Optical Counterparts of Ultra Luminous X-ray Sources

Abstract

We present optical identification and characterization of counterparts of four objects previously catalogued as ultra-luminous X-ray sources. The objects were selected from the Colbert & Ptak (2002) catalogue. The optical counterparts are identified as point-like objects with magnitudes in the range \~17-19. The optical spectra of three of the sources (IXO 32, 37 and 40) show the presence of emission lines typical of quasars. The position of these lines allows a precise estimation of their redshifts (2.769, 0.567 and 0.789 for IXO 32, 37 and 40 respectively). The fourth X-ray source, IXO35, is associated with a red object that has a spectrum typical of an M star in our Galaxy. These identifications are useful for building clean samples of ULX sources, selecting suitable targets for future observations and performing statistical studies on the different populations of X-ray sources.

arXiv comment13 pages, 5 figures, accepted for publication in ApJL

References in corpus (23)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Ultraluminous X-Ray Sources in External Galaxies
• Characterization of M,L and T dwarfs in the Sloan Digital Sky Survey
• The Ultra-Luminous X-ray Source Population from the Chandra Archive of Galaxies
• NEXXUS: A comprehensive ROSAT survey of coronal X-ray emission among nearby solar-like stars
• Population X: Are the super-Eddington X-ray sources beamed jets in microblazars or intermediate mass black holes?
• A Catalog of Candidate Intermediate-luminosity X-ray Objects
• The X-ray Globular Cluster Population in NGC 1399
• Ultra-luminous X-ray Sources in nearby galaxies from ROSAT HRI observations I. data analysis
• Non-Nuclear Hyper/Ultraluminous X-Ray Sources in the Starbursting Cartwheel Ring Galaxy
• The optical counterpart of an Ultra-luminous X-Ray Source in NGC 5204
• The Lack of Very Ultraluminous X-ray Sources in Early-type Galaxies
• The unusual supernova remnant surrounding the ultraluminous X-ray source IC 342 X-1
• The identification of an optical counterpart to the super-Eddington X-ray source, NGC 5204 X-1
• Ultraluminous X-ray Source 1E 0953.8+6918 (M81 X-9): An Intermediate Mass Black Hole Candidate and its Environs
• The nature of ultra-luminous X-ray sources in NGC4565
• An XMM-Newton view of M101: I. The luminous X-ray source population
• Yet another galaxy identification for an ultraluminous X-ray source
• The Nature of Ultra Luminous X-ray Sources
• New optical spectra and general discussion on the nature of ULX's
• The Antennae Ultraluminous X-Ray Source, X-37, Is A Background Quasar
• A Deep Multicolor Survey V: The M Dwarf Luminosity Function
• The nature of the ultraluminous X-ray sources inside galaxies and their relation to local QSOs

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