, coronal mass ejections, and energetic particle events, are some examples of this magnetic influence. Apart from their direct consequences on the star and its evolution, these phenomena will have strong effects on planetary systems via star-planet interactions and erosion of exoplanetary atmospheres. Understanding the habitability of these magnetized environments is therefore a fundamental aspect in our search for life-supporting places in the Universe. In this talk, I will summarize my research on characterizing the space weather conditions of extra-solar planets, employing advanced techniques to observe magnetic fields of stars in combination with state-of-the-art 3D numerical simulations of their surroundings. |
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Cold gas constraints via HI Intensity Mapping in the SKA era Speaker: Wolz, Laura Filiation: Jodrell-Bank Centre for Astrophysics at the University of Manchester Date: July, 21st 2022 Abstract: Intensity mapping surveys of neutral hydrogen (HI) are a new way to measure the large-scale matter distribution of our universe over a wide range of redshifts, and thus constrain cosmological parameters describing the universal expansion. The next generation of radio telescopes and interferometers - in particular the Square Kilometre Array (SKA) - are being designed and built to include optimising the detection of the HI line at low spatial resolution, allowing efficient mapping of large, previously unexplored, volumes of the universe, in both HI and continuum. The impact of instrumental systematics of radio observations on cosmological measurements can be significantly reduced by cross-correlating the HI signal with galaxy surveys. The cross-correlation also offers new ways to measure connections between HI and other properties of the optically-selected galaxy samples. I will give an overview of the status of the planned cosmological surveys to be observed with the SKA, with an emphasis on the HI intensity mapping technique and prospects of the on-going and future experiments with this technique. As well, I will showcase studies on the potential of future intensity mapping experiments in constraining HI properties, such as the global HI density, including HI scaling relations in galaxies. |
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Star-planet plasma interactions and radio emissions Speaker: Zarka, Philippe Filiation: Observatoire de Paris-Meudon Date: June, 21st 2022 Abstract: Exoplanets are expected to sustain various plasma interactions with their parent star, depending on the stellar and planetary magnetic field strengths and on the sub- or super-Alfvénic wind speed at the planet’s orbit. Three such interactions lead to electron acceleration and subsequent radio emissions in our solar system: magnetized planets hit by the super-Alfvénic solar wind, and the sub-Alfvénic interactions of the unmagnetized moon Io and and the magnetized moon Ganymede with Jupiter’s rotating magnetosphere. The resulting radio emissions are all produced by the cyclotron Maser (CM) instability. I will present the main properties of solar system CM radio emissions before summarizing the CM theory, that is at an advanced enough stage for providing a remote sensing tool of exoplanet’s magnetic field, rotation, plasma environment, orbit inclination, and interaction (type and energetics) with its parent star, provided that radio emission intensity and polarization are detected with a reasonable SNR in the time-frequency domain. Without knowing electron distributions in the sources, that can only be obtained via in-situ measurements, it is not possible to predict radio emission intensity from basic plasma physics. But I showed that solar system radio emissions follow a scaling law that relates the emitted radio power to the Poynting flux dissipated in the star-planet interaction. Extrapolated to known exoplanets, this law predicts high levels of radio emission for the ones orbiting close to their parent star, susceptible to be detected by large existing radio telescopes and arrays. I will give a brief overview of the radio detections to date, and prospects for the near future. Finally, I will propose a general framework for classifying start-planet plasma interactions, that includes the types observed in the solar system as well as yet unobserved predictions, and is perhaps even applicable to the elusive fast radio bursts. |
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Space Weather in an Era of Innovative Science Speaker: Gilbert, Holly Filiation: High Altitude Observatory, Director Date: June, 9th 2022 Abstract: The newest generation of solar observational data is allowing a pivot toward making connections in the various solar physics domains and facilitating advanced modeling for space weather conditions and impacts. We study important physical couplings in the solar atmospheric layers, as well as connections from the solar corona through the heliosphere. To advance our understanding of how solar activity and variability impact space weather conditions, improved and novel observations have recently come online from space and from the ground. Magnetism spans time and space, and we know that space weather has its origins in the Sun, but what triggers solar eruptions? The magnetized corona, which is the breeding ground of space weather, is a missing link in our understanding of the Sun-Earth chain. This talk will highlight some of the observations that address this missing link, the science they are enabling, and the implications for space weather forecasting and prediction. |
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The Antikythera Mechanism in context Speaker: Edmunds, Michael G. Filiation: Royal Astronomical Society President Date: June, 2nd 2022 Abstract: The Antikythera Mechanism. An astronomical calculator and display device found in a first century BCE shipwreck, it is mechanically more sophisticated than anything known from the subsequent millennium. I want to argue that we should be showing admiration rather than amazement, and that the Mechanism fits rather well into its historic context. But this fit has major implications for the development of humanity’s view of the Universe. |
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Empirical and physical properties of Lyman continuum emitters Speaker: Schaerer, Daniel Filiation: Université de Genève Date: May, 31st 2022 Abstract: The talk will review the state of the art of the research on the Lyman continuum emitters, a fundamental class of galaxy for our understanding of the early universe star formation. The empirical and physical properties of the Lyman continuum emitters, best kn own examples and as an entire galaxy class, will be presented and discussed. Nota: la fecha preferible es en Mayo (la dada en "Period" es indicativa); con relativa flexibilidad dependiendo de compromisos previos y docencia. |
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Charting the first billion years of our Universe with the Square Kilometre Array Speaker: Mesinger, Andrei Filiation: Scuola Normale Superiore, Pisa, Italy Date: May, 19th 2022 Abstract: The first billion years witnessed the dawn of the first galaxies, eventually culminating in the final phase change of our Universe: the Epoch of Reionization (EoR). Recent observations allowed us limited glimpses into these epochs, improving our understanding of the timing of the EoR. However, we still do not understand the first galaxies and black holes, the vast majority of which are too faint to be seen directly in the foreseeable future. Luckily, the upcoming decade is set to revolutionise studies of the Cosmic Dawn and EoR, through interferometric observations of the redshifted 21-cm line of neutral hydrogen. Specifically, the Square Kilometer Array (SKA) will map out the first billion years of our Universe: a volume corresponding to the majority of our cosmic lightcone and containing up to 10.000 times the number of modes than are in the CMB! The patterns in these 4D maps are driven by UV and X-ray radiation from the first galaxies, as well as physical cosmology. I will showcase a Bayesian, data-driven framework to understanding astrophysics and cosmology from the cosmic 21-cm signal. By forward-modeling lightcones of the first billion years, we combine existing and future observations of the cosmic dawn and the EoR. I show how the unprecedented size of the upcoming SKA dataset will allow us to recover properties of the (unseen!) first galaxies, including stellar-halo mass relations, ionising escape fraction scalings, X-ray luminosity to star formation rates, relative contributions of Population III and Population II stellar populations, and much more. |
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The cloud-scale baryon cycle across the nearby galaxy population Speaker: Mélanie, Chevance Filiation: University of Heidelberg Date: May, 12th 2022 Abstract: The cycling of matter in galaxies between molecular clouds, stars and feedback is a major driver of galaxy evolution. However, it remains a major challenge to derive a theory of how galaxies turn their gas into stars and how stellar feedback affects the subsequent star formation on the cloud scale, as a function of the galactic environment. Star formation in galaxies is expected to be highly dependent on the galactic structure and dynamics, because it results from a competition between mechanisms such as gravitational collapse, shear, spiral arm passages, cloud-cloud collisions, and feedback processes such as supernovae, stellar winds, photoionization and radiation pressure. A statistically representative sample of galaxies is therefore needed to probe the wide range of conditions under which stars form. I will present the first systematic characterisation of the evolutionary timeline between giant molecular cloud (GMC) lifecycle, star-formation and feedback in 50 star-forming disc galaxies. I will show that GMCs are short-lived (10-30 Myr) and are dispersed after about one dynamical time by stellar feedback, between 1 and 5 Myr after massive stars emerge. Despite the low coupling efficiency between early feedback mechanisms (photoionisation, stellar winds) and the surrounding gas, the parent molecular clouds are efficiently dispersed prior to supernova explosions, limiting the integrated star formation efficiencies of GMCs to 2 to 10 per cent. These findings reveal that star formation in galaxies is fast and inefficient, and is governed by cloud-scale, environmentally-dependent, dynamical processes. These measurements constitute a fundamental test for numerical sub-grid recipes of star-formation and feedback in simulations of galaxy formation and evolution. |
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Stellar clustering connecting the formation and evolution of galaxies to the formation and evolution of us Speaker: Kruijssen, Diederik Filiation: University of Heidelberg Date: May, 11th 2022 Abstract: The clustered nature of star formation leaves a long-term imprint on galaxies, stars, and planets. At young ages, stellar clustering subdivides galaxies into individual building blocks undergoing vigorous, feedback-driven life cycles that vary with the galactic environment. These units structure the interstellar medium spatially, dynamically and chemically, and collectively define how galaxies form stars. At old ages, the relics of clustered star formation persist as ancient globular clusters, which hold a wealth of information allowing us to reconstruct the assembly histories of galaxies, culminating in the reconstruction of the Milky Way’s merger tree. Towards smaller scales, stellar clustering has a measurable impact on the evolution of protoplanetary discs, the architectures of planetary systems, and the properties of planets themselves. I will discuss how this web of physical processes across a hierarchy of scales defines the cosmic ecosystem that we live in, and demonstrate that stellar clustering is at its focal point. |
