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Title: VARIABILITY OF OPTICAL COUNTERPARTS IN THE CHANDRA GALACTIC BULGE SURVEY

Journal Article · · Astrophysical Journal, Supplement Series
; ; ; ; ;  [1]; ;  [2];  [3];  [4]; ;  [5];  [6];  [7];  [8];  [9]
  1. Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States)
  2. SRON, Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)
  3. Department of Astrophysics, IMAPP, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen (Netherlands)
  4. Department of Physics, Texas Tech University, Box 41051, Science Building, Lubbock, TX 79409-1051 (United States)
  5. Astronomy and Astrophysics, Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom)
  6. Department of Physics, University of Alberta, CCIS 4-183, Edmonton, AB T6G 2E1 (Canada)
  7. Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)
  8. Department of Physics, Massachussettes Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307 (United States)
  9. Department of Physics, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431-0991 (United States)

We present optical light curves of variable stars consistent with the positions of X-ray sources identified with the Chandra X-ray Observatory for the Chandra Galactic Bulge Survey (GBS). Using data from the Mosaic-II instrument on the Blanco 4 m Telescope at CTIO, we gathered time-resolved photometric data on timescales from ∼2 hr to 8 days over the 3/4 of the X-ray survey containing sources from the initial GBS catalog. Among the light curve morphologies we identify are flickering in interacting binaries, eclipsing sources, dwarf nova outbursts, ellipsoidal variations, long period variables, spotted stars, and flare stars. Eighty-seven percent of X-ray sources have at least one potential optical counterpart. Twenty-seven percent of these candidate counterparts are detectably variable; a much greater fraction than expected for randomly selected field stars, which suggests that most of these variables are real counterparts. We discuss individual sources of interest, provide variability information on candidate counterparts, and discuss the characteristics of the variable population.

OSTI ID:
22340164
Journal Information:
Astrophysical Journal, Supplement Series, Vol. 214, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0067-0049
Country of Publication:
United States
Language:
English