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The Chandra Cygnus OB2 Legacy Survey: Design and X-Ray Point-source Catalog

Wright, Nicholas J.; Drake, Jeremy J.; Guarcello, Mario G.; Aldcroft, Tom L.; Kashyap, Vinay L.; Damiani, Francesco; DePasquale, Joe; Fruscione, Antonella


Jeremy J. Drake

Mario G. Guarcello

Tom L. Aldcroft

Vinay L. Kashyap

Francesco Damiani

Joe DePasquale

Antonella Fruscione


The Cygnus OB2 association is the largest concentration of young and massive stars within 2 kpc of the Sun, including an estimated ∼65 O-type stars and hundreds of OB stars. The Chandra Cygnus OB2 Legacy Survey is a large imaging program undertaken with the Advanced CCD Imaging Spectrometer on board the Chandra X-ray Observatory. The survey has imaged the central 0.5 deg2 of the Cyg OB2 association with an effective exposure of ∼120 ks and an outer 0.35 deg2 area with an exposure of ∼60 ks. Here we describe the survey design and observations, discuss the data reduction and source detection, and present a catalog of ∼8000 X-ray point sources. The survey design employs a grid of 36 heavily (∼50%) overlapping pointings, a method that overcomes Chandra's low off-axis sensitivity and produces a highly uniform exposure over the inner 0.5 deg2. The full X-ray catalog is described here and is made available online.

Journal Article Type Article
Acceptance Date Feb 2, 2017
Online Publication Date Oct 25, 2023
Publication Date Nov 1, 2023
Deposit Date Oct 30, 2023
Publicly Available Date Oct 30, 2023
Journal The Astrophysical Journal Supplement Series
Print ISSN 0067-0049
Electronic ISSN 1538-4365
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 269
Issue 1
Article Number 7
Keywords pre-main sequence stars, massive stars, X-rays stars


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Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

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