EAS 2020: the largest, and first ever virtual EAS meeting
Opening speech by the EAS President
Welcome from Oxford. This is a very special occasion: the first ever virtual EAS meeting. Covid-19 has provided each of us with our particular challenges but also presents us with opportunities. There is an increasing an appetite for scientific interaction: we have over 1700 registered participants from 58 countries at this meeting! During the lockdown there has been a growing awareness amongst the public of the night sky and an interest in astronomical discoveries – which we hope to enhance at this meeting. ▸ Read more
Before moving on I'd like to thank the Kuoni staff, the Leiden team and my colleagues on Council for the enormous efforts they have invested to make Virtual EAS 2020 a success. This is an ambitious aspiration — to run many plenaries and parallel sessions in virtual mode. I'm grateful to all the Chairs and the volunteers who are helping out. If there are technical hitches, please bear with us.
We hope to be back meeting face-to-face in Leiden next year and in 2022 we'll be in Valencia, Spain. For more news about your Society please attend the General Assembly at 11.00 (CEST) on Wednesday.
New Prizes: Thanks to the Fritz Zwicky Foundation we have awarded a new Prize, the Zwicky Prize, for fundamental and outstanding work in astrophysics and cosmology to Professor Martin Rees. Martin will give his talk in person (hopefully!) in Leiden next year. The other Prize winners are giving their talks as part of this meeting and they'll receive their Prizes and Medals in person next year. In order to encourage and recognise those who have overcome disadvantage to make an impact in astronomy, or those individuals or organisations that have made a contribution that goes beyond scientific research, we have instigated a new Prize. Take a look at the details on our website. Members will have an opportunity to suggest names for the new prize — I will say more later in the week.
Before I pass on to the next speaker may I wish you a stimulating, enjoyable, and most of all, safe week.
EAS 2021 in Leiden, 28 June - 2 July 2021
Proposals for Symposia, Special Sessions, and Lunch Sessions due 30 September 2020
After the transformation of the EAS 2020 Annual Meeting from an on-site meeting in Leiden to a fully virtual meeting, the EAS Council is happy to announce that the EAS 2021 Annual Meeting is again planned to take place in Leiden, the Netherlands, from 28 June to 2 July 2021. We invite proposals from colleagues interested in organising a Symposium, a Special Session, or a Lunch Session at EAS 2021. All details can be found at this page. The deadline for submitting Expressions of Interest is Wednesday 30 September 2020.
A new EAS Prize: the Jocelyn Bell Burnell Inspiration Medal
New prize named after consultation of the EAS membership
The EAS has decided earlier this year that it wishes to recognise astronomers of all career stages whose contribution to the community goes beyond scientific research, and has therefore set up a new biannual prize. In order to find a suitable name for this prize, the EAS Council has requested the EAS members to suggest names of astronomers that best fit the spirit of this new prize. Many interesting suggestions have come up, ranging from influential astronomers from ancient times to remarkable colleagues today. ▸ Read more
After careful consideration of all candidate options, the EAS Council has decided to name this prize the Jocelyn Bell Burnell Inspiration Medal, after the remarkable British astronomer Dame Jocelyn Bell Burnell. She is the discoverer of the first pulsar and has inspired (and still inspires) entire generations of astronomers. The first Jocelyn Bell Burnell Inspiration Medal will be awarded at the EAS Annual Meeting in Leiden in 2021 and in alternate years thereafter. Nominations are welcome until 31 October 2020 (see Call for nominations for EAS Prizes).
