| Autor: |
Cropper, Mark, Copperwheat, Christopher, Wu, Kinwah, Soria, Roberto |
| Rok vydání: |
2007 |
| Předmět: |
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| Zdroj: |
Black Holes: From Stars to Galaxies - Across the Range of Masses, International Astronomical Union. Symposium no. 238, held 21-25 August, 2006 in Prague, Czech Republic, S238, #10 |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1017/S1743921307005078 |
| Popis: |
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 admissable. 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. |
| Databáze: |
arXiv |
| Externí odkaz: |
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