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When artificial intelligence meets astronomy: celestial object census Speaker: An, Tao Filiation: Shanghai Astronomical Observatory, Chinese Academy of Sciences Date: April, 28th 2022 Abstract: Over the centuries, astronomers have continued to improve the performance of telescopes and the techniques for observing and analysing data. Nowadays, humans are building more and more advanced telescopes with larger and deeper observations, reaching terabytes and even petabytes of data. The Square Kilometre Array (SKA) radio telescope, the most ambitious project in astronomy under construction, is expected to produce more than 700 petabytes of scientific data per year since 2029. One of the main observational tasks of the super-telescope SKA is to conduct a 'celestial object census'. This is a huge work! For example, the SKA pathfinders’ survey projects are expected to detect 70 million radio galaxies. The classification and morphology of these radio sources provides key information for understanding the formation and evolution of the Universe. However, in the big data era, the challenge for astronomers worldwide has become how to access and use this vast amount of information. It is clearly impossible to identify and classify the countless number of celestial objects through visual inspection. To meet the challenge of the data deluge, astronomers seek automated and intelligent methods of data processing using supercomputers. When artificial intelligence meets astronomy new opportunities are created for scientific breakthroughs. The SKA team from Shanghai Astronomical Observatory has used artificial intelligence to develop a source finding tool and named it ‘HeTu’ (meaning Sky Map in traditional Chinese myths and legends). HeTu not only increases the depth of the deep learning network and improves accuracy, but also provides a map of the features of multi-scale objects. Experiments have shown that HeTu is able to rapidly locate, identify and classify both compact sources and extended radio sources in an automated manner, and that the results of HeTu are not dependent on the dataset used, making it more widely adaptable. |
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Constraints on the origin of free-floating planets from the mass function Speaker: Miret Roig, Nuria Filiation: University of Vienna Date: April, 21st 2022 Abstract: The stellar mass function is a fundamental parameter to constrain star formation models. Although the stellar content has been extensively studied since Salpeter's first work in 1955, the study of the planetary mass regime is only now becoming feasible. I will present a recent census of the Upper Scorpius and Ophiuchus star-forming region, where we identified between 70 and 170 free-floating planets. This is by far the largest sample of free-floating planets in a single association, and nearly doubles the number of free-floating planets known to date in the entire sky. I will show the mass function of this region (10 Msun to 4 MJup) and discuss how it can constrain the formation mechanisms that formed free-floating planets. |
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Measuring the Magnetic Fields of Exoplanets with Star-Planet Interactions Speaker: Shkolnik, Evgenya Filiation: School of Earth and Space Exploration at Arizona State University Date: April, 7th 2022 Abstract: Planets interact with their host stars through gravity, radiation and magnetic fields. For giant planets orbiting stars within ~20 stellar radii (=0.1 AU for a Sun-like star), magnetic star-planet interactions (SPI) are observable at a range of wavelengths with a variety of photometric, spectroscopic and spectropolarimetric techniques. At such close distances, planets orbit within the sub-alfvénic radius of the star, where magnetic interactions are particularly efficient, allowing for the detection and study of exoplanetary magnetic fields, thus probing their internal dynamics and atmospheric evolution. In this talk, I will provide a review (and preview) of magnetic SPI studies for hot Jupiters orbiting Sun-like stars. As we refine our observational techniques, we can extend them to lower-mass stars where the sub-alfvénic region coincides with the classical habitable zone, giving us a way with future experiments to detect the magnetic fields of potentially habitable planets. |
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Exploring the transient radio sky with the SKA and its precursors Speaker: Hessels, Jason Filiation: University of Amsterdam & ASTRON Date: February, 24th 2022 Abstract: Radio astronomical observations probe particle acceleration in some of the most extreme environments in the Universe. For example, we can trace the relativistic jets produced by accreting black holes; observe flashes from hyper-magnetised neutron stars; and study the aftermath of stars that are ripped to shreds as they pass close to super-massive black holes. These events provide critical information about the extremes of the Universe, but they are also rare and ephemeral. Thus, catching these spectacular events in the act requires radio telescopes that can monitor how the sky changes on timescales ranging from nanoseconds to years. Furthermore, the ability to monitor a large fraction of the sky, with high sensitivity, is key to discovering new phenomena. In this talk, I will describe how time-domain radio astronomy is contributing to our understanding of the Universe, e.g. through the recent discovery of fast radio bursts and other enigmatic transient radio signals. I will show how the current generation of radio telescopes have opened new vistas and set the stage for the Square Kilometre Array - an observatory whose unprecedented capabilities will surely enable the discovery of fascinating transient phenomena. |
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The Milky Way's young substellar population Speaker: Muzic, Koraljka Filiation: CENTRA - Center for Astrophysics and Gravitation, University of Lisbon, Portugal Date: February, 3rd 2022 Abstract: Young clusters and star forming regions are home to a large number of substellar objects with masses below the hydrogen-burning limit at 0.075 MSun. Most of our knowledge about their populations comes from nearby regions (d<400 pc), where we find consistent formation rates of 2-5 young brown dwarfs per 10 newborn stars. Brown dwarf theories, on the other hand, predict that high gas or stellar densities, as well as the presence of massive OB stars, may be factors that boost the incidence of newly formed brown dwarfs with respect to stars. The next frontier in substellar studies, therefore, is the exploration of massive star clusters, characterized by significantly different star-forming environments than those found in our immediate vicinity. In this talk, I will review the efforts to characterize the brown dwarfs content in various environments in the Milky Way, from the nearby star forming regions, to massive young clusters, in which we confirm the first bona fide brown dwarfs beyond 1 kpc. Additionally, I will discuss an application of the supervised machine learning techniques to characterise stellar populations of massive young clusters, and our plans to extend these studies into the substellar regime using JWST. |
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Active Galactic Nuclei as seen from the 7 X-ray eyes of eROSITA Speaker: Salvato, Mara Filiation: Max Planck Institute for Extraterrestrial Physics (MPE), Germany Date: January, 11th 2022 Abstract: Active Galactic Nuclei (AGN) are not longer considered part of a small and exotic source population but are now widely accepted to play a significant role in the evolution of galaxies through cosmic time. However, even 20 years after the realization of the close link between the galaxies and the active SMBH that they host, the various mechanisms and the interconnection are not fully clear. Two complementary approaches are followed to deepen our understanding; detailed studies of individual nearby AGN provide insight into the physics that trigger AGN activity and link it to the spatially resolved host properties, while the large samples of AGN collected from surveys, access the population properties and their impact on the evolution of their hosts with redshift and environment. Launched successfully in July 2019 on board of the Russian-German SRG mission, the eROSITA instrument and its 7 eyes have started to map the entire sky in X-rays and will continue to do so until the end of 2023. After a short description of eROSITA and its first scientific highlights, I will focus on how eROSITA is contributing to the understanding of AGN using both approaches and what this has to do with my work. |
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Unveiling the unseen magnetized universe with MeerKAT Speaker: Chibueze, James Filiation: North West University, Potchefstroom, South Africa Date: December, 9th 2021 Abstract: Galaxy clusters are known to harbour magnetic fields, the nature of which remains unresolved. Intra-cluster magnetic fields can be observed at the density contact discontinuity formed by cool and dense plasma running into hot ambient plasma, and the discontinuity exists near the second brightest galaxy, MRC0600-399, in the merging galaxy cluster Abell 3376 (redshift 0.0461). Elongated X-ray emission in the east–west direction shows a comet-like structure that reaches the mega-parsec scale . Previous radio observations detected the bent jets from MRC 0600-399, moving in same direction as the sub-cluster, against ram pressure. Here we report radio observations of MRC 0600-399 that have 3.4 and 11 times higher resolution and sensitivity, respectively, than the previous results. In contrast to typical jets, MRC 0600-399 shows a 90-degree bend at the contact discontinuity, and the collimated jets extend over 100 kiloparsecs from the point of the bend. We see diffuse, elongated emission that we name ‘double-scythe’ structures. The spectral index flattens downstream of the bend point, indicating cosmic-ray re-acceleration. High-resolution numerical simulations reveal that the ordered magnetic field along the discontinuity has an important role in the change of jet direction. The morphology of the double-scythe jets is consistent with the simulations. Our results provide insights into the effect of magnetic fields on the evolution of the member galaxies and intra-cluster medium of galaxy clusters. This talk will also include on-going collaboration between scientists at IAA and North-West University/SARAO in understanding star-planet interaction through MeerKAT observations. |
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AYA: projects and human resources in grants managed by the Spanish State Research Agency Speaker: Domínguez Aguilera, Inmaculada Filiation: UGR Date: November, 25th 2021 Abstract: This presentation will review data and results of the national calls for projects and human resources managed by the AYA team in the AEI: research projects (PGC and Challenges), acquisition of scientific-technical equipment, proof of concept projects and strategic projects; and human resources, predoctoral hiring FPI, Juan de la Cierva training, Juan de la Cierva incorporation, Ramón y Cajal and R+D+I technical staff. |
