HE Astrophysics Seminar | Ylva Götberg (Carnegie observatories)

Date: 
Mon, 12/04/2021 17:00 to 18:00
Location: 
https://huji.zoom.us/j/89109523146?pwd=Q1Z0b2xpTHRiZ1hla2RSRDViRmNwdz09

Title: Stars stripped in binaries: from cosmic reionization to gravitational waves

Abstract: Most massive stars spend their lives in so close orbit with a companion star that severe mass exchange or even coalescence is inevitable as the stars evolve and swell. A third of massive stars are thus stripped of their fluffy, hydrogen-rich envelopes, leaving the compact helium core exposed. These stripped stars are so hot that most of their radiation is emitted in the ionizing regime. Using evolutionary and spectral models of stripped stars, I will show how they sometimes dominate the ionizing emission from full stellar populations and even significantly contribute to cosmic reionization. With their hard ionizing spectra, stripped stars possibly leave observable traces, for example in the nebular spectrum of distant galaxies. 
Apart from being ionizing sources, stripped stars are also interesting to consider as gravitational wave emitters. Creating a population model, we predict that several stripped stars orbiting compact objects will be detectable by LISA. 

***HE seminar recordings***

~~~~~~~~~~~~~~~~~~~~~~

Join Zoom Meeting

https://huji.zoom.us/j/89109523146?pwd=Q1Z0b2xpTHRiZ1hla2RSRDViRmNwdz09


Meeting ID: 891 0952 3146

Passcode: 485033