European Astronomical Society
e-Newsletter  1
October 2016

At the same time of this transition, there was also a change in editorship. Prof. Vassilis Charmandaris, currently Director of the IAASARS of the National Observatory of Athens, has been the EAS Newsletter editor for ten years, and he has fulfilled his duty with passion and expertise. In January 2016 I took over this responsibility. My first challenge was to lead the transition from the paper to the electronic newsletter. I am very thankful to Prof. Charmandaris for all the background information, help and suggestions provided to make this transition as smooth as possible. I consider it an honour that Council has given me the possibility to continue the work that Prof. Charmandaris has done for all these years, and I hope to be a worthy successor. I also specifically want to thank Dr. Marc Türler from the University of Geneva for all the technical assistance without which this new format would not have been possible.

This first issue of the e-Newsletter is largely dominated by the very successful EWASS meeting held in Athens past July. You can find the opening message from the President, and reports on most of the symposia and special sessions that were organised during the meeting. But there is more to be found in this issue: it contains news on the EAS Prizes awareded during EWASS 2016, on EWASS in coming years, on the EAS Facebook page, etc. Scroll up and down, and find out.

We hope you will appreciate this new medium, which will appear four times per year. And I also count on you, astronomers throughout Europe and beyond, to provide feedback and to contribute content for the following issues of this new medium (email me at maarten.baes @ ugent.be).

Maarten Baes (Universiteit Gent)
EAS e-Newsletter editor

The preparation of EWASS17 also took some effort. Work is now well underway. The membership of the SOC and EHC are established. The call for symposia and special session has been issued. Finally regarding the EWASS development, we did think of the longer term, organised the selection of the 2018 EWASS and established the procedures for the selection of future EWASS meetings. Pending some last discussions, we will announce date and place of EWASS 2018 in late September or beginning of October. All the efforts invested during the last years in the development of the EWASS meetings led to EWASS meetings becoming now the important gathering of the European astronomical community. With these meetings, the European astronomical community has a powerful tool to contribute to building its future.

We also did progress on the establishment of a presence of the European astronomical community in Brussels. The strategy team leading this activity met in order to have a first cut at the activities that the person representing the EAS should develop. This was done in collaboration with a candidate, who, however, decided afterwards to give a new term to her carrier. We are therefore in the process of finding another candidate and are hopeful that we will be able to concretely start this activity in the coming few months.

Council had a discussion on the steps to let the EAS publication series evolve. Corinne Charbonnel had taken over from Jean-Paul Zahn some time ago. This was an opportunity to look at the direction this effort ought to take. After some thinking, council decided to interrupt the series. It was found that the only meaningful publication would be school proceedings, but then even those are moderately useful in terms of publications, major review journals being a preferred path for such proceedings. Related to this question is that of the whole communication of the EAS, a question that is on the table with the arrival of Maarten Baes as new newsletter editor.

A new set of elections took place this spring. We have the pleasure of welcoming Sofia Feltzing, Lex Kaper and Georges Meylan as new councilors, and Maarten Baes replaces Vassilis Charmandaris as Newsletter editor. Welcoming new members also means saying good bye to others. Eline Tolstoi and Mike Bode leave us. I am very thankful for their time, effort and support of the EAS activities during their mandate in Council. I am also very thankful for the work and energy that Vassilis invested in the Newsletter, an important vehicle of communication within our society.

As you well have seen the present election procedure functions by default. It is only if members do not agree with the slate proposed by council and produce an independent proposal that members are called to express their opinion. Council thinks that this could now be improved upon to give members a more active part in selecting council. Council will therefore propose next year an amendment to the constitution or by-laws to implement this.

This leads me to a deep worry. The EAS membership is only a poor representation of the European astronomical community. Our colleagues often think that their membership is not important and that the few who spend time and effort for the benefit of all can manage without additional support. This is not so. The society considerably increased its level of activity at the service of European astronomers, EWASS is an example of this evolution. The strength of the voice of the astronomers on the political scene, the presence of our community in discussions regarding the future facilities and the evolution of our way of working now depend on the presence of astronomers within the society. Efforts must be made by all members to encourage their colleagues to join so that the membership gives a faithful representation of the whole community.

Finally, Council decided to devolve financial means to the activities of its working groups. This should help to give professional support to make the best of the efforts of our working groups. On the front of the working groups, however, we did not progress as much as we wanted, due to the fact that we cancelled most of our discussions in January in Rolle following the death of Francesco Palla. This will now be re-activated. Let me stress in this frame that we definitely need to work on our professional work ethics. You probably are aware that a false claim of the detection of a gamma ray signal related to the detection of gravitational waves from a coalescing black hole system gave rise to a flood of theoretical explanations within days if not hours. This contributes to undermine the credibility of science in general: What is the value of the understanding we gain of real phenomena, if we can also "explain" any fluke in the data.

Let me finish by stating that we should have had a happy day today making the transition towards the presidency of Francesco Palla. He was looking forward to taking over this position and I was happy to leave the society in his able hands. This is not to be. Council decided to react to Francesco's death by delaying the change of presidency by one year, by asking Roger Davies to serve as the next president and by asking him to serve in the intervening year as president elect. Both Roger and I agreed with this procedure. I'll keep the helm for another year and will use the time to help Roger become familiar with the inner workings of our society. Let me also mention in this sad register that the society also lost past president Jean-Paul Zahn during the time since the last general assembly. Jean-Paul had always been a keen actor on the EAS scene. I profited often from lively, constructive and pleasant conversations with him.

Astronomers go, other come. It is rewarding in this sense to see so many younger colleagues attending this meeting.

Thierry Courvoisier (president EAS)

The scientific organising committee, co-chaired by Susanne Aalto and Nick Kylafis, managed to produce an exciting scientific program with plenary sessions, parallel symposia, and the general assembly including the award of prestigious prizes. The Lodewijk Woltjer lecture was given by Thibault Damour, in honour of his work on General Relativity and in particular the prediction of gravitational waves produced by coalescing black-hole binaries such as recently observed. The Tycho Brahe Prize was awarded to Joachim Truemper, recognising his visionary development of X-ray instrumentation (such as the ROSAT satellite) and the discovery of cyclotron lines in neutron star spectra. A special plenary session was organised in memory of Francesco Palla, who passed away in the night of January 26, 2016, in Switzerland, where he was to attend a meeting of the EAS Council. In the presence of his wife and daughters, Filippo Mannucci, Thierry Courvoisier and Daniele Galli remembered him for his scientific work and personality.

The scientific program covered the full range of astronomical topics, from the outskirts of galaxy clusters to the central engines of active galactic nuclei, from supernovae to interstellar gas and dust, and planet formation. Also the recent developments in astronomical instrumentation were highlighted: Gaia, VLT/MUSE, far-infrared space astrophysics, time-domain astronomy, CMB polarisation and high-energy gamma-ray astronomy. Also a dozen special sessions were organised providing a lot of choice (and difficult decisions on which sessions to attend) to the participants.

EWASS 2016 was a great success and provided a comfortable platform for European astronomers, as well as their colleagues from other continents, to present their recent work, to meet and informally discuss, and to enjoy the warm and hospitable atmosphere in Athens. The EAS hopes to welcome you (again) at EWASS 2017 in Prague, from 26 to 30 June, 2017.

Lex Kaper (EAS councillor overseeing the EWASS organisation)

The proposed sessions have been divided into 12 areas according their topic:

1. Astro Teaching/Funding/Vision/Plans
2. Planets
3. Astrometry
4. Stars, Spectroscopy
5. Star Formation
6. Feedback
7. Star Clusters, Galaxies, Galaxy Clusters
8. Strong Gravity, X-rays, High-Energy
9. Gravitational Waves
10. Cosmology
11. Software, Big-Data
12. Instruments, Ground and Space

In September - October 2016 all proposals were discussed by the SOC, and by the end of October 2016, the SOC reached its conclusion on the overall programme. Discussions with the proposers of the individual sessions will take place in the first half of November, before announcing the final programme by the end of November 2016.