Call for nominations for EAS Prizes
Deadline 31 October 2020
EAS Council invites EAS members to nominate suitable candidates for the different EAS Prizes. The Tycho Brahe Medal is awarded annually in recognition of the development or exploitation of European instruments, or major discoveries based largely on such instruments. The MERAC Best Early Career Researcher Prizes are awarded to recognise and support young European astronomers. The Jocelyn Bell Burnell Inspiration Medal is a new prize to recognise astronomers of all career stages whose contribution to the community goes beyond scientific research. ▸ Read more
Short biographies of previous years' awardees and full details regarding the different EAS Prizes can be found on the EAS website:
New EAS Council installed at EAS General Assembly
Antoaneta Antonova and Agata Różańska officially started their term
At the EAS General Assembly, held on Wednesday 1 July 2020 during the EAS 2020 Annual Meeting, Antoaneta Antonova and Agata Różańska have officially started their term as EAS Councillors. At the same time, Council has said goodbye to Manolis Angelakis and Sofia Feltzing, who have left after many years of excellent service. The new Council consists of 10 members with a good spread in gender, geography, age and expertise. ▸ Read more
IAASARS: a new EAS Organisational Member
Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, Greece
The Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing (IAASARS) is one of the three institutes of the National Observatory of Athens (NOA). IAASARS' mission is to carry out state-of-the-art basic and applied research in ground-based and space-borne astrophysics, from distant galaxies to the solar neighbourhood, as well as near-Earth space physics, remote sensing and Earth observation. IAASARS became a new Organisational Member, Affiliate level, of the EAS in 2020. ▸ Read more
It obtained its current structure in 2012, after the merging of two institutes: the Institute of Astronomy and Astrophysics, which carried on the tradition of optical astronomy in Greece since the establishment of the Observatory of Athens in 1842, and the Institute for Space Applications and Remote Sensing, which evolved from the old Ionospheric Institute, founded in 1955. Currently (Summer 2020), the permanent staff of the institute consists of the Director, 24 researchers, 2 functional scientific personnel, 3 research support specialists and 2 technicians.
Moreover, 29 postdoctoral researchers and 27 scientists and engineers under research training (i.e. students) were on term contracts, making IAASARS the largest institute in its field in Greece.
Director of IAASARS-NOA
Director of Research, Research Center for Astronomy & Applied Mathematics, Academy of Athens, Greece
President of the Greek National Committee for Astronomy
IEEC: a new EAS Organisational Member
Institut d'Estudis Espacials de Catalunya (Institute of Space Studies of Catalonia), Spain
The Institute of Space Studies of Catalonia (IEEC) is a research institute located in the Barcelona area whose mission is to promote the development of activities related to space in Catalonia in the aspects of training, research, and innovation. The key objectives are to push the frontiers of space research from the scientific and technological domains; to become an internationally recognized centre in order to attract talent and foster collaborations both locally and worldwide; to be an efficient agent of knowledge, innovation and technology transfer in its field; and to carry out science awareness to society by communicating scientific culture. IEEE became a new Organisational Member, Affiliate level, of the EAS in 2020. ▸ Read more
IEEC is structured in four Research Units, each belonging to a university or research institution: The Institute of Cosmos Sciences (UB, University of Barcelona); the Centre of Space Studies and Research (UAB, Autonomous University of Barcelona); the Research Group in Space Sciences and Technologies (UPC, Polytechnic University of Catalonia); and the Institute of Space Sciences (CSIC, Spanish Research Council).
IAA-CSIC: a new EAS Organisational Member
Instituto de Astrofísica de Andalucía, Spain
The Instituto de Astrofísica de Andalucía (IAA) forms part of the Consejo Superior de Investigaciones Científicas (CSIC), the Spanish Research Council. IAA was established in 1975 with the aim of creating a research center of excellence in astrophysics, space science and their associated technologies. Since then, the IAA has developed into a center of reference for astrophysical research at national and international levels. In July 2018, the IAA was accredited as a "Severo Ochoa" Center of Excellence by the Spanish Ministry of Science, Universities and Research, after an evaluation by an international committee of the previous research activity and the presentation of a Strategic Plan for the period 2018-2021. IAA-CSIC became a new Organisational Member, Affiliate level, of the EAS in 2020. ▸ Read more
Both its staff (~190 members in December 2019) and the number of available facilities provide the IAA with the necessary clout to cover all major fields of astrophysics and space science, from quantum gravity over the Solar System to galaxy evolution and cosmology, and enables it to play a leading role in large international projects. Our research is based on the three pillars of modern astrophysics: Observation, instrumental development, and theoretical and numerical studies, all of which are firmly established and interconnected. The broad scope of its assets and activities is one of the main characteristics and strengths of IAA covering almost all fields of astrophysics/space science and being engaged both in remote (Earth-bound) and in-situ (space-based) observations with technological development.
IAA co-manages the Calar Alto Observatory (CAHA), the largest observatory in mainland Europe, and hosts and operates the OSN (Observatorio de Sierra Nevada), mostly dedicated to complementary long-term projects. Our Unit for Instrumental and Technical Development (UITD) provides technical support from the development of electronic components to the design of optical and NIR instruments.
