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Accretion Disk Spectra of the Brightest Ultra-luminous X-ray Source in M82

Feng Yuan·Ronald E. Taam R. Misra·Xue-Bing Wu·Yongquan Xue
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Abstract

Emission spectra of hot accretion disks characteristic of advection dominated accretion flow (ADAF) models are investigated for comparison with the brightest ultra-luminous source, X-1, in the galaxy M82. If the spectral state of the source is similar to the low luminosity hard state of stellar mass black holes in our Galaxy, a fit to the {\it Chandra} X-ray spectrum and constraints from the radio and infrared upper limits, require a black hole mass in the range of $9 \times 10^4 - 5 \times 10^5 \msun$. Lower black hole masses ($\la 10^4 \msun$) are possible if M82 X-1 corresponds to the high luminosity hard state of Galactic black hole X-ray binary sources. Both of these spectrally degenerate hot accretion disk solutions lead to an intermediate mass black hole interpretation for M82 X-1. Since these solutions have different spectral variability with X-ray luminosity and predict different infrared emission, they can be distinguished by future off axis {\it Chandra} observations or simultaneous sensitive infrared detections.

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Feng Yuan, Ronald E. Taam R. Misra, Xue-Bing Wu, Yongquan Xue. 2006-11-30. Accretion Disk Spectra of the Brightest Ultra-luminous X-ray Source in M82. https://doi.org/10.1086/511301

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