2000/12/01 by N. S. Schulz, Norbert S. Schulz, W. N. Brandt +2
Engineering · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #FOS: Physical sciences #Particle Accelerators and Free-Electron Lasers #Particle accelerators and beam dynamics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0012030
8 pages, 3 figures, to be published in "Astronomy 2000", eds. R. Giaconni, Luigi Stella, & Salvatore Serio, ASP Conference Series, 2000
arxiv created 2000/12/01 · openalex publication_date 2000/12/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.