Finally, our award-winning activity of our Outreach and Communication unit has a well-known reputation in the professional dissemination of astrophysics in Spain. In their high quality, diversity, and sheer number, the outreach activities carried out at the IAA are unmatched within Spain.
Linking gas and star formation throughout cosmic time
EAS 2020 Symposium 3
Symposium 3 focused on the relationship between gas content and star formation in galaxies and its evolution with cosmic time. It is very well established that gas is the fuel for star formation: its chemical and dynamical properties indeed determine how it cools, fragments and collapses into stars. Furthermore, the physical processes that regulate star formation are imprinted on the motions and abundances of the gas. To gain a unified view of the interplay between different gaseous phases and star formation, panchromatic observations from rest-frame UV to radio wavelengths are required. ▸ Read more
In the last decade, the advent of facilities like ALMA and NOEMA provided the sensitivity to probe molecular gas in star-forming galaxies across a wide redshift range, while surveys from optical and near-infrared integral field spectrographs (like MUSE, MANGA, KMOS) allowed to get a detailed view of the ionised gas properties and its interplay with star formation in both local and distant galaxies.
The goal of the Symposium was to connect the different communities focussing on the interplay between the gas content and star formation processes in galaxies at high and low redshift, from UV to radio wavelengths.
In each sub-session, the invited talks were complemented by five contributed talks (hence 20 in total), offering a broad and high-quality view of recent advances in all the covered fields. Posters were uploaded in a dedicated folder together with short video presentations and made available to all the attendees.
We managed to keep a good gender and seniority balance among both invited and contributed speakers: invited speakers were 50% female, with 3 out of 8 early career researchers, whereas for contributed talks we had 55% of women and a prevalence of graduate students and post-doctoral researchers.
Overall, the Symposium was very well attended, with around 100 people on average simultaneously connected on the platform and a peak of 198 participants. The activity on the social media platforms has also been very lively, as the dedicated slack channel counted more than 200 members. Despite the challenges posed by a fully virtual environment, the EAS organisation provided all the elements to make the Symposium a success and we would like to warmly thank them for this opportunity.
Mirko Curti (University of Cambridge, UK)
Alice Concas (University of Cambridge, UK) EAS 2020 Symposium 3 website
Stellar and gas kinematics in galaxies across cosmic time, connecting observations with theory
EAS 2020 Symposium 6
In the era of large integral field spectroscopic surveys (e.g., Atlas3D, CALIFA, MaNGA, SLUGGS, KROSS, SAMI), and ever improving galaxy formation simulations (e.g. Illustris, EAGLE, Horizon, Magneticum, NIHAO), it is key to bring together experts in all aspects of galaxy kinematics to discuss the physical processes that shape the morpho-kinematic evolution of galaxies. Symposium S6 of the virtual EAS 2020 Annual Meeting provided this opportunity. S6 was split into 6 sub-sessions covering the main aspects of stellar and gas kinematics. ▸ Read more
The first session, chaired by Camila Correa (University of Amsterdam, The Netherlands), focused on the stellar angular momentum of galaxies, used to trace galaxy morphology and to compare with cosmological simulations of galaxy formation. The session began with the invited talk of Eric Emsellem (ESO, Germany) on morpho-kinematic evolution of galaxies, and continued with contribution talks from Sarah Sweet (University of Queensland, Australia), Jesse van de Sande (University of Sydney, Australia), Juan Espejo (Swinburne University, Australia) and Claudia Lagos (University of Western Australia, Australia).
The fourth session was chaired by Claudia Lagos. Filippo Fraternali (University of Groningen, The Netherlands) started the session with a review talk on gas dynamics, and was followed by contribution talks from Lorenzo Posti (Strasbourg Observatory, France), Alice Concas (Kavli Institute for Cosmology, UK), Matilde Mingozzi (Astronomical Observatory of Padova, Italy) and Luca Cortese (University of Western Australia, Australia). The session focused on outflows and feedback efficiencies of discs and spheroids, and on the impact of environment in inducing ram-pressure stripping and morphological transformations. The session also included 3 poster presentations.
Federico Lelli (Cardiff University, UK) chaired the fifth session, which consisted of contribution talks from Carlo Cannarozzo (Universita di Bologna, Italy), Francesca Pinna (Mpia Heidelberg, Germany), Sharon Meidt (Ghent University, Belgium), Tirna Deb (University of Groningen, The Netherlands), Pavel Manera Pina (Kapteyn Institute, The Netherlands) and Sylvia Ploeckinger (Leiden University, The Netherlands). The speakers presented exciting results on the topics of merger-driven evolution of galaxies, nuclear star clusters and CO/HI gas kinematics.