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MOSAIC: the multi-object spectrograph for ELT Speaker: Tasca, Lidia Filiation: Laboratoire d'Astrophysique de Marseille Date: November, 18th 2021 Abstract: MOSAIC will be the Multi-Object spectrograph for the ELT telescope. First light for this instrument is foreseen for 2031. MOSAIC is driven by scientific cases that include the study of the first galaxies in the Universe, the evolution of the large scale structure, resolved stellar populations beyond the Local Group, and the formation of exo-planets in different environments, among others. The instrumental concept includes visible spectrographs (covering from 0.45nm to 0.8nm), and near infrared spectrographs (covering from 0.8nmto 1.8nm), and different observing modes like HMM (high multiplex mode, in both visible and near infrared, up to ~200 targets per shot), and HDM (high definition mode, only in near infrared, up to ~10 targets per shot). This colloquim will give a detailed update of the state of the instrument, both from the technological and scientific points of view. |
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Stellar winds and their effects on exoplanets Speaker: Vidotto, Aline Filiation: School of Physics, The University of Dublin, Ireland Date: November, 11th 2021 Abstract: As the wind outflows from a star, it permeates the interplanetary medium, interacting with any planet it encounters. In this talk I will review some recent works on winds of low-mass stars and discuss the impact stellar winds can have on surrounding exoplanets. Compared to the physical interactions known to take place between the solar wind and the solar system planets, the interaction between stellar winds and exoplanets can be significantly stronger. This happens due to two main reasons: (1) the differences in the Physical properties of the host stars, such as magnetism, age and rotation, compared to the properties of our Sun; and (2) the extreme architecture of most of the known exoplanetary systems, with planets in significantly closer orbital distances, compared to solar system planets. Due to the strong nature of these interactions, they can generate observable signatures, thus providing other avenues for characterising exoplanetary systems, which would otherwise remain unknown. |
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Precision cosmology: now what? Speaker: Verde, Licia Filiation: Instituto de Ciencias del Cosmos (ICC), Universidad de Barcelona Date: September, 16th 2021 Abstract: The standard cosmological model (the LCDM model) has been established and its parameters are now measured with unprecedented precision. This model successfully describes observations from widely different epochs of the Universe, from primordial nucleosynthesis all the way to the present day. However, there is a big difference between modelling and understanding. The next decade will see the era of large surveys; a large coordinated effort of the scientific community in the field is on-going to map the cosmos producing an exponentially growing amount of data. But precision is not enough: accuracy is also crucial. The "unreasonable effectiveness" of the LCDM model offers challenges and opportunities. I will present some of the lines of enquiry explored by my group in this direction. |
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A new look at our star: the Daniel K. Inouye Solar Telescope Speaker: Cauzzi, Gianna Filiation: National Solar Observatory (Boulder, CO, USA) Date: September, 9th 2021 Abstract: The Sun represents a template for much of our understanding of the workings of a "cool" star, and its proximity allows us to observe exquisite details at its surface, with current facilities routinely reaching resolutions of few hundreds of km on the solar disk. Yet, many questions still linger, in particular concerning the actual mechanism(s) that create and maintain a hot outer atmosphere (chromosphere, transition region and corona) as well as the solar wind. We know that a major role is played by the magnetic field, that mediates the transfer to the upper atmosphere of the abundant energy provided by surface convection. However, very little is currently known about the field itself in these upper layers, owing to the difficult of measuring and interpreting the weak polarization signal created by its presence. Similarly, in the outer atmosphere we observe a dazzling variety of small and highly dynamic features that are often invoked as responsible for providing mass and energy to the corona; yet big uncertainties exist on their physical characteristics due to the small scales involved. In this talk I will focus on some of these open questions, and discuss how progress from upcoming observational facilities will improve our understanding of the magnetic and thermodynamic structure of the solar atmosphere. In particular, I will describe the possibilities provided by the Daniel K. Inouye Solar Telescope (DKIST) of the US National Science Foundation, a 4-meter facility on the island of Maui, Hawai'i, which is currently being commissioned. With its unprecedented collecting area and suite of complementary instruments, DKIST will provide the highest-resolution observations of the Sun ever achieved, as well as the sensitivity to measure the vector magnetic field in the chromosphere and in the faint corona. |
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Revealing cosmic magnetism with the Square Kilometre Array and its pathfinders Speaker: Heald, George Filiation: CSIRO Astronomy and Space Science, Australia Date: July, 22nd 2021 Abstract: Magnetism is an enigmatic but crucial element of our Universe. The structure and strength of magnetic fields are important for a full understanding of astrophysics over a tremendous range of scales: from stellar systems, to star forming regions, the properties and evolution of individual galaxies, galaxy groups and clusters, and even as a major element of the Cosmic Web. The Square Kilometre Array (SKA) promises to deliver a revolutionary view of the magnetised Universe, through the delivery of a dense all-sky grid of Faraday rotation measures (RMs) with SKA1-MID, and exquisite sensitivity to weak magnetic fields and tenuous ionized gas reservoirs with SKA1-LOW. In this talk, I will describe some of the key innovations and results that are emerging from pathfinder polarization surveys with SKA pathfinders and precursors including the Australian SKA Pathfinder (ASKAP), the Murchison Widefield Array (MWA), and the Low Frequency Array (LOFAR). In particular, I will highlight the value of polarization surveys as a novel discovery pathway for pulsars and stellar systems; explain how our first SKA-like RM Grids are crucial for uncovering extended distributions of ionised gas; and present ongoing work to constrain the detailed internal structure and evolution of magnetic fields in galaxies through the strong frequency dependence of the polarized sky. I will conclude by describing the plans that are being developed to use the SKA itself to generate a three-dimensional map of the magnetic field across the Universe. |
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TeV Halos and their connection to the Leptonic Cosmic Ray flux measured at the Earth Speaker: López Coto, Rubén Filiation: INFN, Pádova Date: July, 8th 2021 Abstract: The origin and propagation of cosmic rays (CRs) is one of the most important questions in astroparticle physics nowadays. CRs generated by known sources also serve as background to those putatively generated by more exotic phenomena such as dark matter. Apart from the known electrons of primary origin and positrons of secondary one, pulsars and sources powered by them are one of the main candidates to contribute to the total amount of CR electrons and positrons. TeV halos are sources powered by a central pulsar whose electrons and positrons have escaped from the shock region dominated by the pulsar wind and are freely propagating into the interstellar medium. They have been postulated only a couple of years ago and up to date there are only two confirmed sources. In this talk, I will give a review of the current understanding of TeV halos, the observational status and their contribution to the CR sea in the Galaxy and the local measurements at the Earth. |
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Interstellar planetesimals: 1I/'Oumuamua and 2I/Borisov Speaker: Moro-Martín, Amaya Filiation: Space Telescope Science Institute, Baltimore, Maryland, USA Date: July, 1st 2021 Abstract: Extensive surveys of extrasolar planets and of circumstellar disks around nearby stars show that planets and dust-producing planetesimals, similar to the asteroids, Kuiper belt objects and comets in our solar system, are ubiquitous around others stars. The planetesimal population of the young solar system was very numerous initially but the majority of the objects ended up ejected due to gravitational perturbations with the planets and other external perturbers. Numerical simulations indicate that many other planetary systems would have experienced a similar evolution, yielding to an interstellar space filled with ejected planetesimals. This is why, for decades, we had been puzzled that none of these interstellar planetesimals was ever detected crossing the solar system, even though it would have been easily identified as a hyperbolic comet. Then, when 1I/‘Oumuamua, the first interstellar interloper, was finally discovered, our puzzlement grew into utter bewilderment. From its detection with PanSTARRS, and taking into account the depth and duration of this survey, we can infer how many 1I/'Oumuamua-like objects are out there and this number, we will see, is at least ten times larger than what one would be expected from the ejection of planetesimals from extrasolar planetary systems, leaving unanswered the question of its origin. Furthermore, even though we would expect most of the ejected planetesimals to be icy, because the majority would originate from the outer regions of their parent systems, 1I/‘Oumuamua did not show evidence of any of the outgassing typical of solar system icy bodies, leaving unanswered the question of its composition. The discovery of 2I/Borisov, the second interstellar interloper, with an unquestionable cometary composition, has reassured us that a population of icy interstellar planetesimals exists. Similar to their crossing of our solar system, these interstellar planetesimals will also enter the environments where planet formation is taking place. |
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Organic refractory materials in space. Results from laboratory analogues Speaker: Brunetto, Rosario Filiation: Université Paris-Saclay, CNRS, Institut d'Astrophysique Spatiale, 91405 Orsay, France Date: June, 24th 2021 Abstract: Near- and mid-infrared observations have revealed the presence of organic refractory materials in the Solar System, in cometary nuclei and on the surface of centaurs, Kuiper-belt and trans-neptunian objects. In these astrophysical environments, organic materials can be formed because of the interaction of frozen volatile compounds with cosmic rays and solar particles, and favoured by thermal processing. The analysis of laboratory analogues of such materials gives information on their properties, complementary to observations. I will present new experiments to contribute to the understanding of the chemical composition of organic refractory materials in space. |
