Optical Sources Near the Bright X-Ray Source in NGC 1073

Abstract

New HST observations show that the bright X-ray source in the face-on spiral galaxy NGC 1073 is located near a ring of recent star formation with an age of 8-16 Myr. This strengthens the association of X-ray sources in spiral galaxies emitting near or above the Eddington limit for a 20 solar mass black hole with recent star formation events. Two candidate optical counterparts of the X-ray source are found. The X-ray to optical flux ratios of both are consistent with those of low-mass X-ray binaries and higher than most high-mass X-ray binaries, suggesting that reprocessing of X-rays contributes to the optical light. The optical magnitude and color of one candidate is consistent with that predicted for an X-ray binary with an initial donor mass of 6-8 solar masses. However, the same X-ray binary evolution model underestimates the X-ray luminosity. An X-ray source list for the field is presented which includes detections of the nucleus of NGC 1073, three quasars, and an M3e brown dwarf star with high proper motion.

to appear in ApJ, 12 pages, several color figures

References in corpus (4)

• High Resolution Imaging of the HeII lambda 4686 Emission Line Nebula Associated with the Ultraluminous X-Ray Source in Holmberg II
• Stellar Mass Black Hole Binaries as ULXs
• The optical counterpart of an Ultra-luminous X-Ray Source in NGC 5204
• The star-forming environment of a ULX in NGC 4559: an optical study

Cited by in corpus (16)

• Ultraluminous X-ray Sources in the Chandra and XMM-Newton Era
• Low metallicity natal environments and black hole masses in Ultraluminous X-ray Sources
• A 62 Day X-Ray Periodicity and an X-Ray Flare from the Ultraluminous X-Ray Source in M82
• Optical emission of the ultraluminous X-ray source NGC 5408 X-1: donor star or irradiated accretion disk?
• Optical emission from massive donors in ULX binary systems
• A Radio Nebula Surrounding the Ultra-luminous X-ray Source in NGC 5408
• Optical Properties of the Ultraluminous X-ray Source Holmberg IX X-1 and its Stellar Environment
• Optical Counterpart of the Ultraluminous X-ray Source IC 342 X-1
• X-ray and optical variability of the ultraluminous X-ray source NGC 1313 X-2
• Toward a Clean Sample of Ultra-Luminous X-ray Sources
• Evolution of the X-Ray Jets from 4U 1755--33
• Chandra and HST Observations of the Supersoft ULX in NGC 247: Candidate for Standard Disk Emission
• Optical Counterparts of ULXs and Their Host Environments in NGC 4490/4485
• X-ray spectral and optical properties of a ULX in NGC 4258 (M106)
• Optical Counterparts of an Ultraluminous X-Ray Source X-1 in NGC 2500
• Discovery of a Large Population of Ultraluminous X-ray Sources in the Bulge-less Galaxies NGC 337 and ESO 501-23