The sixth and final session was chaired by Annalisa Pillepich. The invited speaker of the session was Benoit Epinat (Laboratoire d?Astrophysique de Marseille, France) who discussed various gas morpho-kinematics studies using MUSE. The speakers, Gandhali Joshi (Mpia Heidelberg, Germany), Sara Cazzoli (IAA-CSIC, Spain), Valentina Abril Melgarejo (Laboratoire d?Astrophysique de Marseille, France) and Wilfried Mercier (Irap, France) gave contribution talks. The session focused on galaxy evolution in dense environments and it concluded with 5 poster presentations.
The total virtual attendance of the symposium vastly exceeded the initially foreseen participation. We are particularly grateful to all our speakers, who gave excellent talks, making the Symposium S6 a success. We also warmly thank all the organisers of the EAS 2020 virtual platform, without their effort the Symposium would not have been possible.
Camila Correa (University of Amsterdam, The Netherlands)
Claudia Lagos (International Centre for Radio Astronomy Research, Australia) EAS 2020 Symposium 6 website
The Magellanic Clouds in the 2020s: a spectroscopic perspective
EAS 2020 Symposium 7
The Magellanic System has long been instrumental in driving our understanding across many fields of astrophysics, ranging from its importance in a cosmological context and the determination of the Hubble constant to the study of astrophysical phenomena under different environmental conditions. Deep, wide-field panchromatic photometric surveys (including the VMC, SMASH and DES) have measured the distribution, ages and masses of the faintest stars, uncovering unmistakable signs of interactions between the Magellanic Clouds as well as identifying a host of ultra-faint dwarf satellite galaxies associated with the System. ▸ Read more
Whilst these data are still being exploited to explain the vast amounts of substructure, there is currently a dearth of large-scale spectroscopic follow-up. With the advent of instruments such as 4MOST and MOONS, as well as continuing contributions from existing projects (such as APOGEE-S, MAGIC and MagES), this relative lack of spectroscopic data will be addressed, thereby completing our dynamical and chemical views of the Magellanic System.
This two-day Symposium brought together observers and theorists within the community to coordinate our efforts and discuss how these ancillary data will further transform our understanding of this unique system. Within our Symposium, we had 10 invited talks and 14 contributed talks. The invited talks were given by researchers at different stages of their career, from starting postdoc through to professor. We also included three short poster sessions where we offered the possibility to briefly present posters. Among all speakers of our Symposium, 42 per cent were female. The Symposium was well attended with up to 80 participants at each session.
Laura Cullinane started the third session by introducing the Magellanic Edges Survey which maps the outer regions of the Clouds. Denis Erkal presented various techniques to measure the mass of the LMC, showing that it is larger than previously thought. Pol Massana talked about his work on the star formation history of the SMC using data from the SMASH survey. Michele De Leo gave the last talk of the day, presenting his studies of the stellar kinematics of the SMC.
The second day of the Symposium started with the talk by Douglas Boubert who presented a search for hypervelocity stars that might have been ejected from the LMC. Laura Inno gave a review of the three-dimensional structure of the Magellanic Clouds traced by Cepheids. Bertrand Lemasle presented a new method to derive atmospheric parameters of Cepheids and future spectroscopic observations with 4MOST. Anna Jacyszyn-Dobrzeniecka gave the final talk of the session, presenting her studies of Cepheids within the Magellanic Bridge using data from the OGLE survey and follow-up spectroscopic observations.
Sebastian Kamann started the fifth session of the Symposium with a comprehensive overview of the studies of star clusters within the Magellanic Clouds. Joachim Bestenlehner gave a review talk on massive stars in the Magellanic Clouds focussing on results from recent spectroscopic surveys. Sarah Brands presented her work on modelling the wind properties of massive stars in the R136 cluster. Julia Bodensteiner talked about her study of the binary fraction and physical properties of the massive stellar population within the young cluster NGC 330 using MUSE data.
