BEGIN:VCALENDAR VERSION:2.0 PRODID:-//ZContent.net//ZapCalLib 1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT DTSTART;TZID=Atlantic/Canary:20230620T123000 DTEND;TZID=Atlantic/Canary:20230620T133000 UID:iactalks-1690 X-WR-CALNAME: IAC Talks: Open Astronomy Seminars X-ORIGINAL-URL: /iactalks/Talks/view/1690 CREATED:2023-06-20T12:30:00+01:00 X-WR-CALDESC: IAC Talks upcomming talks SUMMARY:The evolution and outcomes of the first massive stars in the Univer se DESCRIPTION:The evolution and outcomes of the first massive stars in the Un iverse\nGuglielmo Volpato\n\nExtremely metal-poor or zero-metallicity very massive stars, with initial mass in the range 100 ≲ Mi/M⊙ ≲ 1000, h ave a broad astrophysical impact. Understanding how these population III s tars evolve and die has implications for several key questions, including the nature of energetic transients such as pair-instability supernovæ ; and gamma-ray bursts, the source of extreme ionizing UV-radiation fields at high redshifts, the earliest chemical enrichment of their host galaxie s and the rates of gravitational-wave emission from merging black holes am ong others. There are not many models in literature that follow the e volution of these population III stars, and even less so that reach the ph ases where the production of electron-positron pairs alter the stability o f the whole star. We present new evolutionary models of very massive primordial stars, with initial masses ranging from 100 M☉ to 1000 M☉, that extend from the main sequence until the onset of dynamical instabilit y. We focus on the final outcome of the models and associated compact remn ants. Stars that avoid the pair-instability supernova channel, should prod uce black holes with masses ranging from ~ 40 M☉ to ~ 1000 M☉. In part icular, stars with initial masses of about 100 M☉ could leave black hole s of ≃ 85-90 M☉, values consistent with the estimated primary black ho le mass of the GW190521 merger event. Overall, these results may contribut e to explain future data from next-generation gravitational-wave detectors , such as the Einstein Telescope and Cosmic Explorer, which will have acce ss to as-yet unexplored BH mass range of ~ 10^2-10^4 M☉ in the early uni verse. END:VEVENT END:VCALENDAR