Μάθημα : Ενημέρωση φοιτητών κατεύθυνσης Αστροφυσικής

Speaker: Prof. Bret Lehmer, University of Arkansas, USA

Title: The Critical Role of High Resolution X-ray Constraints on Stellar Population Evolution

Abstract: Over the last 26 years, we have enjoyed unique resolved X-ray images of galaxies of all morphological types thanks to the Chandra and XMM-Newton missions. X-ray emission from normal galaxies (not dominated by an AGN) has significant contributions from X-ray binary (XRB) populations, hot gas, and supernovae (SNe). XRBs probe the demographics of compact objects, close binaries, and massive stars, as well as the physics and environmental impact of accretion onto compact objects. Hot gas and SNe trace stellar feedback into the interstellar medium (ISM). 

I will discuss how the vast expansion of new multiwavelength facilities and the accumulation of X-ray observations in the archive have led to a clearer picture of how X-ray populations trace star-formation histories, metallicities, and dynamical environments of their host stellar populations. I will highlight first X-ray results from ongoing Legacy/Treasury programs that are part of the Physics at High Angular resolution in Nearby GalaxieS (PHANGS) collaboration, which is providing unprecedented views of 74 southern nearby (D ~ 3-30 Mpc) star-forming galaxies from Chandra, ALMA, HST, JWST, VLT/MUSE, and several other observatories. These data will continue to be used to make headway in several highly active areas of astrophysics, complementing our understanding of stellar evolution models, ISM ionization in low-metallicity and high-redshift galaxies, binary-related phenomena (e.g., GRBs, SNe, gravitational wave sources, etc.), and heating of the intergalactic medium during the epoch of heating at z > 8.