A Systematic Search for Near-Infrared Counterparts of Nearby Ultraluminous X-ray sources (II)
Abstract
We present the results of our continued systematic search for near-infrared (NIR) candidate counterparts to ultraluminous X-ray sources (ULXs) within 10 Mpc. We observed 42 ULXs in 24 nearby galaxies and detected NIR candidate counterparts to 15 ULXs. Fourteen of these ULXs appear to have a single candidate counterpart in our images and the remaining ULX has two candidate counterparts. Seven ULXs have candidate counterparts with absolute magnitudes in the range between −9.26 and −11.18 mag, consistent with them being red supergiants (RSGs). The other eight ULXs have candidate counterparts with absolute magnitudes too bright to be a single stellar source. Some of these NIR sources show extended morphology or colours expected for active galactic nuclei (AGNs), strongly suggesting that they are likely stellar clusters or background galaxies. The RSG candidate counterparts form a valuable sample for follow-up spectroscopic observations to confirm their nature, with the ultimate goal of directly measuring the mass of the compact accretor that powers the ULX using binary Doppler shifts.
Additional Information
© 2017 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2017 April 3. Received 2017 April 3; in original form 2017 February 1. Published: 06 April 2017. This research is based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. We have made use of the SIMBAD data base, operated at CDS, Strasbourg, France; of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration; and of data obtained from the Chandra Data Archive and the Chandra Source Catalog, and software provided by the Chandra X-ray Center (CXC) in the application packages CIAO, ChIPS and Sherpa. PGJ and KML acknowledge funding from the European Research Council under ERC Consolidator Grant agreement No. 647208. TPR acknowledges funding from Science & Technology Facilities Council (STFC) as part of the consolidated grant ST/L00075X/1.Attached Files
Published - stx857.pdf
Submitted - 1704.01068.pdf
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Additional details
- Eprint ID
- 78527
- Resolver ID
- CaltechAUTHORS:20170623-145105446
- NASA/JPL/Caltech
- 647208
- European Research Council (ERC)
- ST/L00075X/1
- Science and Technology Facilities Council (STFC)
- Created
-
2017-06-23Created from EPrint's datestamp field
- Updated
-
2021-11-15Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory, Astronomy Department