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Star-formation and accretion in galaxies from near to far: the LeMMINGs and eMERGE e-MERLIN legacy programmes Speaker: Beswick, Rob Filiation: Jodrell Bank Centre for Astrophysics, The University of Manchester Date: June, 17th 2021 Abstract: Radio emission provides a uniquely powerful and unobscured probe of the two key physical processes underway in, and powering, galaxies and their evolution: Accretion on to their central SMBH, and star-formation processes. To explore these processes, and their role in galaxy evolution, we require very high resolution (sub-arcsecond or better), sensitive imaging at radio wavelengths across large samples of galaxies in both the local and distant universe. In this seminar, I will describe the motivation and latest results from two large ‘sister’ e-MERLIN surveys (the 800-hr Legacy e-MERLIN Multi-band Imaging of Nearby Galaxies (LeMMINGs) and 1000-hr e-MERlin Galaxy Evolution (e-MERGE) surveys) which are using the e-MERLIN (the UK’s National Radio Astronomy facility, and an SKA pathfinder instrument) and NRAO’s VLA. These two projects are currently producing some of the deepest (uJy), sub-arcsecond and milliarcsecond resolution radio imaging of ‘normal’ local galaxies (LeMMINGs – surveying 280 nearby galaxies), and ‘extreme’ distant (up to z~5) galaxies (e-MERGE – 1000hr deep survey of the GOODS-N region). In each of these surveys we are able to spatially resolve, at radio wavelengths, the activity powering these galaxies. Combining this with extremely rich multi-wavelength ancillary data these surveys are separating star-formation and accretion at high redshift (allowing analysis of the co-evolution of these processes), and in local galaxies are characterising the role of low-luminosity AGN, providing a key bridge between our understanding between extragalactic AGN sources and accreting galactic blackholes. |
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Auroral Radio Emission in stars and exoplanetary systems Speaker: Trigilio, Corrado Filiation: Osservatorio Astrofisico di Catania (INAF-OACT) Date: June, 10th 2021 Abstract: In recent years, an interesting type of coherent radio emission has been detected in a wide variety of stars across the HR diagram, from hot magnetic A-B MS stars to Ultra Cool dwarfs: the Auroral Radio Emission (ARE), previously observed by spacecrafts in the magnetosphere of planets of the Solar System. Very different objects are showing the same phenomenon. What do they have in common? The first star with ARE was CU Virginis, an early type magnetic star with a tilted dipolar magnetic field, well described by the Oblique Rotator Model (ORM). Gyrosynchrotron radio emission, due to the interaction between the radiatively driven stellar wind and the magnetic field, is modulated by rotation. During observational campaigns aimed at testing a 3D model, we detected intense peaks of emission with the characteristics of Electron Cyclotron Maser (ECME), originating above the poles. They are visible as a radio lighthouse, in a pulsar-like fashion. In few words, Auroral Radio Emission. Later, ARE has been detected in other hot stars. The signature of highly beamed broad band ARE was clearly identified in many very low mass stars and brown dwarfs. The common ingredient is the presence of large-scale axisymmetric magnetic field, that allow us to use the same model developed for hot stars. We proposed that ARE in low mass star can be due to Star-Planet Interaction (SPI), as in the case of the interaction between Jupiter and its major satellites, and can be explained with the same model used for hot stars. The research for ARE in exoplanetary systems begun, and now there is a clear evidence that in the system of Proxima Cen it occurs. The model we developed for the ARE well accounts for the observations, opening new opportunity in the field of the search for life in exoplanets. |
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A Spanish in Boulder: Studying the Sun on both sides of the Atlantic (and how R&D is organized in them) Speaker: Martínez Pillet, Valentín Filiation: National Solar Observatory Date: May, 27th 2021 Abstract: The opportunity to lead the US National Solar Observatory (managed by AURA) since 2013 has allowed me to understand the differences in how R&D works on both sides of the Atlantic. These differences materialize in the various national budgeting mechanisms, the management and the mission of the R&D organizations, and the existing checks and balances at multiple levels. Although the scientific paradigms in Europe and the US are the same, the emphases display significant nuances, especially in the field of Solar Physics. While in Europe, fundamental research on the physical processes that occur in a star drives Solar Physics, in the US, the emphasis on Space Weather dominates the research priorities. I will exemplify these distinctions in the context of the multi-messenger solar physics that the combination of the experiments Solar Orbiter, Parker Solar Probe, and the NSO's 4-meter telescope, DKIST, will deploy in the next decade. |
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Regularly-spaced 8 micron cores as tracers of the earliest stages of star formation in the spiral arms of nearby galaxies Speaker: Elmegreen, Bruce Filiation: IBM Watson Research Center Date: May, 20th 2021 Abstract: Archival Spitzer Space Telescope images of most nearby spiral galaxies show prominent 8 micron emission cores when viewed with an unsharp mask technique. These cores have the IR colors of young star-forming regions, typically a million years old, behind several tens of magnitudes of optical extinction. They are usually invisible in optical images, and yet the sum of their masses divided by their likely age is comparable to the total star formation rate in the galaxy. This suggests they are the earliest stages of star formation. They are often distributed in a regular fashion along the long dust filaments and spurs of spiral arms, suggesting they form by gravitational instabilities in shock-compressed gas. |
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The HIRES/ELT consortium, instrument and science. Speaker: Marconi, Alessandro Filiation: University of Florence - INAF Date: May, 13th 2021 Abstract: (TBC) We present the results from the phase A study of ELT-HIRES, an optical-infrared, high-resolution spectrograph for ELT, which has just been completed by a consortium of 30 institutes from 12 countries forming a team of about 200 scientists and engineers. The top science cases of ELT-HIRES will be the detection of life signatures from exoplanet atmospheres, tests on the stability of Nature's fundamental couplings, the direct detection of the cosmic acceleration. However, the science requirements of these science cases enable many other groundbreaking science cases. The baseline design, which allows fulfilling the top science cases, consists in a modular fibre-fed cross-dispersed echelle spectrograph with two ultra-stable spectral arms providing a simultaneous spectral range of 0.4-1.8 μm at a spectral resolution of 100,000. The fibre-feeding allows ELT-HIRES to have several, interchangeable observing modes including an SCAO module and a small diffraction-limited IFU. |
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Nuclear star clusters Speaker: Neumayer, Nadine Filiation: Max Planck Institute for Astronomy Date: May, 6th 2021 Abstract: I review the current knowledge about nuclear star clusters (NSCs), and the spectacularly dense and massive assemblies of stars found at the centers of most galaxies. Understanding the formation, growth, and ultimate fate of NSCs is crucial for a complete picture of galaxy evolution. There is a clear transition mass in galaxies of ∼ 10^9 Msol where the characteristics of NSCs change. I argue that at lower masses, NSCs are formed primarily from globular clusters that inspiral into the center of the galaxy, while at higher masses, star formation within the nucleus forms the bulk of the NSC. I also discuss the co-existence of NSCs and central black holes, and how their growth may be linked. The extreme densities of NSCs and their interaction with massive black holes lead to a wide range of unique phenomena including tidal disruption and gravitational-wave events. Finally, we review the evidence that many NSCs end up in the halos of massive galaxies stripped of the stars that surrounded them, thus providing valuable tracers of the galaxies’ accretion histories. |
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Thematic area 9 of the CSIC’s new White Book: Understanding the basic components of the Universe, its structure and evolution. Speaker: Rainer Schödel, María José Costa Filiation: IFIC-CSIC & IAA-CSIC Date: May, 4th 2021 Abstract: CSIC is about to publish a White Book to define its scientific strategy for the coming decades. The White Book contains chapters on 14 different thematic areas. One of the main goals of this exercise is to increase collaboration between research groups and institutes of the CSIC. Particular value is set on inter- and cross-disciplinary work. Each thematic area defines a set of “challenges”, key scientific questions for the coming decade(s) in which the CSIC has or can achieve national and international leadership. The future allocation of resources in the CSIC will take these challenges into account. The challenges will be revised every four years. Here we present the ten challenges of Thematic area 9 "Understanding the basic components of the Universe, its structure and evolution.”. |
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Chaos and Instabilities in Planetary Systems Speaker: Beauge, Cristian Filiation: Observatorio de Córdoba, Argentina Date: April, 27th 2021 Abstract: The aim of this talk is to discuss recent results on the estimation of instability times through Shannon entropy and its application to planetary systems. We will analyze the complex relation between chaos and orbital instability, and how each case is able to provide important information about the dynamical evolution of the system. Finally, we will analyze how different well known planetary systems evolve. These concepts will then be applied to several well known cases, including GJ876 and our own Solar system. |
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The James Webb Space Telescope for solar systrem and exo planetary systems studies Speaker: Stansberry, John Filiation: Space Telescope Science Institute , USA Date: April, 6th 2021 Abstract: In this talk I will present the state of the art on the instrumentation of the JWST for the study on our and other solar systems. |
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Star-forming Complexes in Local Mergers and High Redshift Galaxies Speaker: Elmegreen, Debra Filiation: Vassar College, NY, USA Date: March, 30th 2021 Abstract: Disk galaxies at high redshift contain star-forming complexes, or clumps, whose masses and sizes far exceed those of clumps in local non-interacting galaxies. However, our recent Hubble Space Telescope observations reveal that local merging galaxies can form massive clumps like those at high z, with the same range of physical size, surface density, age, and star formation rate. These similarities, combined with the loss at high redshift of low surface brightness merger signatures such as tidal tails due to cosmological dimming, suggest that some clumpy high-z galaxies that appear isolated could be mergers. We find that giant clumps in local mergers contain many star clusters, with a range of ages and with standard luminosity functions. We infer from this that high redshift clumps contain (unresolved) normal bound clusters also, as a consequence of a hierarchy of star formation. |