The last session of the Symposium was opened by Guillaume Guiglion who introduced a novel method based on machine learning to derive physical properties and chemical abundances from stellar spectra. Maria-Rosa Cioni presented the forthcoming One Thousand and One Magellanic Fields survey on 4MOST which aims to measure the kinematics and chemical abundances of various stellar populations within the Magellanic Clouds. Alessio Mucciarelli introduced MOONS, the new multi-object spectrograph at the VLT and its capabilities to study the Magellanic Clouds. The last speaker of the Symposium was Eric Pellegrini who introduced SDSS-V's Local Volume Mapper which will provide a full optical spectroscopic image of the Magellanic Clouds at 10 pc resolution.
We thank all the speakers and the numerous attendees for making Symposium 7 a successful one. We are particularly grateful to the organisers for setting up the platform as well as the tools for the virtual meeting and the support during the sessions.
Cameron Bell (AIP Potsdam, Germany)
Florian Niederhofer (AIP Potsdam, Germany)
Dalal El Youssoufi (AIP Potsdam, Germany)
Maria-Rosa Cioni (AIP Potsdam, Germany) EAS 2020 Symposium 7 website
Common-envelope systems: progenitors, mergers and survivors
EAS 2020 Symposium 8
The study of the common-envelope (CE) phase has raised an increasing interest over the years in both observational and theoretical fields. Nearly 400 papers with the phrase "common envelope" in the abstract are listed in the ADS for 2016-2019, but no major meeting on the topic has been organized in the recent years in Europe. The goal of the S8 session was to discuss the latest advances in the studies of CE evolution on both theoretical and observational fronts. ▸ Read more
Post CE systems are well known in population synthesis, both among low- and high-mass stars, but constraining the physics of the common envelope ejection from population studies is a very difficult task. Incoming observations, such as those from the Zwicky Transient Factory, deliver new data on the different post-CE populations in the Galaxy. Of great interest are currently massive binary systems that result in black hole (BH-BH) pairs and neutron star pairs (NS-NS) whose mergers are observed by gravitational-wave detectors. It is of prime interest to establish what were their progenitors and arguments for cool supergiants were discussed. It was also proposed that some of low-mass post-CE systems, such as envelope-stripped helium stars, can be observable by the next-generation gravitational-wave detectors.
Aside to the massive gravitational-wave sources, other observational aspects of the CE evolution were discussed. A link between some (pre-)planetary nebulae (PPNe & PNe) and CE in AGB and RGB systems has been reinforced by recent observations at optical and submillimeter wavelengths. They allowed detailed studies of the spatio-kinematic structure of the nebulae (atomic and molecular), constrained their masses and chemical compositions (elemental and isotopic), and revealed properties of the central stars (foremost, binarity). There is a building evidence for mass transfer before and after the CE phase. Even more recent is the realization that outbursts of Galactic and extragalactic transients are most likely directly related to the CE phase, including stellar mergers that can be observed in real time. These are known as (luminous) red novae or intermediate-luminosity optical transients (ILOTs). Some of them, called SPIRITS, are so heavily dust-enshrouded that are practically only observable at infrared wavelengths. These past or ongoing mergers are mainly observed in systems of low-mass stars but their characteristics is similar to merger events in more massive systems, like the one that has been hypothetized to explain the Great Eruption of eta Car. The identification of the red transients as manifestations of stellar collisions brought fresh interests in studying cataclysmic outcomes of the CE evolution. The search for systems undergoing a red nova phenomenon and their field progenitors continues. On the high-mass side, the example of V766 Cen shows that we can resolve high-mass binary systems in contact just before or during the common envelope phase.
Extremes in accretion onto strongly magnetised neutron stars: observations vs. theory
EAS 2020 Symposium 9
Neutron stars (NSs) are known as natural laboratories to study physics under extreme conditions of high density, strong magnetic and gravitational fields. The strength of the magnetic field at the NS surface can exceed the maximal magnetic field strength achievable in labs by a few million. A number of strongly magnetized NSs belong to close binary systems, and their luminosity in X-rays is powered by accretion when a NS catches and absorbs material from its companion in a binary. Extreme accretion regimes emphasize specific features of the interaction between radiation and matter, providing an opportunity to use the observational data in tests of physics under extreme conditions. ▸ Read more
Recent years have brought high-quality data from X-ray observatories (NuSTAR, XMM Newton, Chandra, Swift) and quite a few important discoveries. On the one hand, it has been shown that NSs in close binary systems can be enormously bright, manifesting themselves as pulsating Ultra-Luminous X-ray Sources (ULXs). On the other hand, it is finally becoming possible to detect accreting NS at very low mass accretion rates, where some sources have already shown surprising spectral and timing behaviour. Symposium 9 on extremes in accretion onto strongly magnetised neutron stars was a great opportunity to bring together experts (both observers and theoreticians) who focus their research on different aspects of extreme accretion onto strongly magnetised NSs.