Jan Palouš
SOC chair

EWASS 2017 website

The prize carries a monetary reward of 6000 Euro. Short biographies of previous years' awardees and full details regarding the prize are to be found on the EAS website. There are no restrictions to the nationality of the candidates nor to the country of origin or residence. Nominations are only accepted through a web form accessible for EAS members. The deadline for 2017 nominations is Wednesday, 30 November 2016.

The Tycho Brahe Prize is awarded in recognition of the development or exploitation of European instruments or major discoveries based largely on such instruments. The Tycho Brahe Prize is funded by the Klaus Tschira Stiftung, a German foundation, which was established by the physicist Klaus Tschira in 1995 as a non-profit organization. The Klaus Tschira Stiftung promotes the advancement of the natural sciences, mathematics, and computer science, and wants to raise appreciation for these fields.

Joachim Ernst Trümper was born in 1933 in Haldensleben. He finished the high school in 1951 in Bernburg and spent a year in industry as an apprentice in electro-mechanics, since he was not admitted to an university in the GDR for political reasons. In 1952 he succeeded to enroll at Halle University to study physics. In 1955 he moved (illegally) to Hamburg and in 1957 to Kiel.

In his PhD work (1957-59) at the universities of Hamburg and Kiel, he developed the first triggered spark chamber and used such a device in 1960 to measure the spectrum of cosmic ray muons from the Zugspitze mountain. He continued to work on high-energy cosmic rays and initiated the Kiel extensive air shower experiment aiming at solving the problems of the chemical composition of cosmic rays in the "knee region". After the discovery of pulsars in 1967, J. Trümper turned his attention to this new field. In 1969-70, on sabbatical leave from Kiel, he visited the MPE in Garching and decided there to start a programme of observational X-ray astronomy in Germany. This materialised in 1971 when he became Director of the Astronomical Institute of the University of Tübingen (AIT) and started a competitive hard X-ray balloon programme. The stratospheric balloon observations continued even after his appointment in 1975 as Director of MPE, leading to unprecedented observations of the cataclysmic variable AM Herculis and the black hole binary Cygnus X-1. The most important discovery was, however, the detection of a cyclotron absorption line in Hercules X-1. At an energy of ~40 keV, the line indicates a magnetic field of ~ 5e12 Gauss, which was the first direct measure of the extreme magnetisation of neutron stars. As a follow-up to the balloon programme the MPE/AIT group turned to space projects with the development of the hard X-ray spectrometer HEXE operating from 1987 to 2001 aboard the Soviet/Russian Mir Station. HEXE discovered in particular delayed X-ray emission from the nearby supernova SN 1987A.

The preparatory work for the Röntgensatellit (ROSAT) was initiated by J. Trümper already in 1972 in collaboration with Carl Zeiss, with the goal to improve the mirror performance for large imaging X-ray telescopes. This led to two technological breakthroughs: the use of Zerodur for X-ray optics, and the reduction of the mirror roughness to only 2.5 A. Based on these achievements, he proposed an early version of ROSAT already in 1975, as an element of the German space programme. A few years later USA and UK became involved, but Germany kept the leadership of the project and built at MPE the two main detectors of ROSAT. MPE also built a powerful long X-ray test and calibration facility, which was not only used for ROSAT, but then also for all major European and US X-ray satellites, including EXOSAT, BeppoSAX, Chandra, XMM-Newton and Swift. ROSAT was launched in 1990 and operated until 1999 impacting strongly on many fields of astrophysics with about 4,300 refereed publications and around 160,000 citations. The ROSAT all-sky survey yielded an unprecedented detailed view of the diffuse soft X-ray emission from the Galaxy including many supernova remnants, and about 125,000 discrete sources.

Besides being the principal investigator and the director of the observatory, J. Trümper was personally involved in a number of ROSAT highlights. These include in particular the famous X-ray picture of the moon, the unexpected discovery of X- rays from the comet Hyakutake, the discovery of the first millisecond pulsar in X-rays, and the ROSAT deep and ultra-deep surveys that showed that compact sources like quasars account for most of the extragalactic X-ray background at ~1 keV.

The MPE, under the directorship of J. Trümper from 1975 to 2001, also actively prepared the post-ROSAT era with several instrumental developments. These include the low- energy transmission gratings for Chandra and the complex mirror system for XMM- Newton. To develop X-ray CCDs for the PN-camera of this ESA cornerstone mission, J. Trümper founded a dedicated semiconductor laboratory, which continues developments for the detectors of the future eROSITA and ATHENA space missions. After his retirement from the MPE directorship in 2001, he is continuing his scientific work at the institute. Since 50 years his hobby is sailing, currently on an H-Boat on the nearby Chiemsee.

The very long and successful career of J. Trümper resulted in an impressive list of more than 700 publications among which almost 300 are refereed papers and totalising nearly 20,000 citations so far.

The Lodewijk Woltjer Lecture, named after the Dutch astronomer and former IAU president Lodewijk Woltjer, honours astronomers of outstanding scientific distinction.

Thibault Damour was born in 1951 in Lyon. After studies at the Ecole Normale Supérieure de la rue d'Ulm (1970-1974), he obtained his Thèse de Doctorat de troisième cycle in 1974 (Université de Paris VI), and, later, his Thèse de Doctorat d'Etat en Sciences Physiques (Université de Paris VI, 10 January 1979). He started his career (1977-1989) as researcher at the Centre National de la Recherche Scientifique (CNRS). Since 1989 he is permanent professor at the Institut des Hautes Etudes Scientifiques (IHES).

Thibault Damour is a theoretical physicist working on consequences of Einstein's theory of General Relativity, and its String Theory extensions. He has made lasting contributions on: the theory of black holes, the dynamics and relativistic timing of binary pulsars, the generation of gravitational waves, the motion and coalescence of black holes, as well as several aspects of early cosmology. He has introduced in 2000 (with several collaborators) a new method for describing the motion and gravitational radiation of coalescing binary black holes, which gave the first prediction of the gravitational wave signal observed by LIGO in September 2015. His work was crucially used for interpreting the observed signal and measuring the masses and spins of the two coalescing black holes.

The FONDATION MERAC (Mobilising European Research in Astrophysics and Cosmology) is a non-profit foundation started in 2012 with headquarters in Switzerland to recognise and support young European astronomers. There are yearly three MERAC Prizes awarded by the European Astronomical Society. The prizes of 20,000 Euro are for each of the three categories (Theoretical Astrophysics, Observational Astrophysics, and New Technologies). The prizes alternate by year for Best Early Career Researcher Prizes (on odd years), and Best Doctoral Thesis Prizes (on even years). The awardees are also eligible for further support from the FONDATION MERAC.

The 2016 MERAC Prize for the Best Doctoral Thesis in Theoretical Astrophysics is awarded to Dr Maria Petropoulou for her thesis on radiative instabilities and particle acceleration in high-energy plasmas with applications to relativistic jets of active galactic nuclei and gamma-ray bursts. Maria Petropoulou's PhD thesis has a main focus on the theoretical study of plasma properties in compact energetic sources such as Active Galactic Nuclei (AGNs) and Gamma Ray Bursts (GRBs). Such extremely luminous sources in remote galaxies emit gamma-rays originating in a relativistic jet powered by a black hole. While most studies consider only the electrons in the jet and neglect the influence of the protons, Maria Petropoulou developed equations for a full treatment of plasmas containing magnetic field, relativistic protons and electrons, and photons. She then solved these equations via both numerical and analytical methods to describe the radiative instabilities in the ejected plasmas, which exhibit a rich temporal behaviour of prey-predator type. As a final step, she confronted her model to observations of the archetypical gamma-ray emitting blazar 3C 279. A theoretical study of the spectral and timing emission of GRB afterglows complements her PhD work.

The PhD thesis of Maria Petropoulou was entirely conducted at the University of Athens, Greece, under the supervision of Prof. Apostolos Mastichiadis. She has been awarded the "Best PhD Thesis Prize 2015" from the Hellenic Astronomical Society. Just before her PhD thesis defence, she has been awarded the NASA Einstein Fellowship for postdoctoral research. She is now a postdoctoral Einstein Fellow at Purdue University, West Lafayette, USA.

