The Ionized Stellar Wind in Vela X-1 during Eclipse
Authors:
- Norbert S. SchulzNSNorbert S. Schulz
- Claude R. CanizaresCCClaude R. Canizares
- Julia C. LeeJLJulia C. Lee
- Masao SakoMSMasao Sako
- 1 January 2002
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 564 (1) , L21-L25
Abstract
We present a first analysis of a high resolution X-ray spectrum of the ionized stellar wind of Vela X-1 during eclipse. The data were obtained with the High Energy Transmission Grating Spectrometer onboard the Chandra X-ray Observatory. The spectrum is resolved into emission lines with fluxes between 0.02 and 1.04x10^4 ph/cm^2/s. We identify lines from a variety of charge states, including fluorescence lines from cold material, a warm photoionized wind. We can exclude signatures from collisionally ionized plasmas. For the first time we identify fluorescence lines from L-shell ions from lower Z elements. We also detect radiative recombination continua from a kT = 10 eV (1.2 x 10^5 K) photoionized optically thin gas. The fluorescence line fluxes infer the existence of optically thick and clumped matter within or outside the warm photoionized plasma.Comment: 4 pages, 2 figures, accepted by ApJ letterKeywords
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