We had six sessions, and different sessions were focused on different aspects of extreme accretion:
We see that the observational results nowadays are standing far in front of coherent theoretical models, which face complications in the theoretical description of radiation and matter interaction under conditions of a strong magnetic field. However, there are a few groups that attack the problem, and their results give hope for further progress in the coming years.
In the next few years, a new revolution is expected in observational X-ray astrophysics with the launch of the first X-ray polarimeters (IXPE, eXTP). Since the essential processes in a strong magnetic field are dependent on polarisation, accreting highly magnetized NSs are prime targets for the upcoming X-ray polarimeters. Another revolution is expected with the launch of XRISM X-ray micro-calorimeter, which will improve our capability of detecting winds and cyclotron lines in ULXs and NSs significantly.
We are particularly grateful to all our speakers and the numerous attendees, contributing to making Symposium 9 a success. We also thank all the EAS organization, and all people worked on the conference's interactive platform and helped us at every step.
Nathalie Degenaar (Uni. of Amsterdam, The Netherlands)
Paolo Esposito (IUSS, Pavia, Italy)
Felix Fuerst (ESA/ESAC, Spain)
Filippos Koliopanos (IRAP, France)
Matt Middleton (Uni. of Southampton, UK)
Alexander Mushtukov, chair (Leiden Uni., The Netherlands)
Ciro Pinto (ESA, The Netherlands)
Marina Romanova (Cornell Uni., USA)
Sergey Tsygankov (Uni. of Turku, Finland)
Natalie Webb (IRAP, France)
Gaia: the (two) billion star galaxy census: the promise of (E)DR3 and ground-based synergies
EAS 2020 Symposium 10
The GREAT (Gaia Research for European Astronomy Training) initiative is a pan-European research network involving over 500 researchers in 20+ countries with a common interest in aiming to maximise the science potential of Gaia. The 13th GREAT network annual plenary meeting was held during the EAS 2020, constituted as Symposium 10. It was organised in six sessions, with 36 presentations, over the days 29-30 June 2020. In addition an associated lunch session (LS7) was organized in which the proposal for GaiaNIR was presented followed by poster short presentations. The symposium was attended by over 100 people for each session with a peak of almost 200 attendees for the session on Gaia EDR3. ▸ Read more
The first session in S10 was dedicated to highlights from the science done
with Gaia DR2. May Gade Pedersen kicked off the symposium with a discussion on how Gaia and Kepler can be combined to learn about the internal rotation
profiles of B-stars, through asteroseismic modelling. This was followed by a
presentation by Giulia de Somma on the application of the first theoretical
period-age-colour relation for Cepheids in the Gaia photometric bands,
allowing to estimate ages for Cepheids. Moving to the other side of HR diagram
Nicholas Chornay presented his work to carefully match the Gaia DR2 catalogue
to central stars of known planetary nebulae, thus unlocking the power of Gaia
to study PNe. Stefan Krauss then discussed the plans for the VLTI instrument
BIFROST which will be used to complement the Gaia binary survey (planned for
Gaia DR3), so that precise dynamical masses, ages, and spin-orbit alignments
can be derived for a large sample of binaries. The next two talks by Ana
Queiroz and Eloisa Poggio discussed the bar and bulge as seen by Gaia DR2 and
Apogee, and the evidence for a dynamically evolving Galactic warp from Gaia
DR2. Both presentations were the topics of recent press releases, to be found here and here.
The fourth session was dedicated to synergies between Gaia and ground-based surveys and started with an overview, presented by Joss Bland-Hawthorn, of the results obtained by the GALAH survey, showing how the powerful combination of this spectroscopic survey and Gaia DR2 can be used to dissect the stellar disc's phase space in abundance, action, age, and location. Michael Hayden followed with a presentation of the chemo-dynamics of the solar neighbourhood as seen by GALAH+Gaia. Neige Frankel gave a beautiful exposition of the ways in which stellar disks evolve in the presence of spiral arms, radial migration, and heating and how this can be measure with APOGEE+Gaia. Matthias Steinmetz presented a preview of the final RAVE data release which will be a very nice taster for data forthcoming from the Gaia Radial Velocity Spectrograph in future releases. Maria Tsantaki presented the effort to combine a number of the existing spectroscopic surveys, by matching them to the Gaia DR2 source list and then carefully homogenizing the parameters derived from the spectra, thus enabling a homogeneous view on the different parts of the Galaxy covered by the surveys. The session was closed by the presentation of the PASIPHAE survey by Konstantinos Tassis, which aims at 3D magnetic tomography of the Galaxy, through the measurement of optical polarization of stars. The aim is to better remove the dust foreground from CMB maps. The Gaia parallaxes of course play a crucial role in the 3D aspect.
