Hostname: page-component-7c8c6479df-995ml Total loading time: 0 Render date: 2024-03-29T00:07:47.679Z Has data issue: false hasContentIssue false

On the nature of ultra-luminous X-ray sources from optical/IR measurements

Published online by Cambridge University Press:  01 August 2006

Mark Cropper
Affiliation:
Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
Chris Copperwheat
Affiliation:
Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
Roberto Soria
Affiliation:
Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK Centre for Astrophysics, Harvard Smithsonian Astrophysical Observatory, 60 Garden St, Cambridge, MA 02138, USA
Kinwah Wu
Affiliation:
Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present a model for the prediction of the optical/infra-red emission from ULXs. In the model, ULXs are binary systems with accretion taking place through Roche lobe overflow. We show that irradiation effects and presence of an accretion disk significantly modify the optical/infrared flux compared to single stars, and also that the system orientation is important. We include additional constraints from the mass transfer rate to constrain the parameters of the donor star, and to a lesser extent the mass of the BH. We apply the model to fit photometric data for several ULX counterparts. We find that most donor stars are of spectral type B and are older and less massive than reported elsewhere, but that no late-type donors are admissible. The degeneracy of the acceptable parameter space will be significantly reduced with observations over a wider spectral range, and if time-resolved data become available.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2007

References

Begelman, M. C. 2002, ApJ, 568, L97CrossRefGoogle Scholar
Colbert, E. J. M. & Mushotzky, R. F. 1999, AJ, 519, 89CrossRefGoogle Scholar
Copperwheat, C., Cropper, M., Soria, R. & Wu, K. 2005, MNRAS, 362, 79CrossRefGoogle Scholar
Copperwheat, C., Cropper, M., Soria, R. & Wu, K. 2006, MNRAS, submittedGoogle Scholar
Copperwheat, C. 2007, PhD Thesis, University of London, submittedGoogle Scholar
Fabbiano, G. 2004, Rev. Mex. A. A. (Serie de Conferencias), 20, 46Google Scholar
King, A. R. 2002, MNRAS, 335, L13CrossRefGoogle Scholar
Lejeune, T. & Schaerer, D. 2001, A&A, 366, 538Google Scholar
Milne, E. A. 1926, MNRAS 87, 43CrossRefGoogle Scholar
Phillips, S. N. & Podsiadlowski, P. 2002, MNRAS 337, 431CrossRefGoogle Scholar
Ritter, H. 1988, A&A 202, 93Google Scholar
Soria, R. S. & Kuncic, Z. 2006, Adv. Space. Res. (Cospar special issue) submittedGoogle Scholar
Wu, K. 1997 Accretion Phenomena and Related Outflows; IAU Colloquium 163., ASP Conference Series Vol. 121; ed. Wickramasinghe, D. T.Bicknell, G. V. & Ferrario, L. (1997), p.283Google Scholar
Wu, K., Soria, R., Hunstead, R. W. & Johnston, H. M. 2001, MNRAS 320, 177CrossRefGoogle Scholar