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Searching for the formation mechanisms of brown dwarfs Speaker: de Gregorio Monsalvo, Itziar Filiation: ESO Chile Date: March, 25th 2021 Abstract: New generation of Submillimeter facilities in the North of Chile, like the APEX antenna and the Atacama Large Millimeter/submillimeter Array (ALMA), offers for the first time the possibility for studying the formation of stars, brown dwarfs, and planets with unprecedented sensitivity and angular resolution in the millimeter/submillimeter regime. The formation of Brown Dwarfs (BDs) is a debated topic of research. The most widely discussed scenarios for the formation of BDs include turbulent fragmentation, disk fragmentation and subsequent ejection, photo-evaporation of massive pre-stellar cores and ejection from multiple protostellar systems. In the last decade the presence of circumstellar disks around BDs, as well as jets, herbig haro objects, outflows, and accretion have been identified. ALMA observations helped to characterize the properties of the dust and gas disks surrounding these objects, constraining their masses and radii, and revealing the presence of grain growth to mm-grain sizes in the disk, which suggests the potential of finding rocky planets surrounding BDs. In the most recent works the presence of resolved cavities around BDs and very low mass stars has made these objects good laboratories to study disk evolution and planet formation. For more than a decade our team made an effort to shed light into the different formation mechanisms of these substellar objects using a multi-wavelength and a multi-technique approach, where ALMA has played a key role. In this talk I will provide an overview on these studies that involves observations from optical to centimeter wavelengths and the different strategies applied to search for the best pre- and proto-BDs candidates in various molecular clouds. |
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Polarimetry in the planetary sciences Speaker: Gil-Hutton, Ricardo Filiation: Universidad Nacional de San Juan y CONICET, Argentina Date: March, 18th 2021 Abstract: The past few decades have been characterized by the rapid development of astronomical polarimetry that has resulted from new polarimetric instrumentation, new techniques and new theories. Such advances have aided the exploitation of polarimetry in areas ranging from solar system bodies to exoplanets and allowed the development of completely new fields of polarimetric exploration such as cometary nuclei, transneptunian objects, protoplanetary and debris disks, and applications in astrobiology. In this talk, some important processes that produce polarization will be explained and a quick overview of the most recent advances in the area will be given. |
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Multiple stellar populations in globular and massive star clusters: Properties, origin, open questions Speaker: Charbonnel, Corinne Filiation: Université de Genève Date: March, 4th 2021 Abstract: Globular clusters (GCs) are fascinating objects nearly as old as the Universe that provide insight on a large variety of astrophysical and cosmological processes. However, their formation and their early dynamical evolution are far from being understood. In particular, the classical paradigm describing GCs as large systems of coeval stars formed out of chemically homogeneous material has been definitively swept away by recent high-precision spectroscopic and deep photometric observations. These data have provided undisputed evidence that GCs host multiple stellar populations, with very peculiar chemical properties. Evidence is also accumulating about the presence of multiple stellar populations in young massive star clusters in Local Group galaxies. In this talk, I will review the properties of these multiple populations, before presenting the different scenarios that have been proposed to explain their formation. I will focus on the (many) current theoretical issues and on the possible relationships between GCs and young massive star clusters observed in the local universe. I will conclude on open questions. |
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The exoplanet revolution Speaker: Queloz, Didier Filiation: Cavendish Laboratory, University of Cambridge Date: February, 25th 2021 Abstract: The wealth and diversity of planetary systems that have now been detected modified our perspective on planet formation as a whole and more specifically our place in the Univers. It also present an opportunity of historical perspectives and an irresistible call to look for signs of life on these new worlds as a way to explore our own origins. I will introduce the audience with the challenges and recent progresses in this new field of research and will touch upon the emergence of a new paradigm for the origins of life on Earth and its extension towards “Universal life” . |
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The Search for Advanced Extraterrestrial Civilisations via Anomalies in Astronomical Survey Data Speaker: Garrett, Mike Filiation: Jodrell Bank Center for Astrophysics, Univ. Manchester Date: February, 18th 2021 Abstract: Energy-intensive civilisations are likely to have a significant impact on both their local and extended environments – we already see evidence for this here on Earth. Advanced technical civilisations may reveal themselves to other civilisations by introducing anomalous signals into astronomical data. Artificial radio signals are perhaps the best known example but there are also many other possibilities e.g. excess infra-red emission due to waste heat losses. I will present a non-exhaustive description of some of the main anomalies or “techno-signatures” that astronomers around the world are currently seeking, with a focus on the recent work being conducted at Manchester and the Breakthrough Listen initiative (BLI). BLI has recently produced its first candidate signal – BLC1 – I will discuss this new development and the future role interferometry can play in follow-up observations and future surveys. |
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The influence of the star-forming environment on planetary systems Speaker: Parker, Richard Filiation: The University of Sheffield Date: February, 11th 2021 Abstract: Planet formation occurs at the same time as star formation, and so the environments in which stars are born are also the birthplaces of planetary systems. Star forming regions are very dense, meaning that encounters between stars and planetary systems are common. Furthermore, the intense UV radiations fields from intermediate and massive stars can truncate, or destroy protoplanetary discs. In this talk, I will describe the detrimental effects of interactions and photoevaporation on young planetary systems. I will then finish by highlighting two positive effects of the star-forming environment on planetary systems; short-lived radioisotopes and enlargement of habitable zones in binary star systems. |
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Vera C. Rubin Observatory: A Big Data Machine for the 21st Century Speaker: Rawls, Meredith Filiation: Washington University Date: January, 28th 2021 Abstract: Vera C. Rubin Observatory and its Legacy Survey of Space and Time (LSST) boasts an 8.4-m diameter mirror, a camera the size of a bus, and a 3.2-gigapixel detector. It will image the entire southern sky from Chile every few nights beginning in 2023, and enable astrophysics on all scales, from near-Earth asteroids to cosmic acceleration. With nightly data volumes around 20 TB and a final data release of 15 PB, LSST is ushering in a new paradigm for how astronomers access and use data. The software is at least as important of the science! In this talk, I will describe how data and software from Rubin Observatory will revolutionize the field and share how you can get ready for a deluge of data. |
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Osiris-Rex: results on a mission to understand planetary systems Speaker: de León, Julia Filiation: Instituto de Astrofísica de Canarias, Spain Date: January, 21st 2021 Abstract: In September 2016, the NASA OSIRIS-REx spacecraft was successfully launched from Cape Canaveral Air Force Station, in Florida. That was the beginning of an amazing journey to reach near-Earth asteroid Bennu, collect a sample of material from its surface, and bring it back to Earth in 2023. The so-called “Touch-And-Go” maneuver or TAG, took place on October 20, 2020 and the sample collector head has been safely placed into the Sample Return Capsule. Images obtained from a series of cameras on-board the spacecraft show that the collector head is holding much more than 60 g of material (the mission’s minimum requirement). Bennu is a primitive, carbon-rich asteroid, containing organic and water-bearing minerals like clays. These type of asteroids have not significantly changed since they formed nearly 4.5 billion years ago, and therefore are considered relics from the early stages of our Solar system. The OSIRIS-REx mission will bring for the first time pristine material from such early epoch, that will be analyzed in the laboratory and will help scientists to confirm if asteroids are a source of the water and organic molecules that may have made their way to Earth and other planetary bodies early in their histories. In addition, Bennu is one of the most potentially hazardous asteroid (PHA), coming close to Earth every six years. OSIRIS-REx mission spent two years orbiting and studying in detail the surface of this extremely interesting asteroid. I will go through the main findings provided by the data obtained with the instruments on-board the spacecraft, including the discovery of a rough, rocky surface, the unexpected particle ejection events, or a collection of bright, silicate-rich boulder having an exogenous origin. |
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The Blanco DECam Bulge Survey: A Panchromatic Window the Galactic Bulge Speaker: Rich, Michael Filiation: UCLA, Department of Physics and Astronomy Date: January, 14th 2021 Abstract: The development of wide field imaging cameras on large optical telescopes has opened a new opportunity to examine stellar populations over the full optical/near-IR passband. We have used the Dark Energy Camera on the Blanco 4m telescope to image 200 sq. deg of the Galactic bulge in the Rubin/LSST passbands of ugrizY. The use of the u band permits calibration of red clump star metallicities to a precision of ~0.2 dex, and the use of the u band to observe and study multiple populations in many of the globular clusters in the field of regard. We show that some claims for extremely young stellar populations in the Galactic bulge cannot be supported. We also find that the bulge divides into two abundance distributions- one close to the one-zone model of chemical evolution near the Galactic plane, and the other a more metal poor distribution, outside of 500 pc. We also find that the structure of the bulge as a function of metallicity is stratified parallel to the plane and previous claims for a spheroidal distribution for [Fe/H]<0 are not sustained. We will discuss the future science being undertaken as our sample is integrated with Gaia astrometry. I will discuss the implications for the formation history of the bulge. |