The topic of session 5 was open clusters and star formation. Alfred
Castro-Ginard showed how modern data mining techniques can be put to good use
to find new open clusters in the Gaia DR2 data, resulting in over 580 new
clusters discovered in his most recent work. Laia Casamiquela showed how open
clusters, when studied in detail with spectroscopy, can be used as chemical
clocks in the study of the chemical evolution of the Milky Way. Stefan
Meingast turned the attention toward the young clusters near the sun, showing
newly discovered extended structures around many of them, which are thought to
arise from a combination the birth condition of the clusters and their
subsequent dynamical evolution. Josefa Grossschedl used the combination of
Gaia DR2, APOGEE, and CO gas measurements to derive the 3D shape of the Orion
A, cloud and show that it was shaped by feedback from the winds and SNe of
massive stars. A very complementary study presented by Sara Rezaei Kh. showed
how the combination of Gaia DR2, 2MASS, and WISE can be used to produce 3D
dust maps of the Orion region. The results are consistent with the shaping of
the detected dust clouds by a population of stars in the foreground of Orion
A. The session was close by Gábor Marton who presented a machine learning
method to discover young stellar objects in the Gaia DR2 + ALLWISE catalogue.
The Local Group in context: galaxies in the Local Volume as a testbed of cosmology
EAS 2020 Symposium 11
Faint dwarf galaxies have traditionally been discovered and studied in our immediate cosmic neighborhood, the Local Group of Galaxies, as satellites of the Milky Way and Andromeda. Simulations based on the ΛCDM model of cosmology have struggled to reproduce several aspects of these nearby satellite galaxy systems, resulting in a number of "small-scale challenges". Since their identification, substantial theoretical progress has been made in addressing many of these challenges, including improved modelling of baryonic effects in hydrodynamical simulations, as well as a flurry of other proposed solutions within and outside of the ΛCDM paradigm. However, these are often implicitly tailored to the Local Group due to the preponderance of data from our immediate neighborhood. ▸ Read more
Meanwhile, multiple surveys (e.g. Saga, PISCeS, Dragonfly, DGSAT) are actively studying galaxy systems beyond the Local Group. These efforts and upcoming advances in observational capabilities (e.g. ELTs, LSST, JWST, Euclid) allow comparisons with model expectations for a growing sample of galaxies and galaxy groups in the larger-scale Local Volume. This is an opportunity to determine how peculiar the Local Group is, to investigate which small-scale challenges are present on a larger scale, and thus to expand the scope of near-field cosmology. Proposed solutions and alternatives to ΛCDM (e.g. warm and self-interacting dark matter, or more radical approaches such as MOND) can now be tested by comparing them to the observed galaxies and satellite systems in the Local Volume.
Our symposium brought together observers and theorists, both those working on the Local Group and those studying the larger-scale Local Volume. It was split into six sessions, with one invited talk each, a total of 24 contributed talks, and 10 posters. Our virtual sessions typically had 60-80 participants, ample questions and a lively discussion on the associated Slack channel. There was general agreement that the virtual format worked well and, with some appropriate scheduling, it allowed our speakers to participate not only in Europe, but all over the world, ranging from Australia in the East to Hawaii in the West.
Quenching cluster galaxies in the cosmic middle ages
EAS 2020 Symposium 14
Galaxy clusters and groups represent an extreme environment for galaxy formation and evolution. In the local Universe, this leads to a wide variety of differences in galaxy properties such as colours, star formation rates, gas content, and morphologies between cluster and field galaxies. These differences are, however, much smaller in the high-redshift Universe (z ≳ 1.5), implying that the effect of the cluster environment first sets in at intermediate redshift (0.3 ≲ z ≲ 1.5). This Symposium brought together both observational and theoretical astronomers with an interest in this intermediate phase of galaxy evolution, giving the communities an opportunity to update each other on recent progress, identify the shortcomings in current models, and discuss which future observations and simulations will be most beneficial to making progress in this field. ▸ Read more
The programme was split over four blocks, and featured four invited and 14 contributed talks (with exactly half in each category given by male and female speakers). These addressed four broad sub-topics related to our Symposium theme:
Each session was well-attended by 50-100 participants, reflecting the significant place of this topic at the intersection of galaxy formation, large-scale structure, and cosmology.
