Document Type
Article
Publication Date
12-1-2020
Published In
Monthly Notices Of The Royal Astronomical Society
Abstract
New long Chandra grating observations of the O supergiant ζ Pup show not only a brightening of the X-ray emission line flux of 13 per cent in the 18 yr since Chandra’s first observing cycle, but also clear evidence – at more than 4σ significance – of increased wind absorption signatures in its Doppler-broadened line profiles. We demonstrate this with non-parametric analysis of the profiles as well as Gaussian fitting and then use line-profile model fitting to derive a mass-loss rate of 2.47 ± 0.09 × 10−6[Math Processing Error], which is a 40 per cent increase over the value obtained from the cycle 1 data. The increase in the individual emission line fluxes is greater for short-wavelength lines than long-wavelength lines, as would be expected if a uniform increase in line emission is accompanied by an increase in the wavelength-dependent absorption by the cold wind in which the shock-heated plasma is embedded.
Keywords
radiative transfer, stars: early-type, stars individual: ζ Puppis, stars: massive, stars: mass-loss, stars: winds, outflows, X-rays: stars
Recommended Citation
David H. Cohen et al.
(2020).
"Chandra Spectral Measurements Of The O Supergiant ζ Puppis Indicate A Surprising Increase In The Wind Mass-Loss Rate Over 18 Yr".
Monthly Notices Of The Royal Astronomical Society.
Volume 499,
Issue 4.
6044-6052.
DOI: 10.1093/mnras/staa3124
https://works.swarthmore.edu/fac-physics/434
Comments
This article has been published in Monthly Notices Of The Royal Astronomical Society. © 2020 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.