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Primordial black holes, gravitational waves and dark matter Speaker: García-Bellido, Juan Filiation: IFT (UAM-CSIC) Date: January, 12th 2021 Abstract: More than twenty years ago, we predicted that massive primordial black holes (PBH) would form via the gravitational collapse of radiation and matter associated with high peaks in the spectrum of curvature fluctuations, and that they could constitute all of the dark matter (DM) today. In 2015, we predicted the clustering and broad mass distribution of PBH, which peaks at several Msun, and whose high-mass tails could be responsible for the seeds of all galaxies. Since then, AdvLIGO/Virgo interferometers have detected gravitational waves from at least fifty merger events of very massive and spin-less black hole binaries, and we propose that they are all PBH. We have recently understood that a universal mechanism associated with rapid changes in the number of relativistic species in the early universe could have been responsible for the formation of PBH at specific scales and thus have a very concrete prediction for the mass spectrum of DM-PBH, with broad peaks at 10^{-5}, 2, 80, and 10^6 Msun. In particular, the QCD quark-hadron transition could be responsible for the efficient production of baryons over antibaryons at PBH collapse, thus explaining the presence of baryons today and the relative abundance of DM. We predict that within a few years a less than one solar mass PBH will be detected by AdvLIGO/Virgo, and that an array of GW detectors could be used to determine the mass and spin distribution of PBH dark matter with 10% accuracy. Thus, gravitational wave astronomy could be responsible for a new paradigm shift in the understanding of the nature of dark matter and galaxy formation. |
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ESO: supporting European leadership in ground-based astronomy Speaker: Barcons, Xavier Filiation: ESO Date: December, 18th 2020 Abstract: ESO is de facto the lead world-wide organisation in building and operating most powerful ground-based astronomical observatories. The success of the organisation relies on the support of its member states and the cooperation with the community, among other key factors. Over 1000 refereed papers are published every year using data from ESO facilities, with an increasingly larger fraction of these data coming from the archive. Among these scientific outcomes, there are several directly linked to Nobel Prize awards, that ESO has supported. ESO facilities are structured in terms of Programmes, currently: La Silla Paranal and ALMA (both in operation), ELT (in construction) and CTA-S (under design by CTAO). I will review the current status and future prospects of these programmes, underlining science and instrument development opportunities in the coming years as well as societal benefits of ESO's activities |
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On the formation of stellar clusters Speaker: Moraux, Estelle Filiation: Institut de Planétologie et d'Astrophysique de Grenoble Date: December, 17th 2020 Abstract: In this presentation, I will show how the analysis of the spatial distribution of young stars (YSO) and its comparison to the core population can reveal stellar formation episodes in star forming regions, and help us understand the fragmentation process. I will focus in particular on two very different regions: the relatively massive cluster NGC2264 and the Taurus association. Our recent study of the clump and YSO populations in NGC 2264 suggests a sequential star formation, starting from the northern part to the southern subregion. We propose also that the observed mass segregation in the central part is inherited from that of clumps, itself resulting from a dynamical scenario of star formation. In contrast, the Taurus association is much less dense and dynamic, which allowed us to identify pristine small scale stellar structures, called NESTs, that correspond to the preferred sites of star formation. The analysis of their properties indicates two distinct regimes which may correspond to the fragmentation of a single core or a group of cores. In addition, a further study at even smaller scale argue for a cascade fragmentation scenario. I will then finish by presenting the public sofware called S2D2 that we developed in the framework of the StarFormMapper project for the community to look for NESTs in star forming regions. |
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Stellar population gradients and kinematics of ETGs as revealed by MaNGA Speaker: Domínguez Sánchez, Helena Filiation: Instituto de Ciencias del Espacio, CSIC Date: December, 10th 2020 Abstract: In this talk I will summarise the findings presented in a series of four papers dedicated to the study of early type galaxies (ETGs) with integral field spectroscopy (IFU) from the MaNGA survey. The formation channels and mass assembly of ETGs is still a matter of debate in current galaxy evolution models. The combined analysis of galaxy kinematics and stellar population gradients (age, metallicity, alpha-enhancement, initial mass function -IMF-) is a powerful tool to disentangle between in situ star formation or merger events. We divide our sample into elliptical fast rotators (E-FR), elliptical slow rotators (E-SR) and lenticular (S0). To achieve enough signal to noise to reliably measure IMF variations, we need to stack the galaxies in bins of luminosity and central velocity dispersion. We observe significant differences between the three sub-samples — e.g., E-FR are much younger and metal rich than E-SR — , suggesting that kinematics and morphology have a strong impact on galaxy content. In addition, I will show that there are three mass-scales where scaling relations change slope and for which there is a dramatic change in the number counts and stellar population gradients of ETGs. I will also discuss the implications of IMF variations within galaxies and how this helps reconciling stellar mass with dynamical mass estimates. Finally, I will show that the thickness of the Fundamental Plane depends strongly on morphology. If the sample only includes E-SRs, then the observed scatter is significantly reduced. |
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Flaring on the Sun at all scales Speaker: Harra, Louise Filiation: PMOD/WRC Davos, ETH-Zürich, Switzerland Date: November, 19th 2020 Abstract: The Sun shows activity across a wide range of size and energy scales. We shall take a journey from the smallest scale events to the largest energy releases in the solar system. The energy release is due to the magnetic fields on the Sun and how they interact. Using EUV/UV spectroscopy different layers of the solar atmosphere can be probed in order to understand the physical processes that occur. The EUV imaging spectrometer onboard the Hinode spacecraft has been operating for 13 years with an extensive datasets. The NASA IRIS mission was launched in 2013 and provides data in the UV. In 2020 the Solar Orbiter mission has been launched providing a third spectrometer probing the solar atmosphere. We will discuss future science goals in the coming years. |
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GRAVITY+, all Sky, High Contrast, Milli-Arcsecond Optical Interferometric Imaging and Spectroscopy Speaker: Eisenhauer, Frank Filiation: MPE Date: November, 12th 2020 Abstract: GRAVITY+ will be the next generation interferometric instrument for the ESO VLT Interferometer. It will be the successor of the extremely successful GRAVITY, which has resulted in breakthrough observations of objects such as massive black holes and exoplanets. The GRAVITY+ project will upgrade GRAVITY and the VLTI in order to open up the extragalactic sky for milli-arcsecond resolution interferometric imaging, and give access to targets as faint as K = 22 mag. GRAVITY+ will measure the black hole masses of active galactic nuclei across cosmic time, and obtain high quality exoplanet spectra and orbits. Following a summer 2020 recommendation by ESO’s STC, GRAVITY+ is entering a phase A process in order to become ESO’s next VLT facility instrument. |
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The Arecibo Observatory Roadmap for the Future: science enhancement plans under UCF management. Speaker: Pinilla-Alonso, Noemi Filiation: Florida Space Institute and Arecibo Observatory, UCF. Miami, USA Date: November, 5th 2020 Abstract: The Arecibo Observatory (AO) has supported cutting-edge research in the fields of Astronomy, Planetary Science, and Space Atmospheric Science for decades. The unprecedented sensitivity of the Arecibo antenna has led to fundamental contributions in a wide variety of research programs, including the first detection of an exoplanet around pulsar (Wolszczan & Frail 1992), indirect detection of gravitational waves (GWs) that resulted in the 1993 Nobel Prize in Physics (Hulse 1994), and discovery and localization of a repeating Fast Radio Burst (Spitler et al. 2016, Marcote et al. 2016). In 2020, AO will publish its roadmap for the next decade. This document will exist as a reference, but living, document containing our vision for the future capabilities of the observatory. It will also aim to inspire the users community to open new paths for future science drivers. In this colloquium, I will discuss the science and technical roadmap in the short term and how we plan to enhance AO.s science return, with the goal of opening new and fruitful international collaborations. |
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The black hole at the Center of the Milky Way Speaker: Ghez, Andrea Filiation: UCLA, Department of Physics and Astornomy Date: October, 29th 2020 Abstract: The massive black hole at the center of the Milky Way is the nearest such object. Observations of stellar orbits have accumulated firm evidence for its nature and are being used now to test predictions of General Relativity. The observational work on Sagittarius A* by Andrea Ghez has just been awarded with the Nobel Prize for Physics 2020. |
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The star formation process on cloud-scales in nearby galaxies Speaker: Schinnerer, Eva Filiation: Max-Planck-Institut für Astronomie Date: October, 15th 2020 Abstract: Where do stars form and how is their formation regulated across galactic disks are two critical questions for our understanding of the star formation process. High angular observations of nearby galaxies allow us to sample the star formation process across entire galactic disks reaching now regularly the scales of the star-forming units, namely Giant Molecular Clouds (GMCs) and HII regions. Such data provide new insights on the molecular gas reservoir and its role in the star formation process as well as information on the importance of galactic components such as bulges, stellar bars, spiral arms and active galactic nuclei (AGN) in the conversion of cold (molecular) gas into stars. I will introduce the PHANGS (Physics at High Angular resolution in Nearby GalaxieS) survey and present a few highlights from the ongoing research of the collaborations. |
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Recent findings on nova explosions Speaker: Toalá Sanz, Jesús Alberto Filiation: Instituto de Radioastronomía y Astrofísica, IRyA-UNAM, Morelia, Mexico Date: October, 8th 2020 Abstract: Nova events are the result of the interaction of low-mass binary systems. A compact white dwarf (WD) accretes material from an old and cold companion until a thermonuclear runaway takes place on its surface. Such explosive events can be considered the scaled-down siblings of supernova (SN) explosions, but its study has many advantages over SNe, as nova events are more numerous (some systems even exhibit recurrent explosions within decades) and their evolution and expansion can be followed in human time-scales. In this talk I will review the most recent findings of our group. I will present a multi-epoch study of a sample of novae from historical archival observations in conjunction with recent ground-based images to characterize the hydrodynamic evolution of nova shells. Finally, I will address our discovery of the first magnetized jet in a classical nova using Chandra and XMM-Newton X-ray observations. |
