Skip to main content

Research Repository

Advanced Search

Optical and Infrared Counterparts of the X-Ray Sources Detected in the Chandra Cygnus OB2 Legacy Survey

Guarcello, M. G.; Drake, J. J.; Wright, N. J.; Naylor, T.; Flaccomio, E.; Kashyap, V. L.; García-Alvarez, D.


M. G. Guarcello

J. J. Drake

T. Naylor

E. Flaccomio

V. L. Kashyap

D. García-Alvarez


The young massive OB association Cygnus OB2, in the Cygnus X complex, is the closest (∼1400 pc) star-forming region to the Sun hosting thousands of young low-mass stars and up to 1000 OB stars, among which are some of the most massive stars known in our Galaxy. This region holds great importance for several fields of modern astrophysics, such as the study of the physical properties of massive and young low-mass stars and the feedback provided by massive stars on star and planet formation processes. Cyg OB2 has been recently observed with Chandra/ACIS-I as part of the 1.08 Ms Chandra Cygnus OB2 Legacy Project. This survey detected 7924 X-ray sources in a square degree area centered on Cyg OB2. Since a proper classification and study of the observed X-ray sources also requires the analysis of their optical and infrared counterparts, we combined a large and deep set of optical and infrared catalogs available for this region with our new X-ray catalog. In this paper we describe the matching procedure and present the combined catalog containing 5703 sources. We also briefly discuss the nature of the X-ray sources with optical and infrared counterparts using their position in the color–magnitude and color–color diagrams.

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
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 269
Issue 1
Pages 9
Keywords Catalogs, Astronomy databases


Wright_published version (4.4 Mb)

Publisher Licence URL

Copyright Statement
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.

You might also like

Downloadable Citations