Stellar evolution leads to a rich variety of transient phenomena. The host galaxies of transients - and their environments within or around their hosts - are a valuable source of information about transient progenitors. Likewise, transients can be used as a tool to understand the galaxies themselves, with applications from cosmology to understanding galaxy chemical enrichment over cosmic time. The full promise of transient host studies can only be realised by advancing our understanding of, and coupling together, (binary) stellar populations and the evolution and properties of the galaxies they inhabit. This session will explore the two-way interplay between the study of electromagnetic (EM) and gravitational wave (GW) transients arising from (binary) stellar evolution, and the galaxies that host them. The fields of EM and GW transients are converging: host galaxies will play a key role in full convergence.

Programme

The session goals and topics to be discussed are as follows:

1. Bring together communities studying the hosts of extragalactic transients with a view to constraining progenitor models, including supernovae of all kinds, gamma-ray bursts (GRBs, core-collapse and compact merger), fast X-ray transients, fast radio bursts (FRBs) and more. Sharing of techniques for host galaxy modelling and progenitor inference.

2. Discuss the latest advances in using transients and their hosts as tools: including the role that host galaxies play in supernova Ia and dark siren cosmology, the use of high-redshift GRBs as probes of the epoch of reionisation, and the insight that transients such as FRBs and GRBs provide on spatial scales otherwise inaccessible to observations in extragalactic environments.

3. Look forward to the advances that will be possible with new and next generation facilities, from Rubin and Euclid to LIGO/VIRGO/KAGRA O5 and third generation gravitational wave observatories, and discuss how we should best prepare for their exploitation.

4. Stimulate discussion around how the interplay of galaxy and stellar population evolution affects our predictions for transients rates and environments. For example, what impact do galaxy mergers have on transients with delay times similar to or longer than these timescales?

5. Raise awareness of existing stellar population synthesis codes, compare and contrast their differences and consistencies. Gauge the current effectiveness of stellar evolutionary models/codes against observed stellar populations, with a focus on binaries.

Invited speakers

TO BE ANNOUNCED

Scientific organisers

Ashley Chrimes (ESA-ESTEC), Soheb Mandhai (University of Manchester), Kendall Ackley (University of Warwick), Sumedha Biswas (Radboud University), Anne Inkenhaag (University of Bath), Heloise Stevance (University of Oxford), Jonathan Quirola Vasquez (Radboud University), Patricia Schady (University of Bath)

Contact

Ashley Chrimes: ashley.chrimes @ esa.int