We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.

Durham Research Online
You are in:

Chandra observations of NuSTAR serendipitous sources near the Galactic Plane.

Tomsick, John A. and Lansbury, George B. and Rahoui, Farid and Aird, James and Alexander, David M. and Clavel, Maïca and Cuturilo, AnaSofija and Fornasini, Francesca M. and Hong, JaeSub and Klindt, Lizelke and Stern, Daniel (2018) 'Chandra observations of NuSTAR serendipitous sources near the Galactic Plane.', The astrophysical journal., 869 (2). p. 171.


The Nuclear Spectroscopic Telescope Array (NuSTAR) serendipitous survey has already uncovered a large number of active galactic nuclei (AGNs), providing new information about the composition of the cosmic X-ray background. For AGNs off the Galactic plane, it has been possible to use existing X-ray archival data to improve source localizations, identify optical counterparts, and classify the AGNs with optical spectroscopy. However, near the Galactic plane, better X-ray positions are necessary to achieve optical or near-IR identifications due to the higher levels of source crowding. Thus, we have used observations with the Chandra X-ray Observatory to obtain the best possible X-ray positions. With eight observations, we have obtained coverage for 19 NuSTAR serendips within 12° of the plane. One or two Chandra sources are detected within the error circle of 15 of the serendips, and we report on these sources and search for optical counterparts. For one source (NuSTAR J202421+3350.9), we obtained a new optical spectrum and detected the presence of hydrogen emission lines. The source is Galactic, and we argue that it is likely a cataclysmic variable. For the other sources, the Chandra positions will enable future classifications in order to place limits on faint Galactic populations, including high-mass X-ray binaries and magnetars.

Item Type:Article
Full text:(VoR) Version of Record
Download PDF
Publisher Web site:
Publisher statement:© 2018. The American Astronomical Society. All rights reserved.
Date accepted:09 November 2018
Date deposited:09 January 2019
Date of first online publication:26 November 2018
Date first made open access:09 January 2019

Save or Share this output

Look up in GoogleScholar