Discovery and analysis of a ULX nebula in NGC 3521
Abstract
We present Very Large Telescope/X-shooter and Chandra X-ray observatory/ACIS observations of the ULX [SST2011] J110545.62 + 000016.2 in the galaxy NGC 3521. The source identified as a candidate near-infrared counterpart to the ULX in our previous study shows an emission line spectrum of numerous recombination and forbidden lines in the visible and near-infrared spectral regime. The emission from the candidate counterpart is spatially extended (∼34 pc) and appears to be connected with an adjacent H II region, located ∼138 pc to the NE. The measured velocities of the emission lines confirm that both the candidate counterpart and H II region reside in NGC 3521. The intensity ratios of the emission lines from the ULX counterpart show that the line emission originates from the combined effect of shock and photoionization of low metallicity (12 + log (O/H) = 8.19 ± 0.11) gas. Unfortunately, there is no identifiable spectral signature directly related to the photosphere of the mass-donor star in our spectrum. From the archival Chandra data, we derive the X-ray luminosity of the source in the 0.3–7 keV range to be (1.9 ± 0.8) × 10⁴⁰ er g cm⁻² s⁻¹, almost a factor of four higher than what is previously reported.
Additional Information
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model). Accepted 2019 July 29. Received 2019 July 17; in original form 2019 June 4. Published: 05 August 2019. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme 0100.D-0660(B). We would like to thank the anonymous referee whose valuable comments helped improve the quality of this work. KML would like to thank Davide Lena for valuable discussions. PGJ and KML acknowledge funding from the European Research Council under ERC Consolidator Grant agreement no. 647208. TPR acknowledges funding from the Science and Technology Facilities Council (STFC) as part of the consolidated grant ST/L00075X/1. MAPT acknowledges support via a Ramón y Cajal Fellowship (RYC-2015-17854). MAPT also acknowledges support by the Spanish Ministry of Economy, Industry and Competitiveness under grant AYA2017-83216-P. DJW acknowledges support from an STFC Ernest Rutherford Fellowship. We have made use of the SIMBAD data base, operated at CDS, Strasbourg, France; of the NASA/IPAC Extragalactic Data base (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 Catalogue, and software provided by the Chandra X-ray Center (CXC) in the application packages CIAO, ChIPS, and Sherpa.Attached Files
Published - stz2127.pdf
Submitted - 1907.12814.pdf
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Additional details
- Eprint ID
- 97799
- Resolver ID
- CaltechAUTHORS:20190812-150823615
- 647208
- European Research Council (ERC)
- ST/L00075X/1
- Science and Technology Facilities Council (STFC)
- RYC-2015-17854
- Ramón y Cajal Fellowship
- AYA2017-83216-P
- Ministerio de Economía, Industria y Competitividad (MINECO)
- NASA/JPL/Caltech
- Created
-
2019-08-12Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Space Radiation Laboratory, Astronomy Department