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Broad P Cygni X-ray Lines from Circinus X-1

N. S. Schulz·W. N. Brandt
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Abstract

Chandra High Energy Transmission Grating Spectrometer (HETGS) observations of the extremely luminous and violent X-ray binary Cir X-1 reveal many X-ray emission lines showing broad P Cygni profiles. These are from H-like and He-like ions of Ne, Mg, Si, S, Ar, and Fe. The lines originate in a high-velocity (up to 2000 km s^-1) outflow, which may be an accretion disk wind. Cir X-1 has a radio jet, and during some periastron passages of the neutron star (orbital phase = 0.0), it flares at radio, infrared and X-ray wavelengths. The X-ray P Cygni profiles were observed during this phase, where we also expect the strongest mass transfer from the companion star. We present new results on the time variability of the P Cygni profiles and discuss their general importance.

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N. S. Schulz, W. N. Brandt. 2000-12-01. Broad P Cygni X-ray Lines from Circinus X-1. https://arxiv.org/abs/astro-ph/0012030

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