The 2016 MERAC Prize for the Best Doctoral Thesis in Observational Astrophysics is awarded to Dr Yingjie Peng for his thesis on the simplicity of the evolving galaxy population and the origin of the Schechter form of the galaxy stellar mass function. Yingjie Peng's PhD thesis focused on the analysis of high quality data from large sky surveys both locally and at high redshift, and introduced a novel phenomenological, observationally-based approach to study the formation and evolution of the galaxy population. The goal was to use the observational material as directly as possible in order to identify the simplest empirical "laws" for the evolution of the population. This approach has successfully explained the origin of the Schechter form of the stellar mass function and reproduced many observed essential features of the evolving galaxy population over cosmic time. The associated papers (Peng et al. 2010 & 2012) describing this simple and innovative approach have become some of the most highly cited papers in galaxy formation and evolution.

The PhD thesis of Yingjie Peng was carried out at the Institute for Astronomy at ETH Zurich, Switzerland between October 2007 and September 2012, under the supervision of Prof. Simon Lilly. After his PhD, He then moved to the UK as a research associate at Cavendish Laboratory, University of Cambridge and was awarded the prestigious Royal Astronomical Society Research Fellowship in 2015 for his high-impact research in observational cosmology. In October 2015, he moved from Cambridge to Beijing, China, joining the Kavli Institute for Astronomy and Astrophysics at Peking University, as a tenure-track Assistant Professor.

The 2016 MERAC Prize for the Best Doctoral Thesis in New Technologies is awarded to Dr Oliver Pfuhl for his thesis on an innovative design of two subsystems for the VLTI instrument GRAVITY: the fibre coupler and the guiding system. Oliver Pfuhl started his PhD in 2008 on the GRAVITY project and contributed to the overall design of this new VLTI instrument. He developed two key-components, the fibre coupler and the guiding system, which are key for enabling waveguide based stellar interferometry and for achieving the required astrometric accuracy and stability. The fibre coupler he designed is unique for its compactness, elegance, and innovative use of modern technology. The unit offers all the functions necessary for precision control of the optical path, including tip/tilt-, pupil-, and piston control, field de-rotation, and polarisation control. He also made an innovative design for the guiding system, which actively corrects for tilt- and pupil errors resulting from numerous reflections over 100m of optical path between the telescopes and the instrument. The astrophysical part of Oliver Pfuhl's thesis is a spectroscopic study of more than 500 stars in the nuclear star cluster at the Galactic centre, which shows that this cluster formed most of its stars more than 5 billion years ago.

The PhD thesis of Oliver Pfuhl was carried out under the Supervision of Prof. Reinhard Genzel and Dr. Frank Eisenhauer at the Max-Planck-Institute for extraterrestrial Physics, Garching, Germany, and the Ludwig-Maximilian University, Munich, Germany. He was awarded the Universe PhD Award for the best experimental dissertation by the Excellence Cluster for Astronomy in the Munich area. After his PhD in July 2012, Oliver Pfuhl took a postdoctoral position at MPE. He is currently seconded to ESO Chile for one year to ensure that GRAVITY is successfully commissioned at the VLTI.

The symposium was organised in seven sessions, with 36 presentations, over the days 4-6 July 2016. Following the successful open model adopted at the 5th GREAT Plenary in 2012, the community were invited to submit their proposed talk titles and abstracts on the meeting wiki. The final meeting programme was then generated by the SOC based on those contributions. The symposium was attended by over 100 people. All sessions were well attended, with lively discussion after each presentation.

Session 1 contained invited presentations covering the Gaia project, in particular the upcoming first data release. Prusti presented the status of the Gaia mission, including examples of the data collected and an overview of the expected science performances. Brown presented a preview of the contents of Gaia DR1, showing some statistics on the contents of Gaia DR1 and explaining the known limitations of the first data release. The presentation by Brown was closed with the announcement that Gaia DR1 would take place on September 14 2016. The subsequent presentation by Arenou discussed in detail how the validation of the Gaia DR1 results was done. Walton closed the session with and overview of the GREAT networking activities, including the proposals that were submitted to obtain continued funding for GREAT (through for example the COST scheme).

Session 2 was dedicated to providing more details of the data processing that was done for Gaia DR1. An overview of the photometric processing and the expectations for photometry in future Gaia data releases was provided by Busso and Jordi, the latter noting how Gaia will become the reference photometric survey for future space and ground based surveys. Veljanoski presented a specific set of statistical tools used in the validation of Gaia DR1, while Clementini previewed the Cepheid and RR Lyrae data (light curves and characterization) that are part of Gaia DR1. Bellas-Velidis presented the expected performance of Gaia for unresolved external galaxies and Blomme provided a status update on the Gaia radial velocity spectrograph processing.

Session 3 focused on the Gaia archive system and the data access facilities. The aim was to prepare the astronomical community ahead of Gaia DR1. Salgado described the details of the archive itself, including the various options for accessing Gaia DR1 data. Mora gave a demonstration of the workings of the Gaia archive, going through several example queries executed on simulated data. Finally, Kordopatis provided a preview of RAVE DR5, which will include a cross-match with the Gaia DR1 sources for which proper motions and parallaxes are available.

Session 4 was dedicated to science on transients with Gaia. Hodgkin presented the status of the Gaia photometric alerts effort, summarising the properties of the alerts published to date and showing the latest evolution of the alerts tools for users. Blagorodnova discussed in more detail the classification of transients based on Gaia's BP/RP spectra. Jonker discussed the prospects for discovering white dwarf tidal disruption events with Gaia, while Wyrzykowski discussed the possibility of Gaia discoveries of TDEs around supermassive black holes. Roelens provided insights into the way short time scale variables are identified and characterised in the DPAC pipelines and Tanga discussed the identification and processing of solar system objects by Gaia, including the option to alert on newly discovered near earth objects.

Session 5 contained presentations on the preparations for the scientific exploration of Gaia data. The possibilities for extragalactic science were discussed by Kontizas. Marchetti presented his machine learning algorithm for the search for hypervelocity stars in the Gaia data, which he plans to test extensively on Gaia DR1. The synergies between optical and radio astrometry were discussed by Forbrich. Vickers presented methods to determine stellar ages from the combination of Gaia and LAMOST data, and the session was closed by Poggio with a discussion on the study of the Galactic warp with Gaia data.

Session 6 focused on the distance scale which is of course expected to undergo major improvements with future Gaia data releases. The expected improvements in the physics of Cepheids and RR Lyrae variables was discussed by Marconi, while Kervella focused on the synergy between Gaia measurements of Cepheids and optical interferometry of those stars. Anderson presented his efforts at cleaning up calibration samples for the Cepheid Period-Luminosity relation through the use of radial velocities to weed out binaries. The Cepheids and RR Lyrae in the Magellanic clouds were discussed by Ripepi and Muraveva, respectively. Ruiz Dern closed the session with a discussion on the future calibration of the Red Clump star luminosities with Gaia.

Session 7 contained presentations on synergies between Gaia and other surveys and on new astrometric instrument initiatives. Cellino discussed ground based observations that are needed to complement Gaia's observations of minor bodies in the solar system. Ranalli presented an in-depth study of the detection and characterisation of exoplanets with Gaia, noting the benefits of extending the Gaia mission for the study of long-period systems. Vallenari presented an overview of the synergies between ground and space for open clusters studies and provided a preview of the improvement in the study of internal cluster kinematics with Gaia, showing a comparison of Tycho-2 and Gaia DR1 proper motions. Athanassoula discussed N-body models for our Galaxy in the context of future Gaia data releases. Feltzing discussed ground based spectroscopy projects aimed at complementing Gaia, in particular 4MOST and WEAVE. The session was closed by a presentation from Leger on the proposed astrometry mission Theia, which aims at sub-microarcsecond differential astrometry.

During the closing remarks for Symposium 1, Walton summarised highlights from the symposium, noting that each GREAT symposium has attracted a larger number of talks and attendees. In addition to the main speaker programme, there were 21 short poster presentations. The next GREAT plenary would be proposed as a symposium at the 2017 EWASS in Prague, Czech Republic.

More info about this symposium may be found here.

