Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Electronic Refereed Journal Article (HTML)
· Full Refereed Journal Article (PDF/Postscript)
· arXiv e-print (arXiv:astro-ph/0112483)
· On-line Data
· References in the article
· Citations to the Article (22) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (8)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Variability of the X-Ray P Cygni Line Profiles from Circinus X-1 near Zero Phase
Authors:
Schulz, N. S.; Brandt, W. N.
Affiliation:
AA(Center for Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139.), AB(Department of Astronomy and Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802.)
Publication:
The Astrophysical Journal, Volume 572, Issue 2, pp. 971-983. (ApJ Homepage)
Publication Date:
06/2002
Origin:
UCP
ApJ Keywords:
Accretion, Accretion Disks, Stars: Binaries: Close, Stars: Individual: Constellation Name: Circinus X-1, Stars: Neutron, Techniques: Spectroscopic, X-Rays: Stars
DOI:
10.1086/340369
Bibliographic Code:
2002ApJ...572..971S

Abstract

The luminous X-ray binary Circinus X-1 has been observed twice near zero orbital phase using the High-Energy Transmission Grating Spectrometer (HETGS) on board Chandra. The source was in a high-flux state during a flare for the first observation, and it was in a low-flux state during a dip for the second. Spectra from both flux states show clear P Cygni lines, predominantly from H-like and He-like ion species. These indicate the presence of a high-velocity outflow from the Cir X-1 system, which we interpret as an equatorial accretion-disk wind, and from the blueshifted resonance absorption lines we determine outflow velocities of 200-1900 km s-1 with no clear velocity differences between the two flux states. The line strengths and profiles, however, are strongly variable both between the two observations as well as within the individual observations. We characterize this variability and suggest that it is due to both changes in the amount of absorbing material along the line of sight as well as changes in the ionization level of the wind. We also refine constraints on the accretion-disk wind model using improved plasma diagnostics such as the He-like Mg XI triplet, and we consider the possibility that the X-ray absorption features seen from superluminal jet sources can generally be explained via high-velocity outflows.
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints