Far Ultraviolet Spectroscopic Explorer Spectra of the Black Hole Binary LMC X-3
Abstract
Far-ultraviolet spectra of LMC X-3 were taken covering photometric phases 0.47-0.74 in the 1.7 day orbital period of the black hole binary (phase zero being superior conjunction of the X-ray source). The continuum is faint and flat but appears to vary significantly during the observations. Concurrent RXTE/ASM observations show the system was in its most luminous X-ray state during the Far Ultraviolet Spectroscopic Explorer (FUSE) observations. The far-UV spectrum contains strong terrestrial airglow emission lines, while the only stellar lines clearly present are emissions from the O VI resonance doublet. Their flux does not change significantly during the FUSE observations. These lines are modeled as two asymmetric profiles, including the local ISM absorptions due to C II and possibly O VI. Velocity variations of O VI emission are consistent with the orbital velocity of the black hole and provide a new constraint on its mass.
Based on observations made with the NASA-CNES-CSA Far Ultraviolet Spectroscopic Explorer. FUSE is operated for NASA by Johns Hopkins University under NASA contract NAS 5-3298.- Publication:
-
The Astronomical Journal
- Pub Date:
- November 2003
- DOI:
- 10.1086/378606
- arXiv:
- arXiv:astro-ph/0308482
- Bibcode:
- 2003AJ....126.2368H
- Keywords:
-
- Stars: Individual: Alphanumeric: LMC X-3--;
- Astrophysics
- E-Print:
- 12 pages including 1 table, 4 diagrams To appear in AJ