Yannick Bahé (Leiden Observatory)
Remco van der Burg (European Southern Observatory) EAS 2020 Symposium 14 website
The circumgalactic medium
EAS 2020 Symposium 15
Symposium 15 focused on the circumgalactic medium (CGM) and aimed at gathering together observers and theorists to discuss the latest works on the study of this medium which is at the interface between galaxies and the large-scale structures of the Universe at different redshifts. Within the context of substantial recent progress in improving numerical simulations and theoretical models, successful large observational surveys, and forthcoming large facilities, this is an extremely timely topic. ▸ Read more
The four session blocks were organized around three main topics. Each of these topic started by a review talk given by an invited speaker. Lutz Wisotzki (Leibniz-Institut fur Astrophysik Potsdam) started the session "Mapping of the CGM"
by presenting the recent observations of the CGM in emission and highlighting the high complementary of the results obtained with absorption
lines studies. The second topic of the Symposium "The flows around galaxies" was introduced by Michele Fumagalli (Durham University)
who reviewed recent and ongoing efforts to characterize the impact of gas flows on the evolution of galaxies using observations and simulations.
Finally, Celine Peroux (ESO) started the last session of the Symposium by telling us about the baryon content and metal enrichment through
the various phases of the CGM.
XMM-Newton: current scientific highlights and future prospects
EAS 2020 Symposium 16
The 20 years of XMM-Newton observations have dramatically changed and increased our understanding of all astronomical X-ray emitting sources, from the solar system objects in our neighborhood to distant AGN and clusters of galaxies. The symposium celebrates XMM-Newton's 20th anniversary by highlighting its current scientific achievements. In addition, XMM-Newton is expected to continue to provide such observations for the coming decade as one of the leading X-ray facilities. In the early 2030s XMM-Newton will be replaced by ESA's next generation of large X-ray observatory, Athena. Thus, permanent access to the X-ray sky will be provided for the astrophysical community by ESA. ▸ Read more
The symposium was organized in four sessions, which were led by four invited highlight talks.
Natalie Webb chaired the second session which discussed various aspects of X-ray binaries: the accretion and outflows in low mass X-ray binaries and transitional milli-second pulsars, the stellar wind and accretion structure in high mass X-ray binaries with emphasis on Vela X-1, the X-ray emission of middle-aged pulsars, the spin evolution and orbital ephemeris of the ultra-luminous X-ray source NGC 7793 P13, and the accretion in supergigant fast X-ray transients with XMM-Newton fill-in observations (N. Degenaar; V. Grinberg; B. Posselt; F. Fuerst; C. Ferrigno).
Rudy Wijnands chaired the third session which discussed active galactic nuclei and clusters of galaxies: the discovery of quasi-periodic eruption in the nuclei of GSN 069 and RX J1301.9+2747, the multi-wavelength, long-term evolution of the tidal disruption event AT 2018fyk, the X-ray ultra-fast outflow from the highly accreting supermassive black hole of PG 1448+273, the first results form XMM-Newton follow-up of ~400 galaxy clusters allowing to probe the cosmic isotropy, and the high-ionisation line of the hot interstellar medium (M. Giustini; T. Wevers; M. Laurenti; T. Reiprich; D. Rogantini).
Norbert Schartel chaired the fourth and last session in which first results of the XMM-Newton's multi-year heritage-program on LSST Deep-Drilling Fields was presented, followed by a presentation of Europe's next large X-ray facility, Athena, the development of the X-ray mirrors for Athena, and the prospects of the new X-ray missions IXPE and eXTP (N. Brandt; D. Barret; L Keek; R. Mikusincova; J. In't Zand/M. Hernanz).
Maria Diaz Trigo (ESO, Munich, Germany)
Norbert Schartel (ESA, Madrid, Spain)
Natalie Webb (Institut de Recherche en Astrophysique et Planétologie, Toulouse, France)
Rudy Wijnands (University of Amsterdam, Amsterdam, The Netherlands) EAS 2020 Symposium 16 website
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