Title

X-Ray Spectroscopy Of The O2 If* Star Hd 93129a

Document Type

Conference Proceeding

Publication Date

2012

Published In

Four Decades Of Research On Massive Stars: Proceedings Of A Scientific Meeting In Honor Of Anthony F.J. Moffat

Abstract

The O2 If* star, HD 93129A, is among the earliest in the Galaxy and has one of the strongest winds of any 0 star. In this paper, we show that its hard and strong X-ray emission can be understood in terms of the standard embedded wind shock paradigm for effectively single, hot, massive stars. Wind attenuation of the intrinsically soft X-ray emission is an important effect, which explains the hardness of the observed X-rays. We measure the degree of wind absorption in two different ways in order to derive a mass-loss rate of roughly 6 x 10(-6) M-circle dot yr(-1). This value is consistent with the observed H alpha line if a clumping factor of f(cl) = 12 is assumed.

Published By

Astronomical Society of the Pacific

Editor(s)

L. Drissen, C. Robert, N. St. Louis, and A. F.J. Moffat, eds.

Conference

Four Decades Of Research On Massive Stars: A Scientific Meeting In Honor Of Anthony F.J. Moffat

Conference Dates

July 11-15, 2011

Conference Location

Auberge Lac Taureau, St-Michel-des-Saints, Québec, Canada