Constraining the irradiated disk and the nature of the companion star in an ultraluminous X-ray source
Abstract
Previous HST observations of the ultraluminous X-ray source Holmberg IX X-1 show that its optical emission may be dominated at short wavelengths by an irradiated accretion disk and at long wavelengths by a late-type {super}giant star which would be the donor star in the system. This makes of Holmberg IX X-1 one of the few ULXs where we have a direct, observational hint about the presence of a companion star. We propose X-ray and UV to NIR observations with Chandra and HST/WFC3. The X-ray spectrum will be essential at modeling the disk emission and, combined with UV/optical measurements, will allow us to constrain the irradiation in the disk. Longer wavelengths will enable us to definitely identify the red excess emission as coming from the donor star or from some structure from the disk.
- Publication:
-
HST Proposal
- Pub Date:
- October 2011
- Bibcode:
- 2011hst..prop12747G