Anthony Brown (Leiden Observatory, Leiden, Netherlands)
Nicholas Walton (Institute of Astronomy, University of Cambridge, UK)
Timo Prusti (ESTEC, Noordwijk, Netherlands)

The symposium discussed the most compelling and unique science cases for the FIR spectral region and the required technical capabilities, as well as the status of the FIR missions currently under consideration. The symposium concluded with a lively panel discussion aimed at formulating a community action plan for the future. A broad range of topics was covered, from the early universe, galaxy formation and evolution, interstellar medium and star formation, protoplanetary and debris disks, evolved stars, and solar system, to key technological aspects, including telescope architecture and detectors. Several planned FIR facilities have been presented, including SPICA, FIRSPEX, and Millimetron, as well as the FIR Roadmap, currently under development by a group of European scientists.

Up to 40-50 participants attended the eight symposium sessions during three days. The program consisted of 15 invited talks, 13 contributed talks, and 2 poster presentations. In conclusion, the science case for future FIR space missions is compelling. NASA has recently commissioned a study of the Origins Space Telescope, a possible flagship mission for the next decade, in which Europe may participate by contributing a heterodyne instrument. It is thus imperative that the European science interests are well formulated. Future EWASS meetings will provide an excellent platform for continuing this important discussion.

More info about this symposium may be found here.

Darek Lis (LERMA, Observatoire de Paris, France)
Maryvonne Gerin (LERMA, Observatoire de Paris, France)

Until recently, more than about 70% of the cluster's volume, where most of the mass accretion processes onto the main halo is occurring, has remained essentially unexplored. In these regions, the distribution of the hot gas (traced with both X-ray and SZ signal) is expected to be clumpy and asymmetric, with non-negligible effects from non-thermal processes (like, e.g., turbulence, bulk motions, magnetic fields, particle acceleration) that can be also investigated through radio observations. The overall dark matter distribution has started to be mapped through the weak lensing signal and the galaxy distribution, by which also the evolution of the properties of the accreting galaxies as the environment changes (from low to high density regions) can be traced.

Eight invited, 21 contributing and 7 short talks were presented in front of an audience of about 70 researchers over the two days of the Symposium, covering several subjects, from the mass assembly and hierarchical structure formation processes to the processes responsible of the ICM heating and virialisation of accreting hot gas; from the non-thermal phenomena in cluster outskirts (radio relics, accretion shocks, turbulence) to the filaments and the quest of the missing baryons.

State-of-the-art research on the clusters' peripheries has been presented, both from multi-band (optical, radio, SZ, and X-ray) observations, and numerical simulations and theoretical models. An overview of the present limitations affecting the analysis of these regions has been given, and a discussion has been triggered on how these problems can be overcome with the next generation of instruments. The symposium has reached the goal of keeping the momentum high, and the discussion lively, on the physics and the problematics concerning the peripheries of the galaxy clusters.

More info about this symposium may be found here.

Dominique Eckert (University of Geneva, Switzerland)
Stefano Ettori (INAF-OA Bologna, Italy)

Impressive progress has been made in recent years, both in theory and observations, driven by the wealth of new results from satellites like Chandra, XMM-Newton, Suzaku and NuSTAR. The EWASS 2016 Symposium 7, held on 7-8 July, provided an opportunity to review and summarise the most recent observational results and the latest theoretical developments in this relatively new and rapidly developing field. We hosted 9 invited reviews, 18 contributed talks and 17 posters. The symposium was attended by 60 to 80 people, who actively contributed to lively discussions during all sessions.

Session 1 focused mainly on the theoretical and numerical modelling of the accretion flow in AGN. A. Sadowski presented a detailed review of the state of the art methods of simulating accretion flows on compact objects. G. Chartas described a new technique for measuring the inner edge of the accretion flow in thin discs using observations of microlensed AGN. A. Rozanska discussed the properties of warm dissipative and optically thick coronae on top of a standard accretion disc in AGN and the role of magnetic fields. B. Czerny presented results from a detailed study of RE J1034+396 where an optically thick Comptonising medium is present in the inner part of its accretion flow, while B.You discussed the role of winds on the accretion flow properties.

Session 2: What produces the X-ray continuum in Active Galactic Nuclei? This simple and fundamental question has been the subject of active research and debate since the first X-ray observations of AGN. P. O. Petrucci presented a comprehensive review of theoretical models of the so-called X-ray emitting ?corona?. The heating mechanism, temperature and geometry of this corona is difficult to probe observationally, but in recent years, we have begun to make new advancements. A. Marinucci and G. Lanzuisi presented the the hard X-ray view of AGN coronae as probed by NuSTAR. This high-energy bandpass has allowed for the first robust measurements of the temperature of the corona in AGN, allowing for new constraints on this component of the accretion flow. E. Behar presented the results from new X-ray and mm-wave observations of nearby Seyferts and discussed their consequences on the X-ray coronal properties, while S. Bianchi discussed the latest results regarding intrinsically weak BLRs in AGN, and their implications in the accretion physics.

Session 3: In recent years, X-ray reverberation has opened a new way to investigate the inner accretion flow around supermassive black holes. This session's talks addressed this topic, discussing observations and models of X-ray reverberation in AGN. E. Kara, in her review, discussed the latest XMM-Newton and NuSTAR observations of the high-frequency variability which have shown that the soft excess, broad iron K line and Compton hump lag behind the continuum emission, corresponding to light travel distances of a few gravitational radii. Beyond simply detecting reverberation, we are beginning to understand that spectral-timing observations of inner disc reverberation are necessary for modelling both the energy of the photon and its arrival time in order to maximise the information in a given observation (review by A. Young, and talk by M. D. Caballero-Garcia). M. Parker discussed the results of the application of the principal component analysis to the AGN X-ray variability, while D. Emmanoulopoulos presented a novel way to study X-ray reverberation with power-spectral analysis techniques.

Section 4: While X-ray spectroscopy of AGN has been historically the primary tool to understand the nature of the central engine (review by A. L. Longinotti), coupling of spectroscopy and timing have recently opened a new window. The geometry of AGN outflows (accretion disk winds, "warm absorbers") is now pinpointed with unprecedented accuracy in systems exhibiting short (i.e.,hours; C. Silva), and long (i.e, days to months; M. Medhipour) time-scales thanks to advanced data analysis techniques (reverberation) and multi-wavelength campaigns. This contributes to a

Session 5 focused on X-ray missions, currently operating as well as the planned ones. The Project Scientist for XMM-Newton, N. Schartel, discussed the main scientific highlight results based on XMM-Newton observations of AGNs during the last 15 years. With about 300 refereed papers published each year, XMM-Newton is one of the most successful scientific missions of ESA ever. G. Dewangan introduced the recently launched India?s first multi-wavelength space astronomy mission, Astrosat. He presented a brief overview of instruments onboard Astrosat, results based on the first observations performed, and future plans for AGN science with this satellite. F. Muleri and G. Matt presented the case for X-ray polarimatric observation which have the potential to open up a new wealth of information that will help us better understand the X-ray emission from compact objects. They also presented a candidate for the first X-ray polarimetry satellite mission, XIPE, and its possible contribution to the science of AGN.

Finally, during the 6th Session of the Symposium, the focus was set onto larger scales and the broader scope of the the cosmic evolution of AGN. Y. Ueda argued in his review talk that an accurate deconvolution of the high-energy spectral energy distribution of obscured AGN is the key to solving two fundamental problems in modern astrophysics: the concurrent evolution of accretion black hole and host galaxy, and the Cosmic X-ray Background. K. Ebisawa briefly shifted the tone back to the central source and the investigation of X-ray spectral diagnostics of the physical environment around the central black hole. The next talks addressed the innermost parsec surrounding the accreting super-massive black hole. The availability of sensitive measurements above 10 keV (Swift/BAT, NuSTAR) led to unprecedentedly accurate constraints on the nature of the optically thick reprocessing in the AGN environment (R. Boissay), and to compare the properties of the torus in the dusty and dust-free regime (M. Guainazzi). The symposium ended with an exciting possibility that the AGN studies may be able to offer: if we understand quasars observationally, we could perhaps use them as efficient standard candles for the determination of cosmological parameters complementary to supernovae (G. Risaliti).

More info about this symposium may be found here.

