Victoria Wang '22

Powerful Winds from Hot Stars Mass-loss rate diagnostics on the X-ray emitting and absorbing winds of massive stars

Massive stars have winds, which are the continuous outflows of particles from the photospheres. Due to intrinsic instabilities in the winds, some fast-moving wind regions will collide with the slow-moving ones, generating supersonic shock waves and heating up the shocked gas to above a million degrees, the condition for X-ray emission. By analyzing the X-ray emission lines of new long Chandra grating observations taken during 2018 and 2019, we found a surprising 40% increase in zeta Puppis' mass-loss rate compared to data taken in Chandra's first observation cycle in 2000. And by modeling the broadband X-ray absorption features of 20 years of XMM-Newton observations, we confirmed a random but significant mass-loss rate variation of zeta Pup.