Chemical Elements as Tracers of the Evolution of the Cosmos


CEMP Stars as Probes of First-Star Nucleosynthesis, the IMF, and Galactic Assembly (Working Group Meeting)
09 Sep, 2019 to 13 Sep, 2019 Geneva University, 30 quai Ernest Ansermet in Auditorium A100 Sciences II,

The beginning of the stellar era in the Universe is a singularly fascinating phase in the history of the Cosmos. The baryonic material filling the Universe at that time, having a composition inherited from Big Bang nucleosynthesis, has its physical characteristics modified by the very first stars. Indeed, the first stars will change the degree of ionized material in their vicinity, and, through their winds and/or supernova explosion, will inject energy, momentum, and newly-synthesized elements. Some pockets of gas, enriched by the first stars, will in turn form new stars, whose initial composition is inherited from the first nucleosynthetic events. These low-mass stars can live sufficiently long to be observed today in halo of the Galaxy, providing the opportunity to obtain information about the very high redshift Universe by the study of nearby stars. How did these processes happen? How were these processes different from similar ones occurring in the present Universe? What can they teach us about the infancy of the Universe during the reionization era? These are the questions that will be discussed during this workshop, questions that are particularly topical at a time when new facilities, such as SKA, JWST, and the next generation of extremely large telescopes have as one of their prime objectives to probe this very period. At present, observational constraints on these first stars are scarce and/or indirect. Important constraints come from observations of the elemental abundances of very, extremely, and ultra iron-poor stars that likely formed from the ejecta of the first stellar generations. Of course the full story can be complex, as some elements might be formed by more than one source, and others may be somewhat altered by in-situ processes that occurred in the star that is observed today. Nevertheless, through the accumulation of observational data, progress made in numerical simulations, and in our deeper understanding of the physical processes involved, a much more complete and detailed story can be told.

Lithium in the Universe: to Be or not to Be? (Working Group Meeting)
18 Nov, 2019 to 22 Nov, 2019 The Observatory of Rome, Monte Porzio Catone, Italy,

Among all the chemical species present in the Universe, lithium is unique for being the protagonist in several astrophysical contexts, spanning all epochs, from the Big Bang to the present day, and extending over distances from our Sun to remote regions in the Milky Way system and beyond. Lithium is currently at the centre of two highly debated mysteries that catch the attention of astrophysicists. The expected primordial value of 7Li is a factor of 3 higher than measured in warm halo dwarf stars. This discrepancy is normally referred to as the cosmological lithium problem. Since the present lithium abundance as measured in meteorites or in young stars is A(Li)=3.3, a Galactic source is required. The identification of such sources is referred to as the Galactic lithium problem.

ChETEC Working Group 3 Workshop 2019
27 Feb, 2019 09:40 AM to 01 Mar, 2019 01:00 PM National Center for Physical Sciences and Technology, Vilnius, Lithuania,

The main goal of the workshop is the preparation of two observing proposals aimed to investigate: (a) the origin and evolution of the r-process elements in the EMP stars; (b) the origin of multiple stellar populations (MPs) in the Galactic globular clusters (GGCs); and (c) to exchange ideas regarding the possible future observing proposals related to the study of EMP stars, as well as MPs in the GGCs. Several broader review talks will set up the stage for an in-depth discussions of the two observing proposals. Separate slots will be reserved for in-depth discussions to plan future observing proposals. The largest fraction of the workshop time will be devoted to hands-on activities for writing the two observing proposals that will be submitted during the Period 104 call for proposals at ESO (March 2019). The detailed workshop program is provided below.

ChETEC Working Group 3 Workshop 2018
14 Mar, 2018 09:30 AM to 16 Mar, 2018 05:00 PM Vilnius, Lithuania,

The aim of the meeting is to tackle the following questions: (a) the preparation of the observing proposal to investigate evolution of Eu and Ba in the EMP stars; (b) discuss and take the necessary actions for the preparation of the Nuclear Astrophysics Database (NAD); and (c) discuss and launch several science projects presented at the Keele meeting in October 2017. It is foreseen that the meeting will be heavily based on discussions and interactions. Several talks will set up the stage for an in-depth discussions, with at least 10-15 min foreseen for questions and discussion after each talk. Separate slots will be reserved for longer discussions to address various important issues in detail and, ultimately, to plan further steps and actions. The meeting program is available here:

ChETEC Code of Conduct for meeting

Every event related to ChETEC needs to make use of the following Code of conduct. It is the same a the JINA Code of Conduct, for which we gratefully acknowledge JINA.

Main Action Workshop
09 Oct, 2017 02:00 PM to 11 Oct, 2017 05:00 PM Keele,

MC meeting + WG workshops

Knowledge Hubs workshop + period 2 MC meeting
27 Jun, 2018 from 12:30 PM to 07:00 PM National Institute for Nuclear Physics - Gran Sasso National Laboratory,

During the workshop, we will review the "knowledge hubs" that we have assembled and discuss how we can improve them further. After the workshop, we will have our period(year) 2 MC meeting.