Michal Dovciak (Astronomical Institute of the Czech Academy of Sciences, Czech Republic)
Matteo Guainazzi (ESAC/ESA)
Erin Kara (University of Maryland, USA)
Iossif Papadakis (University of Crete, Greece)
Andrew Young (University of Bristol, UK)

Understanding these interactions is therefore crucial for all kind of astrophysical objects, from early Universe galaxies to the formation of the Solar System. The aim of the symposium S8, "Interstellar dust and gas coupling: liking observations, models and laboratory astrophysics", was to present and discuss recent studies from experimentalists, theoreticians and observers in order to address the interplay between gas and dust from different perspectives. There were a total of 9 invited talks, 18 contributed talks, and several poster presentations.

The first day featured one session on laboratory astrophysics, presenting the latest results on different processes driving the interplay between gas and dust. In the second session, theoretical modelling that are used to model such processes were presented. In the last session, Astrophysical models and observations of Dark clouds and pre-stellar cores showed our current understanding of the gas and dust interplay in cold environments.

The second day was dedicated to astrophysical models and observations. The first sessions focused on gas and dust interplay in different environments. ranging from photo-dissociation regions, to disks, comets, and shocks. The last session featured several observational studies of the dust composition and properties in galactic and extragalactic environments.

Our original ambition in organising this Symposium was to bring together scientists from different backgrounds to determine how current astrochemical models do interpret observations and how well we understand the different processes involved in the interplay between gas and dust. The many discussions occurring during the two days Symposium highlighted the need for multidisciplinary studies to understand processes occurring in space. In addition, possible future observations or experiments that would be beneficial to our current understanding were discussed.

The organizers wish to thank all the speakers for making this symposium a great success.

More info about this symposium may be found here.

Stephanie Cazaux (Kapteyn Institute, Netherlands)
Gisela B. Esplugues (Kapteyn Institute, Netherlands)
Vianney Taquet (Leiden Observatory, Netherlands)
Valentine Wakelam (University of Bordeaux, France)
Serena Viti (UCL, UK)
François Dulieu (LERMA, France)
Paola Caselli (MPE, Germany)

While this has significantly increased our understanding of GRBs, questions still remain on the nature of the central engine and new features and phenomena are still being discovered, such as ultra-long duration GRBs (ULGRBs), of which one was recently linked to a super-luminous supernova. Furthermore, GRBs are proving to be useful probes of cosmic star formation history and cosmology, and much research is being performed to fully exploit their advantages. This symposium aimed to bring together observers, theoreticians and numerical modellers to address these issues. The program covered topics ranging from the central engine through to their afterglows, association with supernovae and their host galaxies.

The first day of our symposium was dedicated to recent progress in our understanding of the prompt gamma-ray emission and the central engine producing these enigmatic events. We had two very interesting review talks by Luciano Rezzolla and Omer Bromberg. Luciano discussed recent results on numerical modelling in full general relativity of the inspiral and merger of binary neutron stars and how it can be used to improve our understanding of the phenomenology of short gamma-ray bursts, particularly in light of the new observational window being opened up with the detection of Gravitational Waves. Omer reviewed the outflows of GRBs in particular discussing instabilities and energy dissipation in relativistic MHD jets and how GRBs are connected to superluminous supernovae. Other presenters discussed the emission mechanisms of the prompt emission phase and whether the emission could retain memory of the central engine, heavy element production and progenitor models such as magnetars. We also had an interesting talk related to the future mission THESEUS.

The second day was dedicated to the afterglow phase, the GRB-supernova (SNe) connection and host galaxies of GRBs. We had very informative talks by Zach Cano and Daniel Perley. Zach discussed the connection between GRBs and SNe and how they can potentially be used to constrain the Hubble constant and whether any differences exist between GRB-SNe and ULGRB-SN. Daniel Perley reviewed our current knowledge of the observational properties of GRB host galaxies. In particular suggesting that long GRB host galaxies are more typical than previously thought and that new observations of short GRBs are providing clues about the progenitor's nature and the delay time from formation to explosion. In addition, regarding the afterglow phase, speakers presented work on GRB afterglow correlations, variability in early afterglow phase, what we could expect to observe many years after the GRB and a discussion on the longest detected X-ray afterglow, GRB 130427A, observed for ~1000 days after the main explosion. Speakers addressing host galaxies of GRBs, explored topics such as dust, gas kinematics, absorption features, abundances in DLAs, comparison between GRB hosts, superluminous and broad line IC SNe and interesting observations were presented of host galaxies performed by MUSE and VIMOS.

The symposium was well attendance with around 30-50 people attending at any one time. The presenters were from a broad range of European and international countries and several of these talks were presented by young researchers highlighting the continued interested in this area. The fact that there were symposia and special sessions on topics related to GRBs particularly made EWASS 2016 very productive for all. The organizers wish to thank all the speakers for making this symposium a great success. Particular thanks go to the organizers of the EWASS 2016 for having made this event possible.

More info about this symposium may be found here.

Ioannis Contopoulos (RCAAM, Academy of Athens, Greece)
Samantha R. Oates (University of Warwick, UK)
Dimitrios Giannios (Purdue University, USA)
Andrew Levan (University of Warwick, UK)
Massimiliano De Pasquale (MSSL-UCL, UK)
Alberto Castro-Tirado (IAA-CSIC, Spain)
Patricia Schady (MPE, Germany)
Myrto Symeonidis (MSSL-UCL, UK)
Antonios Nathanail (ITP, Goethe University, Frankfurt, Germany)

However, observational evidence for such a dramatic effect of AGN-induced outflows is far from clear. The difficulty in quantifying its galaxy-wide impact is a result of the great complexity of its phenomenology. It depends on three dimensional effects, the structure of the multi-phase interstellar medium (ISM) and the interplay between different mechanisms acting across a wide variety of spatial scales. Likewise, the theoretical understanding of outflows and their impact is rudimentary at best.

The aim of the symposium was to bring together experts on the observational and theoretical studies of the outflow phenomenon in galaxies to establish the current status of the field, discuss the critical uncertainties to be dealt with and define the best strategies to achieve progress in our understanding of the feedback generally and its role on galaxy evolution. These goals were nicely achieved by our 7 invited speakers, and also by the presenters of the 18 contributed talks and 22 posters. Thanks to those presentations, we had the opportunity to see new observational results from ALMA, X-SHOOTER, MUSE, SINFONI, as well as the latest theoretical predictions from simulations.

The take-home message of the symposium was that although we have definitely advanced in our strategies to identify the signatures of galactic outflows (AGN- and starburst-driven) in galaxies at different redshifts, our ability to evaluate their potential impact on galaxy evolution is still limited. The lively debate on this regard during the workshop promoted enriching scientific discussions. Different approaches are being promoted to elucidate the controversy and will hopefully boost a substantial advance in the topic in the near future. For example, studies of the impact of the outflows on the different gas phases across different spatial scales, detailed studies of individual galaxies, statistical studies of large galaxy samples at different cosmic epochs, a more accurate characterisation of the geometry, size and physical properties (e.g. density) of the outflows and more realistic simulations adapted to account for the great complexity of the feedback phenomenon.

More than 100 people attended the symposium, and although the program was too tight for discussion sessions, there were plenty of questions and participation from the audience. The organizers would like to thank the SOC, all the speakers and participants for making the symposium a success, and the EWASS organizers for giving us the opportunity to hold it.

More info about this symposium may be found here.

Cristina Ramos Almeida (Instituto de Astrofisica de Canarias, Spain)
Montse Villar Martin (Centro de Astrobiologia, Spain)

In recent years, the exploration of our Universe in the high energy end of the electromagnetic spectrum (from ~1 GeV to ~100 TeV) has experienced a major boost, mainly thanks to the current generation of satellite-borne and ground-based gamma-ray observatories such as AGILE and Fermi-LAT in the high-energy (1GeV < E < 100 GeV) band, and MAGIC, VERITAS, H.E.S.S. and Milagro in the very-high-energy (~100 GeV < E < ~10 TeV) band. These instruments have built up catalogues containing hundreds of sources. In the near future, the field is expected to experience a new major revolution with the advent of the next generation of instruments such as HAWC (now starting operations) and the Cherenkov Telescope Array (CTA, under construction, and which will be operated as an open observatory with observational proposal from the whole Astrophysics community).

