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  • Chandra spectral measurements of the O supergiant ζ Puppis indicate a surprising increase in the wind mass-loss rate over 18 yr
Title: Chandra spectral measurements of the O supergiant ζ Puppis indicate a surprising increase in the wind mass-loss rate over 18 yr
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$${\mathrm{M_{\odot }~{\mathrm{y}r^{-1}}}}$$, 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.  more » « less
Award ID(s):
1950797
PAR ID:
10312640
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
499
Issue:
4
ISSN:
0035-8711
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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