ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR

Torrejon JM, Schulz NS, Nowak MA, Oskinova L, Rodes-Roca JJ, Shenar T, Wilms J (2015)

Publication Status: Published

Publication Type: Journal article

Publication year: 2015

Journal

Astrophysical Journal American Astronomical Society

Publisher: American Astronomical Society

Book Volume: 810

DOI: 10.1088/0004-637X/810/2/102

Abstract

We present an analysis of a 78 ks Chandra high-energy transmission gratings observation of the B0I star QV Nor, the massive donor of the wind-accreting pulsar 4U1538-52. The neutron star (NS) orbits its companion in a very close orbit (r < 1.4R(*), in units of the stellar radii), thereby allowing probing of the innermost wind regions. The flux of the Fe K alpha line during eclipse reduces to only similar to 30% of the flux measured out of eclipse. This indicates that the majority of Fe fluorescence must be produced in regions close to the NS, at distances smaller than 1R(*) from its surface. The fact that the flux of the continuum decreases to only similar to 3% during eclipse allows for a high contrast of the Fe Ka line fluorescence during eclipse. The line is not resolved and centered at lambda = 1.9368(-0.0018)(+0.0032) angstrom. From the inferred plasma speed limit of v < c Delta lambda/lambda < 800 km s(-1) and range of ionization parameters of log xi =[-1, 2], together with the stellar density profile, we constrain the location of the cold, dense material in the stellar wind of QV Nor using simple geometrical considerations. We then use the Fe K alpha line fluorescence as a tracer of wind clumps and determine that these clumps in the stellar wind of QV Nor (B0I) must already be present at radii r < 1.25R(*), close to the photosphere of the star.

Authors with CRIS profile

Jörn Wilms Professur für Astronomie und Astrophysik

Involved external institutions

University of Alicante / Universidad de Alicante / Universitat d'Alacant ES Spain (ES) Massachusetts Institute of Technology (MIT) US United States (USA) (US) Universität Potsdam DE Germany (DE)

How to cite

APA:

Torrejon, J.M., Schulz, N.S., Nowak, M.A., Oskinova, L., Rodes-Roca, J.J., Shenar, T., & Wilms, J. (2015). ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR. Astrophysical Journal, 810. https://doi.org/10.1088/0004-637X/810/2/102

MLA:

Torrejon, J. M., et al. "ON THE RADIAL ONSET OF CLUMPING IN THE WIND OF THE B0I MASSIVE STAR QV NOR." Astrophysical Journal 810 (2015).

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