Exploration in the high- and very-high-energy bands pursues three major scientific goals, namely:

• understanding the mechanism at work in cosmic particle accelerators;
• probing extreme environments such as neutron stars, black holes, relativistic jets, winds and explosions; and
• exploring the frontiers of physics by searching for dark matter, axion-like particles, or quantum gravitational effects on photon propagation.

The synergies between high- and very-high-energy gamma-ray astronomy with observations in other wavelengths are instrumental to achieve all these goals. The aim of our symposium was therefore to strengthen the links between the gamma-ray community with the astronomy and astrophysics community at large. In this first symposium of the series, we discussed the status of the field, recent experimental and theoretical results and prospects for future instruments and technical developments. Future symposia will focus in specific areas of synergies between high- and very-high-energy gamma-ray astronomy and other astronomical bands.

The symposium was divided in four blocks, namely: instrumentation, Galactic astrophysics, extragalactic astrophysics and fundamental physics. For each block we had one or several invited review talks by world experts, such as Brenda Dingus, Julie McEnery, Elisa Pueschel, Luigi Piro, Elena Orlando, Constantinos Kalapotharakos, Jerome Rodriguez, Jacco Vink, Savvas Koushipappas and Troy Porter. In addition, there were contributed talks and poster sessions presenting recent results in the field. The symposium was closed by a general review talk by Werner Hofmann.

For the next EWASS edition, we are proposing the second symposium of this series, with title "Radio/VHE Galactic Plane surveys: synergies between CTA and SKA". We are looking forward to meeting you in Prague!

More info about this symposium may be found here.

Javier Rico (Institut de Fisica d'Altes Energies, Barcelona, Spain)
Juergen Knoedlseder (Institut de Recherche en Astrophysique et Planetologie, Toulouse, France)

Intriguing transients have been found also at other wavelengths: ultra-long gamma-ray bursts (GRBs) have been shown to constitute a separate class of outbursts than regular GRBs; In the radio, we still haven't been able to nail down the distance and energetics of the mysterious fast radio bursts (FRBs). Gravitational wave (GW) searches may soon lead to the first robust detections of neutron star mergers and their associated kilonova electromagnetic counterparts.

In this symposium, the program was divided in 6 blocks. Each block was dedicated to a different topic and the discussion was initiated by an invited speaker, followed by contributed talks and poster discussions. In total, we had 6 invited talks, 23 contributed talks and 6 poster presentations. The seminar room was nearly full with more than 60 colleagues attending at all times.

The symposium started with a session on gravitational waves. Marica Branchesi gave a review talk on the recent developments in this exciting field and on the prospects of detecting the electromagnetic counterparts of gravitational waves in the near future. The next session was dedicated to FRBs, where the invited speaker was Evan Keane. We discussed all the exciting discoveries that took place during the last year, including the follow-up of FRBs, the discovery of a repeating FRB and FRB models. We then moved on TDEs with a review talk by Sterl Phinney. The contributed talks covered diverse aspects of TDEs such as their unusual host galaxies and various theoretical approaches.

The second day started with a session on ultra-long GRBs. Invited speaker Andrew Levan sparked the discussion, which continued with talks on the radio emission and the mechanisms powering ultra-long GRBs. The session also included talks on different surveys in the time domain, such as OGLE, Gaia and the Liverpool Telescope. We then moved on to rapidly evolving supernovae and a review of their different sub-classes by Stefano Valenti. The contributed speakers focused on various peculiar kinds of events, their environments and different proposed models. The final session was dedicated to SLSNe. Cosimo Inserra gave an overview talk on the current status of research and other speakers introduced recent discoveries, discussed new sub-classes and presented host galaxy studies.

More info about this symposium may be found here.

Giorgos Leloudas (Weizmann Institute of Science & Dark Cosmology Centre, Denmark)
Iair Arcavi (LCOGT & UC Santa Barbara, USA)

Whereas, regarding the millisecond binary pulsars, astrophysicists had the opportunity to thoroughly investigate the so-called Recycling Scenario: the evolutionary path leading to the formation of a Millisecond Radio Pulsar. The most intriguing phase is certainly the spin?up stage during which, because of the accretion of matter and angular momentum, the neutron star accumulates an extraordinary amount of mechanical rotational energy, up to 1% of its whole rest?mass energy.

In this symposium we explored the many lives of pulsars through presentations from observers and theorists. The meeting took place on the 7th and 8th of July, it featured 26 talks and 10 poster presentations and was well attended.

The first two blocks of the symposium were devoted to isolated pulsars and magnetars, with special focus to their magnetic field structure and evolution from the core to the magnetosphere. Jose Pons reviewed recent observations of neutron stars and their magneto-thermal evolution. Ioannis Contopoulos reviewed magnetospheric models focusing on the dissipative pulsar magnetosphere. Simulation works studying the core, crust and the magnetosphere were presented by Andrea Passamonti, Konstantinos Gourgouliatos and Constantinos Kalapotharakos, respectively. Finally, talks about recent observations of magnetars revealing their magnetic fields, radiative and timing behaviour were given by Sebastian Guillot, Paul Scholz and Fabio Pintore.

The remaining four blocks focused on different aspects of Low mass X-ray binaries.

The main topic of session 3 was the evolutionary paths from Low Mass X-ray Binaries to Millisecond Pulsars, which was reviewed by Francesca D'Antona. Chengmin Zhang showed simulation of how accretion transform NS into millisecond pulsars, while Diego F. Torres presented an observational review of the gamma-ray emission from accreting and transitional pulsars, redbacks, and black widows. The contributed talk by Jonay I. Gonzalez-Hernandez on spectroscopic optical observations of the orbital evolution in black hole X-ray binaries closed the session.

Session 4 started with Michiel van der Klis reviewing the timing properties of Low-Mass X-Ray Binaries and Accreting Millisecond Pulsars. The invited talks by Andrea Possenti and Domitilla De Martino highlighted the radio properties of transitional and radio millisecond pulsars. The session ended with the contributed talk by Andrea Sanna on the orbital evolution of the accreting millisecond X-ray pulsar SAX J1808.4-3658.

Present and Future X-ray missions are of fundamental importance for the study of spectral and timing properties of Low Mass X-ray Binaries. For this reason, Session 5 was devoted to this topic, where Giorgio Matt and Marco Feroci reported on future missions of X-ray polarimetry and the status and perspectives of several missions, namely LOFT, eXTP, LOFT-Probe, MVN-M2 and the possible advancements in our understanding of the compact objects systems and their physical conditions.

The final session dealt with the spectral properties and reflection features of Low Mass X-ray Binaries. Edward Cackett provided a detailed review on spectral studies of Low Mass X-ray Binaries and Accreting Millisecond Pulsars. Mariano Mendez presented an interesting evidence of a resonance mechanism leading to the formation of kHz QPOs. Teo Munoz-Darias suggested a common accretion state scheme for both neutron star and black hole systems. Subsequent contributed talks by Tiziana Di Salvo (Alessandro Riggio), Nikolaos Kylafis, Enrico Bozzo, and Carlo Ferrigno on observational spectral analysis and modelling of Low Mass X-ray Binaries closed the session.

More info about this symposium may be found here.

Konstantinos Gourgouliatos (Department of Applied Mathematics, University of Leeds, UK)
Alessandro Riggio (University of Cagliari, Italy)

Magnetic helicity was imposed in relatively recent decades as a sophisticated physical parameter possibly regulating the relaxation of stellar magnetic fields and the subsequent release of magnetic energy. Helicity was even posed as the key factor responsible for stellar coronal ejecta, in this way constraining further the conditions at stellar habitability zones. The details of the multiple mechanisms involved, from magnetic energy / helicity production and accumulation, to net helicity effects and helicity dissipation, to instabilities of helical fields, to ejecta and their outward propagation, remain elusive and were the subject of invited and contributed talks in the course of the symposium.

The list of invited speakers included helicity pioneer thinkers, theorists, modellers and observers from the solar and stellar communities. In the theoretical front, the magnetic field decomposition giving rise to relatively helical (i.e., toroidal) and non-helical (i.e., poloidal) magnetic fields was discussed along with helicity decomposition into twist and writhe and the strong efficiency of magnetic helicity conservation in solar and stellar conditions.

For magnetically active stars, the topics of fully vs. partially convective dynamos were discussed along with the production of helical toroidal fields and primordial stellar "fossil" fields playing a major role in stellar dynamos. It was also emphasised that magnetic maps of numerous Sun-like stars are now available for study and, indeed, that these maps have been used in existing studies. With the Sun apparently producing no net helicity effects, the validity of this assessment in other stars remains unclear.

Focusing on the Sun, the wealth of existing observations allows studies of helical magnetic flux emergence that stand out as a stunning showcase of solar magnetic complexity. The importance of global solar dynamo studies was amply underlined, along with resulting helicity manifestations in the solar atmosphere, giving rise to global hemispheric effects and further enhancing the observed complexity.

Solar eruptions seem to be intimately related to helicity manifestations in several cases: ideal helical instabilities, resistive conversion into different types of helicity for magnetic flux tubes of finite cross-sections, accumulation of helicity enhancing the eruptive potential of solar magnetic structures and even defining a certain point-of-no-return, beyond which the structure may be forced to erupt at some point. Certain models describe a new twist in the study of solar flares and solar eruptions in general, where flux emergence results in a natural formation of twist giving rise to the observed hemispheric helicity patterns. While these developments are clearly in working progress, with intense - sometimes heated - debates following their unfolding, the breadth and diversity of existing studies powered by the voluminous solar observations are telltale signs of potentially groundbreaking developments building up as we speak.

A topic still far from maturity, applying to both solar and stellar settings, is the propagation of helical eruption products outward from source stars, toward their stellar systems. These ejecta affect different bodies in different ways. Preliminary works suggest that the transport process of solar (and possibly stellar) coronal mass ejections (CMEs) can be reproduced, at least statistically, by means of the helicity conservation principle. More theoretical and modelling work is needed in order to study the efficiency of these propagating CMEs in generating magnetic storms in magnetosphere-shielded stellar-system bodies, but we view the discussion during the Symposium as a meaningful starting point in this direction.

In conclusion, the Symposium afforded its attendees a top-tier snapshot of a vibrant, dynamically evolving field of cosmical magnetism. Due to the proximity of the Sun as a cosmical laboratory, it is perhaps natural that the bulk of existing work seems leaning toward solar physics. Implications for stellar, or even much larger-scale, astrophysics are visible and profound, nonetheless.

The Symposium was sponsored by the European Solar Physics Division (ESPD), a joint Division of the EAS and the European Physical Society (EPS). More info about this symposium may be found here.

Manolis K. Georgoulis (RCAAM of the Academy of Athens, Greece)
Alexander Nindos (Department of Physics, University of Ioannina, Greece)
Dibyendu Nandi (Center of Excellence in Space Sciences India, IISER Kolkata, India)

Addressing SEC is a complex and difficult problem, given the multiple and interconnecting physical domains along with the corresponding disparate physical regimes and spatio-temporal scales that need to be simultaneously considered (Sun, interplanetary medium, magnetosphere). However, significant leaps of progress in our understanding of the physics of SEC have been achieved over the last decade, thanks to the availability of comprehensive data-sets all way through from Sun, the interplanetary medium and in planetary magnetospheres from an armada of recent space missions, as well as from major advances in large-scale simulations and theory. The objective of Special Session SS2 was to supply an overview and outlook of the solar-terrestrial coupling and of space weather.

18 oral presentations (invited, contributed and poster), covering a multitude of solar, interplanetary, and magnetospheric observational and theoretical topics were made during SS2. Despite the tight schedule, significant time was allocated to discussions between the participants.

Viggo Hansteen presented a review of the latest results on the unresolved fine structure in the solar transition region from the latest solar mission (IRIS) and from advanced MHD modelling. Ward Manchester presented MHD simulations of how magnetic energy accumulates in solar active regions from photospheric shear flows driven by the Lorentz force. Loukas Vlahos presented a Fermi model for turbulent reconnection and applied it to the problem of coronal energisation and heating. Manolis Georgoulis presented theoretical and observational results on a sequence of physical processes occurring in certain active regions prior to eruption. Irantzu Santamaria presented MHD modelling results on the high-frequency jet phenomena occurring in the presence of a magnetic null point. Emilia Kilpua presented a review of the latest observational and modelling results on CME propagation in the interplanetary space, as well as specific CME properties and physical mechanisms that could affect their geo-effectiveness. Anastasios Anastasiadis presented a statistical study connecting the properties of Solar Energetic Particle (SEP) events with these of the associated flares and CMEs.

Georgios Balasis presented applications of various tools used in complex system sciences to geo-space observations related to SEC and space weather. Michael Gedalin presented theoretical results on the collisionless relaxation of ion oscillations in shock fronts. Juha-Pekka Luntama presented a review of the European efforts and projects on geospace weather nowcasting and forecasting. Iannis Dandouras presented recent results from the CLUSTER mission on various plasma sources in the terrestrial magnetosphere as a function of the solar forcing. Maria Antonietta Barucci presented observational and laboratory results on the impact of space weather on asteroid's surfaces. Anastasios Anastasiadis presented an operational prediction system for solar flares and SEPs.Ivan Dorotovic presented an observational study of the magnetic induction at the footpoints of coronal loops. Anna Milillo presented a project aiming to observe Energetic Neutral Atoms from the International Space Station. Konstantinos Karampelas presented MHD modelling results of coronal heating and dynamics in simulated coronal loops due to resonant absorption of Alfven waves. Stavros Sklavenitis presented a statistical study of the Kronian magnetic field from Cassini data and investigated the impact of the solar wind pressure. Spiros Patsourakos presented an analysis of SDO data of the accumulated magnetic flux associated with transient brightenings prior to a major CME.

The organizers would like to thank all speakers and participants for a successful and lively special session and the EWASS for the opportunity to organise this session.

More info about this special session may be found here.

Vasilis Archontis (University of St Andrews, UK)
Ioannis Daglis (University of Athens, Greece)
Spiros Patsourakos (University of Ioannina, Greece)
Angelos Vourlidas (JHU/APL, USA)

Despite its importance, the central parts of the Milky Way are not well-understood. We know that it is tri-axial, hosting a strong bar, but recently we have begun to reveal intriguing subtleties, such as the presence of an X-shape structure in density or high-velocity substructure(s) in kinematics. The latter feature has received a lot of attention in the past few months, prompting speculation that this may be due to younger stars at low latitudes. It has commonly been assumed that the bulge population is old, but recent studies such as these or the results from spectroscopy of turn-off stars has uncovered young and intermediate-age populations. Therefore, as the title of this special session alludes to, we covered the various ages of the bulge, from the oldest most-metal poor stars, to these new discoveries of younger populations. As ongoing surveys (such as APOGEE, VVV, Gaia-ESO, etc) are now amassing huge volumes of data, it was the right time to bring together leading theorists and observers to deconstruct the bulge in order to determine its assembly history.

Our session addressed these issues with three distinct themes. We started off with a review by Isabel Perez (Universidad de Granada) who placed the Milky Way in a cosmological context, comparing it to the galaxies around us. We then focussed on the chemistry and structure of the Milky Way bulge, featuring a review by Manuela Zoccali (PUC Chile). The final part, which focussed on dynamics, was kicked off with a review by Ortwin Gerhard (MPE). Each session had a number of interesting talks, including new results both observational (e.g. the study of the Milky Way analogue NGC4710 by Oscar Gonzalez and the APOGEE work of Melissa Ness) and theoretical (e.g. the new bulge formation simulations of Victor Debattista and the mass modelling of Chris Wegg). Given the timing of the meeting, on the cusp of the first Gaia data release, it was especially interesting to hear about the prospects of Gaia for studying the bulge, which was given by Laura Ruiz Dern on behalf of Carine Babusiaux (Observatoire de Paris).

More info about this special session may be found here.

Martin C. Smith (Shanghai Astronomical Observatory, China)
Melissa Ness (Max Planck Institute for Astronomy, Heidelberg, Germany)
Victor Debattista (University of Central Lancashire, UK)

During periods of intense solar activity, the solar wind is enhanced and geomagnetic storms produce auroras, disrupt radio transmissions, affect power grids, damage orbiting satellites, and can be dangerous to astronauts. By analogy, the magnetic activity of cool stars may be hazardous for the creation and development of life and is therefore of potential importance for habitability. With new observations and theoretical advances we are starting to understand the complex interactions between the planets and their host stars.