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Following black hole evolution from z=5: mergers and outflows Speaker: Netzer, Hagai Filiation: School of Physics and Astronomy, Tel Aviv University Date: October, 1st 2020 Abstract: The growth and evolution of the most massive black holes, and their host galaxies, can be followed from z=7 and even earlier. The critical events that shape this evolution are major mergers, Eddington or super-Eddington accretion, violent star formation, and powerful outflows. I will present the results of a systematic study of 40 AGN at z~4.8 using Gemini, VLT, Herschel and ALMA. Our recent (2019) ALMA data allow a fresh look at major mergers and their association, if any, with the most violent star formation in the early universe. I will also make a connection with our recent study of ionized AGN-driven outflows at lower redshifts and try to assess their efficiency in quenching star formation. |
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J-PAS: First light results of the JPCam Speaker: Bonoli, Silvia Filiation: Donostia International Physics Center (DIPC), Spain Date: September, 17th 2020 Abstract: The Javalambre-Physics of the Acclerating Universe Asptrohysical Survey (J-PAS) have just started to scan thousands of square degrees of the northern sky with 56 narrow band filters and the JPCam instrument with the telescope 2.5m of the Javalambre Observatory. Before the JPCam started its operation, we have observed with the pathfinder camera one sq. deg on the AEGIS field (along the extended Groth Strip). This colloquium will present the results of the first light of the JPCam, and will show the potential of J-PAS through the analysis of the pathfinder mini-JPAS survey. This data were already public delivered in December 2019, and the paper with presentation of the first results (Bonoli et al 2020) submitted to A&A. |
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Massive black hole binaries in the cosmos Speaker: Volonteri, Marta Filiation: Institut d'Astrophysique de Paris Date: September, 10th 2020 Abstract: Massive black holes weighing from a few thousands to tens of billions of solar masses inhabit the centers of today's galaxies, including our own Milky Way. Massive black holes also shone as quasars in the past, with the earliest detected a mere one billion years after the Big Bang. Along cosmic time, encounters between galaxies hosting massive black holes in their centers have produced binary massive black holes that eventually coalesced by emission of gravitational waves. I will discuss the physical processes through which massive black holes pair and bind, present the analysis of cosmological simulations to investigate the properties of merging massive black holes and their host galaxies and conclude with how we can use gravitational wave observations with ESA's planned satellite LISA to constrain the evolving population of massive black holes. |
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Active Galactic Nuclei: fueling and feedback Speaker: Combes, Françoise Filiation: Observatoire de Paris Date: September, 3rd 2020 Abstract: Dynamical mechanisms are essential to exchange angular momentum in galaxies, drive the gas to the center, and fuel the central super-massive black holes. While at 100pc scale, the gas is sometimes stalled in nuclear rings, recent observations reaching 10pc scale, or 60mas with ALMA, have revealed, within the sphere of influence of the black hole, smoking gun evidence of fueling. Observations of AGN feedback will be described, together with the suspected responsible mechanisms. Molecular outflows are frequently detected in active galaxies with ALMA and NOEMA, with loading factors between 1 and 5. When driven by AGN with escape velocity, these outflows are therefore a clear way to moderate or suppress star formation. Molecular disks, or tori, are detected at 10pc-scale, kinematically decoupled from their host disk, with random orientation. They can be used to measure the black hole mass. |
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The Orion Radio All-Stars: new insights into YSO radio emission, using the VLA, VLBA, and ALMA Speaker: Forbrich, Jan Filiation: University of Hertfordshire Date: July, 30th 2020 Abstract: With significant new observing capabilities, centimeter-wavelength radio astronomy is currently in a renaissance leading up to the advent of the Square Kilometre Array (SKA), highlighting new opportunities and also technical challenges. The sensitivity upgrades of both the NRAO Very Large Array (VLA) and the Very Long Baseline Array (VLBA) have begun to provide us with a much improved perspective on stellar centimeter radio emission, particularly concerning young stellar objects (YSOs) and ultracool dwarfs. For the first time we now have systematic access to the radio time domain and new information to disentangle thermal and nonthermal emission. I will mainly present the Orion Radio All-Stars, an ongoing project targeting the Orion Nebula Cluster (ONC) with the VLA, VLBA, and ALMA. With simultaneous radio-X-ray time domain information (Chandra), this project is providing first constraints on YSO radio flares and their relation with X-ray flares, as well as improved constraints on the overall high-energy irradiation of their surroundings, including protoplanetary disks. Our astrometric follow-up of all identified VLA targets in Orion is the largest VLBA survey for YSO emission to date. Other than providing a nonthermal census, I will additionally discuss the use of the VLBA for precision stellar astrometry in the Gaia era. I will conclude with a first look at variable millimeter continuum emission in the inner ONC, targeting synchrotron flares in this new window on high-energy processes in YSOs. |
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Young Runaway Stars Speaker: Rodríguez, Luis Felipe Filiation: Instituto de Radioastronomía y Astrofísica, UNAM, México Date: February, 20th 2020 Abstract: Most stars have spatial velocities within a few km/s of the average velocity of their surroundings and can be considered to be gravitationally trapped. There are, however, a small number of stars that move at velocities of tens or even hundreds of km/s with respect to their environment and that will eventually escape from there. The archetypal runaway stars are mu Col and AE Aur that escaped in opposite directions from the vicinity of the Orion Nebula Cluster about 2.5 million years ago at velocities of order 100 km/s. Can we find “young” (i. e. recently ejected) runaway stars in regions of star formation? We will present the cases of an O6 star that was ejected about 6,000 years ago from the Welch ring of ultracompact HII regions in W51N and review the case of the BN/KL region in Orion from where six runaways ejected only 500 years ago have been detected. Finally, we will discuss the mechanisms that have been proposed to produce runaway stars. |
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Extrasolar planets: recent advances and future challenges Speaker: Cabrera, Juan Filiation: DLR Berlin Date: February, 4th 2020 Abstract: Recently a group of scientists has confirmed the presence of water in the atmosphere of a super Earth orbiting in the habitable zone of its host star. But what what does this milestone represent in the search for life outside Earth? What do we mean by habitable? What do we really know about extrasolar planets, their internal structure or origins? What is a super Earth, the most common planet category know to date for which no example is found in our solar system? How do we characterize exoplanetary atmospheres? How are these different from the planetary atmospheres in our solar system? How do we search for life? In my talk I will present an overview of recent discoveries in the field of extrasolar planet characterization with focus on their atmospheres, habitability, and the search for life. I will take the opportunity to introduce the most recent European space missions related to planet characterization: CHEOPS, PLATO, and ARIEL. |
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Extragalactic survey science in the 2020s: the role of radio continuum observations with the SKA Speaker: Sargent, Mark T. Filiation: U. of Sussex, Dept. of Physics and Astronomy, Astronomy Centre (UK) Date: January, 23rd 2020 Abstract: Extragalactic surveys in the 2020s will reveal the full diversity of the galaxy assembly process: from environment-dependent evolution to the build-up of mass inside galaxies, and with a complete accounting of all relevant processes/constituents ensured by multi-wavelength coverage. Observations at radio wavelengths carry a unique potential in that they can probe star-formation activity and cold gas content, i.e. place constraints on both galaxy growth rates and the fuel for future galaxy growth. With the construction of the Square Kilometre Array (SKA), radio astronomy will enter a new era; high-sensitivity, high-resolution and dust-unbiased radio imaging will provide a confusion-free census of star formation and black hole activity, regardless of whether these occur in dust-obscured or optically thin regions. I will review the high-priority science cases developed by the SKA Extragalactic Continuum Science Working Group and outline the challenges brought about by our still only partial understanding of some of the astrophysical mechanisms producing radio emission (e.g. the relation between star formation rate and radio continuum luminosity). Thanks to an order of magnitude increase in survey speed compared to existing radio telescopes, SKA surveys will detect millions of galaxies. I will summarize how - in addition to advancing our understanding of the drivers of the cosmic star-formation history - "commensal" survey design will ensure that information on galaxy shapes, redshifts, spatial distribution and polarization can be used for cosmological studies and to trace the evolution of magnetic fields in galaxies and the cosmic web. |
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Unveiling the nature of planetary systems Speaker: Pozuelos, Francisco J. Filiation: Space Sciences, Technologies and Astrophysics Research (STAR) Institute, Université de Liège, Liège, Belgium Date: December, 10th 2019 Abstract: The burgeoning field of exoplanets has yielded thousands of discoveries, which collectively have the potential to help us better understand our place in the Universe. Every month more and more planetary systems are being discovered, some of them in highly exotic configurations never observed previously. The combination of different techniques and studies are needed to unveil the real nature of these planetary systems. In this seminar, I will review some of the most recent photometric surveys notably dedicated to find Earth-size planets, such as TESS and SPECULOOS, and how the combination of their findings with ground-based spectroscopic surveys, such as CARMENES, can be used to discriminate between families of planets: rocky super-Earths, volatile-rich super-Earths, Neptunes etc. I will also show how dynamical simulations help to better understand the planetary architecture of each system discovered by the aforementioned methods. Indeed, as it happens with studies of our own Solar System, to yield a deeper understanding of planetary architectures, both in general and specific cases, we need to study each system as a whole by taking into consideration the star, the planets, and the minor bodies within the system (dust disks, main asteroid analogues, etc.). I will show how the combination of all these methods (photometry, spectroscopy, and dynamical simulations) is necessary to shed light onto the real nature of a given planetary system. |
