Book Non-Fellow In-person or Online SDM Ticket
Book Fellow In-Person or Online SDM Ticket
Recent spectroscopic observations of distant galaxies from the James Webb Space Telescope (JWST) have posed new questions about the nature of stellar populations. The extreme emission line equivalent widths and ratios, anomalous chemical enrichment patterns (e.g. extreme N/O and C/O ratios), unexpected shapes of the UV/optical continuum, the presence of a strong inverse Balmer break (or “Balmer jump”) features, and the presence of “P-Cygni” and other broad-line features tracing massive star winds (or active galactic nuclei) have all pointed towards the outsized impact of massive, metal poor stars. From a theoretical point of view, there are several competing explanations about these features, including extremely high gas densities, hard ionising spectra from hot stars, and the presence of very massive stars (>100 Msun) or even super massive stars (>1000 Msun).
Observations of the chemical and ionisation properties of high redshift galaxies have also been interpreted as evidence for a “top-heavy” IMF in some extreme systems. Although such top heavy IMFs are generally not seen in star formation events at low redshift, studies of early type galaxies have highlighted that many of these systems, predicted to have formed in extreme events at early cosmic times, also show IMF variations. IMF variations such as these have strong implications on the physics of star-formation in early galaxies and the interpretation of early JWST observations, including the presence of extremely bright galaxies formed within the first few 100 million years after the Big Bang.
This RAS Specialist Meeting will bring together theorists and observers working across high and low redshift observations of these extreme systems, providing a platform to address these critical open questions.
Timetable:
10:00 - 10:30 Welcome/Coffee
10:30 - 13:00 Morning Session
13:00 - 14:00 Lunch
14:00 - 15:30 Afternoon Session
15:30 - 16:00 Discussion/Tea
16:00 - 17:00 RAS Monthly A&G Highlights meeting
Abstract submission: https://docs.google.com/forms/d/e/1FAIpQLScYu1z-DFQPXT0jkpr9xtl-DRjiv0Oiz4wT6b_PCt0UPFKjkg/viewform?usp=dialog
Abstract submission deadline: 10 February 2025