The meeting was organised during one day and it consisted of three sessions: solar and stellar magnetic activity, effect of the activity on (exo)planets, and long term evolution of activity and its effect on habitability. The first session consisted of invited talks on the solar dynamo (Simoniello) and the stellar magnetic activity (Hussain), and two contributed talks discussing observational and theoretical aspects of stellar activity. The second session was dedicated to the effect stellar and solar activity has on planets. It kicked off with an invited talk (Bourrier) followed by four contributed talks discussing the activity effects both on bodies in our Solar System and on exoplanets. The last session was started with an invited talk (Ribas) on long-term evolution of stellar activity and continued with three contributed talks and a short poster presentation. The talks were all of high quality and provoked many questions and comments from the audience.

The relatively small, but still a good sized audience of some 30 scientist, created a nice informal atmosphere that enabled very lively discussions. On the whole the meeting more than full-filled our expectations. The organisers would like to thank all the speakers and participants for making this a very fruitful Special Session. In addition, we would like to thank EWASS for making this meeting possible.

More info about this special session may be found here.

Heidi Korhonen (University of Copenhagen, Denmark)
Aline Vidotto (Trinity College Dublin, Ireland)

The FU Orionis objects (FUor) are long-studied examples of this phenomenon. FUors are believed to undergo accretion outbursts during which the accretion rate rapidly increases from typically 1e-7 to 1e-4 solar masses per year, and remains elevated over timescales of several decades or more. EXors, a loosely defined class of pre-main sequence stars, exhibit similar but shorter and repetitive outbursts, associated with lower accretion rates. The relationship between the two classes, and their relationship to the standard pre-main sequence evolutionary sequence, is an open question: do they form two distinct classes, are they triggered by the same physical mechanism, and do they occur in the same evolutionary phases? Over the past couple of decades, many theoretical and numerical models have been developed to explain the origin of FUor and EXor outbursts, and suggest that this phenomenon may be universal in star formation. In parallel, such accretion bursts have been detected at increasing rate, and each individual outburst is more carefully scrutinised and monitored across the electromagnetic spectrum.

The special session was dedicated to present and discuss our contemporary understanding of episodic accretion from the theoretical, numerical, and observational points of view, and to determine the most promising directions for this field of star formation in the near- and long-term. The special session featured 6 invited speakers (Shantana Basu, Neal J. Evans, Eduard Vorobyov, Caroline d'Angelo, Agnes Kosapl, Marc Audard) who gave overviews of the topic, and 6 additional contributed talks (Ruobing Dong, Patrick Hennebelle, Ben MacFarlane, Teresa Giannini, Christian Rab, Carlos Contreras). In addition, 6 short 3-min presentations were made by some participants of the session (Evgeni Semkov, Lionel Haemmerlé, Simone Antoniucci, Yuya Sakurai, Anthony Mercer, Peter Abraham). About 30-40 participants from many different countries attended the session.

The organizers warmly thank all speakers and participants for the successful meeting, and the EWASS 2016 organizers for the selection of this special session.

More info about this special session may be found here.

Marc Audard (University of Geneva, Switzerland)
Peter Abraham (Konkoly Observatory, Hungary)
Michael Dunham (Harvard-Smithsonian Center for Astrophysics, USA)
Joel Green (Space Telescope Science Institute, USA)
Nicolas Grosso (Observatoire de Strasbourg, France)
Kenji Hamaguchi (NASA/GSFC and University of Maryland Baltimore County, USA)
Joel Kastner (Rochester Institute of Technology, USA)
Agnes Kospal (Konkoly Observatory, Hungary)
Giuseppe Lodato (University of Milano, Italy)
Marina Romanova (Cornell University, USA)
Stephen L. Skinner (University of Colorado, Boulder, USA)
Eduard Vorobyov (University of Vienna, Austria)
Zhaohuan Zhu (Princeton University, USA)

With the construction of SKA1-MID in South Africa, there will be a great opportunity for collaborations between SKA and various VLBI networks in Europe, Asia, Australia, and the developing African VLBI Network. Our specific goals were to identify the VLBI science cases which benefit significantly from the great sensitivity of SKA1-MID, and to discuss the operating model for SKA-VLBI, as well as the roadmap for science exploration with global VLBI.

The three 1.5h sessions each consisted of an invited review, three contributed talks, and 15 minutes discussion. The three main topics were SKA-VLBI astrometry, Active Galactic Nuclei and wide field-of-view VLBI surveys, and explosive phenomena/transients. The number of participants of these sessions varied between 20-30, not bad considering the late timing of the SS10. We actually had lively discussion on the following three topics: the progress in VLBI astrometry and prospects for the SKA era, the role VLBI may play in SKA KSPs, and transient use cases for SKA-VLBI/triggering observations using SKA.

A highlight result that was presented during our special session was the stringent constraint on the proper motion of the first jetted tidal disruption event, from observations by the European VLBI Network (EVN). This was highlighted by the review speaker Imma Donnarumma (INAF); the actual work was done by Jun Yang et al. (Onsala Space Observatory), who could not be present in person. A press release can be found at the Joint Institute for VLBI ERIC webpage.

More info about this special session may be found here.

Zsolt Paragi (JIVE, Netherlands)
Cormac Reynolds (CSIRO, Australia)
Maria Rioja (ICRAR-CSIRO, Australia and OAN, Spain)
Mar Mezcua (Harvard, USA)
Huib van Langevelde (JIVE and Leiden University, Netherlands)
Leonid Gurvits (JIVE and Delft University, Netherlands)
Anna Bartkiewicz (Torun Centre for Astronomy, Poland)

Turbulence is a key player not only for the gas structure and the rate of star formation. It also impacts the gas thermodynamics as a heat source in the dissipation regions, the propagation of cosmic rays, the properties of dust grains and the gas chemistry. Turbulence has a strong influence on the transition between atomic and molecular hydrogen, the formation of hydrides and more generally the interstellar chemistry. Numerical simulations are now able to capture the multiphase nature of the ISM but cannot include all aspects. Discussions and exchanges between observers and theorists are therefore necessary to identify the challenges and diagnostic tools. The aims of this special session during EWASS 2016, was to discuss recent theoretical and observation results.

The invited and contributed presentations discussed the physics of turbulence in the interstellar medium in the Galaxy as well as in external galaxies, and the relation with the star formation rate at small and large scales. New observations of the bistable nature of the atomic gas were presented that highlight the need for a deep understanding of the heating processes. The couplings of the physical structure of the matter with the small scale processes was presented, with the emphasis put on the impact of turbulence on the formation and spatial distribution of the simple molecules CO and H2. The reactive ion CH+ was the focus of another presentation because this ion is one of the best tracers of the dissipation regions of the turbulence. The new perspectives on the structure and intensity of the magnetic field gained from the Planck Surveyor mission were presented. Individual contributions discussed the properties of the field in specific regions of the sky as probed by ground based polarimetry observations, and the information on the field fluctuations accessible from large scale surveys of the polarised synchrotron emission.

Molecular line intensities can be used as diagnostics of the physical processes. One key parameter for the coupling of the matter with the magnetic field is the ionisation fraction. Therefore, a presentation was dedicated to state of the art chemical models and the diagnostics of the cosmic ray ionisation rate from molecular ions abundances. Such diagnostics will soon be applicable to large scale maps of the interstellar medium, given the available sensitivity and instantaneous bandwidth. The presentation of the OrionB survey highlighted both the jump in information provided by such surveys, and the need for developing new analysis methods fitted to the combined spatial and spectral information.

The meeting was help in a friendly atmosphere, with excellent talks and stimulating discussions. The audience was mixed with senior researchers and more junior scientists and students. We appreciated the help of students for the setup of the presentations, which ensure the respect of the agenda in a smooth and timely way.

More info about this special session may be found here.

Maryvonne Gerin (LERMA, France)
Patrick Hennebelle (CEA, France)
Susanne Aalto (Chalmers University, Sweden)
Simon Glover (Heidelberg University, Germany)
Sergio Molinari (INAF, Italy)
Snezana Stanimirovic (University of Wisconsin, USA)