Complete and Simultaneous Spectral Observations of the Black Hole X-Ray Nova XTE J1118+480
Abstract
The X-ray nova XTE J1118+480 suffers minimal extinction (b=62deg) and therefore represents an outstanding opportunity for multiwavelength studies. Hynes et al. conducted the first such study, which was centered on 2000 April 8 using UKIRT, EUVE, HST, and RXTE. On 2000 April 18, the Chandra X-Ray Observatory obtained data coincident with a second set of observations using all of these same observatories. A 30 ks grating observation using Chandra yielded a spectrum with high resolution and sensitivity covering the range 0.24-7 keV. Our near-simultaneous observations cover ~80% of the electromagnetic spectrum from the infrared to hard X-rays. The UV/X-ray spectrum of XTE J1118+480 consists of two principal components. The first of these is an ~24 eV thermal component that is caused by an accretion disk with a large inner disk radius: >~35R Schw. The second is a quasi power-law component that was recorded with complete spectral coverage from 0.4 to 160 keV. A model for this two-component spectrum is presented in a companion paper by Esin et al.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 2001
- DOI:
- 10.1086/321449
- arXiv:
- arXiv:astro-ph/0103051
- Bibcode:
- 2001ApJ...555..477M
- Keywords:
-
- Accretion;
- Accretion Disks;
- Stars: Binaries: Close;
- Stars: Individual: Alphanumeric: XTE J1118+480;
- Ultraviolet: Stars;
- X-Rays: Stars;
- Astrophysics
- E-Print:
- 19 pages, 4 figures, resubmitted to ApJ on March 2, 2001