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

Abstract

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.

Citation

Wright, N. J., Drake, J. J., Guarcello, M. G., Aldcroft, T. L., Kashyap, V. L., Damiani, F., …Fruscione, A. (2023). The Chandra Cygnus OB2 Legacy Survey: Design and X-Ray Point-source Catalog. Astrophysical Journal Supplement, 269(1), Article 7. https://doi.org/10.3847/1538-4365/acdd62

• 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
• DOI: https://doi.org/10.3847/1538-4365/acdd62
• Keywords: pre-main sequence stars, massive stars, X-rays stars