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Recent advances about the exoplanetary exospheres Speaker: García Muñoz, Antonio Filiation: Technical University of Berlin and DLR Date: November, 27th - 28th 2019 Abstract: The upper atmosphere of a planet plays a key role at protecting the lower altitudes from the effects of energetic stellar EUV and soft X-ray photons and keV-energy precipitating particles. Through a variety of transport processes, the upper atmosphere also participates in the net loss of a planet’s bulk composition into space. As such, the physics and chemistry occurring in the upper atmosphere influence the evolution of a planet over its lifetime. Understanding these processes is critical to form a complete picture of planet evolution and their response to the stellar environment. Exoplanets represent a unique opportunity to advance our understanding of upper atmospheres because of the diversity of conditions they are exposed to. In this seminar, I will give an overview on recent advances in the investigation of the upper atmospheres of exoplanets, both observational and theoretical. |
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Outflows and their feedback effect in galaxies Speaker: Maiolino, Roberto Filiation: Kavli Institute for Cosmology, University of Cambridge Date: November, 14th 2019 Abstract: Galactic outflows are an essential component of galaxies' lifecycle. They regulate star formation and can even totally quench star formation in galaxies, hence transforming star forming galaxies into passive systems. I will review the properties of galactic outflows, their multi-phase nature, their driving mechanism, both in normal star forming galaxies and in galaxies hosting Active Galactic Nuclei, both in the local Universe and in primeval galaxies. I will show that the "ejective" mode is less effective than previously thought in quenching star formation in galaxies, in the sense that outflows are generally not really capable of cleaning galaxies of their gas content. However, outflows can contribute to heat their circumgalactic medium hence suppressing accretion of fresh gas, and therefore quenching galaxies as a consequence of "starvation". I will also show that, although galactic outflows are generally associated to negative feedback, they can also have a positive feedback effect, in the sense that they can also foster star formation. In particular, I will show recent evidences of star formation occurring inside galactic outflows. This phenomenon was predicted by recent models and could provide a new channel for the formation of the spheroidal component of galaxies. |
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Characterization of (exo)Planetary Atmospheres Speaker: Molaverdikhani, Karan Filiation: Heidelberg University/MPIA, Germany Date: November, 11th - 15th 2019 Abstract: Characterization of planetary atmospheres has always been a challenge. While the next generation of facilities, such as ELT, JWST, and ARIEL, will improve our understanding of planetary atmospheres, the number of well-characterized exoplanet atmospheres is expected to remain limited. Large-scale simulations assist us with this shortcoming by predicting the diversity of the planetary atmospheres, connecting the spare observational measurements, and by pointing toward the regions on the parameter space where a higher chance of the detection of planets with desired properties is expected. I will overview our current understanding of planetary atmospheres and will highlight the results of our hierarchical modelling of planetary atmospheres; including our newly proposed classification scheme for irradiated gaseous planets, the Methane Valley, and a sweet-spot to study disequilibrium chemistry by JWST. |
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Neutral and molecular gas outflows as tracers of the impact of radio jets Speaker: Morganti, Raffaella Filiation: Netherlands Institute for Radio Astronomy Date: October, 31st 2019 Abstract: Our view of the gas and its physical conditions in the central region of AGN has been enriched by the discover of fast and massive outflows of HI and molecular gas. These outflows can be driven by radiation/winds but also by the interaction of the radio plasma with the ISM. Understanding the origin and quantifying their impact requires to trace their location and derive their physical conditions (density of the gas, mass, mass outflow rate and kinetic energy of the outflow etc.). Particularly interesting has been the finding that in the first phase of their life, jet in radio galaxies can be particularly effective in driving such outflows. This crucial phase is at the heart of the idea of feedback, therefore particularly relevant for studying feedback in action. In this talk, I will present some of the results we have obtained to trace jet-driven HI and molecular gas outflows down to scales ranging from hundred to tens of pc. The impact of low-power radio jets will be discussed and the comparison with the predictions from numerical simulations will also be presented. Outflows of up to few hundred Msun/yr have been found in molecular gas using ALMA while the HI observed with VLBI is showing that the outflowing gas is clumpy as also predicted from numerical simulations. I will describe the kinematics of the gas and its conditions and the relevance they may have for feedback. |
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Molecular spectroscopy at high resolution for everyone Speaker: Martín Ruiz, Sergio Filiation: European Southern Observatory - Joint ALMA Observatory, Chile Date: October, 23rd 2019 Abstract: Molecular observations at high resolution is being revolutionized by the success of ALMA and the upcoming advent of SKA. In this talk I will explain the recent progress in the field of molecular observations in the central regions of galaxies and the big steps that we are currently making in the use and understanding of molecular tracers as a proxy to buried physical processes in active galaxies. I will show some preliminary results from the ALCHEMI ALMA Large Program aimed at imaging at unprecedented resolution and sensitivity the chemical complexity within central molecular zone of the prototypical starburst NGC 253. I will try to sneak peak its astrochemical value but also to link this study to the understanding of physical properties in distant heavily obscured galaxies as well as those of the center of our Galaxy. I will aim at showing the potential of molecular studies in a variety of astrophysical objects from local galaxies, to high-z, and/or transient energetic events like GRBs. Not only instruments like ALMA are aiming at becoming accessible to not experts in interferometry but also software tools need to play the same role. I will present the software package MADCUBA that allows to easily analyze complex molecular spectra from state of the art instruments. |
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What's is the metallicity of cool dwarf stars? Speaker: Rojas-Ayala, Barbara Filiation: Universidad Andrés Bello, Chile Date: October, 17th 2019 Abstract: Cool dwarfs are the most numerous stars in the Galaxy and they account for most of its baryonic mass. However, they are likely the least understood main sequence stars. Their complex atmospheres, due to their low temperatures and high surface gravities, have made their spectroscopic study a hard task. Until recently, their basic physical properties, such as radii and mass, were poorly constrained due to the lack of empirical data. Stellar theoretical models were also affected by this and had relied on incomplete or approximate input physics to predict their main characteristics. New methods and analyses have been created in the last decade to obtain what could be considered their least studied property: their metallicity. The abundance of metals in their photospheres can provide key information to better understand the formation and evolution of planets, stars, and our Galaxy. In this talk, I will present the latest works and advances related to the metallicities of M dwarf stars, the challenges that the cool dwarf photospheres still present to us, and discuss what else is needed to obtain precise and consistent abundances for them, as it can be achieved for FGK stars. |
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FPGAs in space: current experiences, future challenges and opportunities Speaker: Merodio Codinachs, David Filiation: European Space Agency (ESA) Date: October, 7th 2019 Abstract: FPGAs are key components in space equipment due to their versatility and performance to implement digital functions. They are embarked in satellites and used in many applications; such as observing the earth, provide telecommunications and navigation services as well as to contribute to science and explore the wider Universe. The FPGAs face very different conditions in space compared to the terrestrial applications, especially due to the radiation environment, which limits the selection of the FPGAs that can be used. This talk will provide an overview of the current use of FPGAs in ESA missions and a short introduction to the radiation effects in the FPGAs, how they are analysed, tested and mitigated. The emerging private space industry or "new space", as well as, the nanosatellites have different requirements than the class 1 programmes. The points presented are becoming even more relevant and are including new challenges. |
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Searching extended line-emission objects in wide-field survey: The IPHAS experience Speaker: Sabin, Laurence Filiation: Instituto de Astronomia, UNAM, Ensenada, Mexico Date: June, 17th - 28th 2019 Abstract: Completeness is one of the major issues affecting the study of populations of Galactic and extragalactic sources. I have been working on the detection of extended emission-line nebulae of low surface brightness in the INT Photometric Halpha Survey of the Galactic Plane using a mosaicking technique. Various new symbiotic stars, supernova remnants and planetary nebulae that had escaped earlier screening have been discovered. I will present the characteristic of IPHAS and the detection methods that were used and how this experience can be used by other imaging and photometric surveys. |
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Back to Orion Speaker: Rodrígues, Luis Felipe Filiation: Universidad Nacional Autónoma de México (UNAM) Date: June, 13th 2019 Abstract: Orion is the massive star formation region closest to the Sun and in consequence it has been studied in detail. I will present three recent results from the IRyA group on in this region. The first one is the ultraprecise determination of the distance to Orion using VLBI observations of stars with either thermal or non-thermal emission. Finally, we will focus on the extraordinary “explosion” that seems to have taken place in the Orion BN/KL region. Not only the molecular gas but also several stars are receding from a point in common with velocities of hundreds of km/s for the gas and of tens of km/s for the stars. We will present the most recent data on the proper motion of the stars and discuss the models that have been proposed to explain this phenomenon. |
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CTA: the Cherenkov Telescope Observatory for VHE Gamma Ray Astronomy Speaker: Martínez, Manel Filiation: IFAE-BIST Date: March, 28th 2019 Abstract: The Cherenkov Telescope Array (CTA), currently in construction, shall be the Cherenkov Telescope Observatory for VHE Gamma Ray Astronomy, and shall provide crucial data for the understanding of the extreme universe in the recently open multimessenger era. The goals and characteristics of the project will be reviewed, and the current status and plans presented. In addition, the crucial role of the Spanish community in this project will be highlighted. |