Journal article
THE NATURE OF THE UV/OPTICAL EMISSION OF THE ULTRALUMINOUS X-RAY SOURCE IN HOLMBERG II
The Astrophysical journal, Vol.750(2), pp.1-7
2012
DOI: 10.1088/0004-637X/750/2/110
Abstract
We report on UV and X-ray spectroscopy and broadband optical observations of the ultraluminous X-ray source in HolmbergII. Fitting various stellar spectral models to the combined, non-simultaneous data set, we find that normal metallicity stellar spectra are ruled out by the data, while low-metallicity, Z = 0.1 Ż, late O-star spectra provide marginally acceptable fits, if we allow for the fact that X-ray ionization from the compact object may reduce or eliminate UV absorption/emission lines from the stellar wind. By contrast, an irradiated disk model fits both UV and optical data with χ2/dof = 175.9/178, and matches the nebular extinction with a reddening of E(B - V) = 0.05+0.05- 0.04. These results suggest that the UV/optical flux of HolmbergII X-1 may be dominated by X-ray irradiated disk emission. © 2012. The American Astronomical Society. All rights reserved.
Details
- Title: Subtitle
- THE NATURE OF THE UV/OPTICAL EMISSION OF THE ULTRALUMINOUS X-RAY SOURCE IN HOLMBERG II
- Creators
- LIAN Tao - Tsinghua UniversityPhilip Kaaret - University of IowaHUA Feng - Tsinghua UniversityFabien Grise - University of Iowa
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.750(2), pp.1-7
- DOI
- 10.1088/0004-637X/750/2/110
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Publisher
- Institute of Physics (IOP)
- Language
- English
- Date published
- 2012
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199798002771
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