Spitzer IRAC observations of IR excess in Holmberg IX X-1: A circumbinary disk or a variable jet?

Abstract

We present Spitzer Infrared Array Camera (IRAC) photometric observations of the Ultra-luminous X-ray Source (ULX, X-1) in Holmberg IX. We construct a spectral energy distribution (SED) for Holmberg IX X-1 based on published optical, UV and X-ray data combined with the IR data from this analysis. We modeled the X-ray and optical data with disk and stellar models, however we find a clear IR excess in the ULX SED that cannot be explained by fits or extrapolations of any of these models. Instead, further analysis suggests that the IR excess results either from dust emission, possibly from a circumbinary disk or from a variable jet.

25 pages, 2 figures, accepted by ApJ

References in corpus (15)

• An Ultraluminous X-ray Source Powered by An Accreting Neutron Star
• Super-critically accreting stellar-mass black holes as ultraluminous X-ray sources
• XMM-Newton observations of the brightest Ultraluminous X-ray sources
• A mass of less than 15 solar masses for the black hole in an ultraluminous X-ray source
• A spectral-timing model for ULXs in the super-critical regime
• X-ray irradiation in XTE J1817-330 and the inner radius of the truncated disc in the hard state
• Reprocessing of X-rays in the outer accretion disc of the black hole binary XTE J1817--330
• Spectroscopy of Optical Counterparts of Ultraluminous X-ray Sources
• Testing the Paradigm that Ultraluminous X-ray Sources as a Class Represent Accreting Intermediate-Mass Black Holes
• Optical Properties of the Ultraluminous X-ray Source Holmberg IX X-1 and its Stellar Environment
• Accretion Rates and Beaming in Ultraluminous X-ray Sources
• Optical Counterparts of Ultra Luminous X-ray Sources
• The evolved circumbinary disk of AC Her: a radiative transfer, interferometric and mineralogical study
• Irradiated, colour-temperature-corrected accretion discs in ultraluminous X-ray sources
• The circumbinary disk of HD 98800 B: Evidence for disk warping

Cited by in corpus (1)

• Uncovering Red and Dusty Ultraluminous X-ray Sources with Spitzer