Variability of Optical Counterparts in the Chandra Galactic Bulge Survey

Abstract

We present optical lightcurves of variable stars consistent with the positions of X-ray sources identified with the Chandra X-ray Observatory for the Chandra Galactic Bulge Survey. Using data from the Mosaic-II instrument on the Blanco 4m Telescope at CTIO, we gathered time-resolved photometric data on timescales from $\sim 2$ hr to 8 days over the $\frac{3}{4}$ of the X-ray survey containing sources from the initial GBS catalog. Among the lightcurve morphologies we identify are flickering in interacting binaries, eclipsing sources, dwarf nova outbursts, ellipsoidal variations, long period variables, spotted stars, and flare stars. $87\%$ of X-ray sources have at least one potential optical counterpart. $24\%$ 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.

arXiv commentAccepted for publication in the Astrophysical Journal Supplements

References in corpus (53)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The USNO-B Catalog
• A method for optimal image subtraction
• The UKIDSS Galactic Plane Survey
• First Results from the X-ray and Optical Survey of the Chandra Deep Field South
• Advection-Dominated Accretion and the Black Hole Event Horizon
• Dynamical Formation of Close Binary Systems in Globular Clusters
• The distances to Galactic low-mass X-ray binaries: consequences for black hole luminosities and kicks
• Jet-dominated states: an alternative to advection across black hole event horizons in `quiescent' X-ray binaries
• Advection-Dominated Accretion and Black Hole Event Horizons
• New Evidence for Black Hole Event Horizons from Chandra
• Investigating stellar-mass black hole kicks
• A Bayesian test for periodic signals in red noise
• Analysis of the Quiescent Low-Mass X-ray Binary Population in Galactic Globular Clusters
• The Galactic Population of Low- and Intermediate-Mass X-ray Binaries
• Dynamical Formation of Close Binaries in Globular Clusters II: Cataclysmic Variables
• The X-ray Spectra of Black Hole X-ray Novae in Quiescence as Measured by Chandra
• Populating the Galaxy with low-mass X-ray binaries
• X-ray Processing of ChaMPlane Fields: Methods and Initial Results for Selected Anti-Galactic Center Fields
• A Black Hole Nova Obscured by an Inner Disk Torus
• MAXI J1659-152: The shortest orbital period black-hole transient in outburst
• The Galactic Bulge Survey: outline and X-ray observations
• Swift J1753.5-0127: The Black Hole Candidate with the shortest orbital period
• Orbital Period and Outburst Luminosity of Transient Low Mass X-ray Binaries
• X-ray source populations in the Galactic Plane
• The hard quiescent spectrum of the neutron-star X-ray transient EXO 1745-248 in the globular cluster Terzan 5
• The black hole candidate MAXIJ1659-152 in and towards quiescence in X-ray and radio
• Could Black-Hole X-Ray Binaries Be Detected in Globular Clusters?
• XMM-Newton observations of two black hole X-ray transients in quiescence
• Chandra Multiwavelength Plane (ChaMPlane) Survey: an Introduction
• Echo-Mapping of Swift J1753.5-0127
• Black Holes in Short Period X-ray Binaries and the Transition to Radiatively Inefficient Accretion
• The X-ray source content of the XMM-Newton Galactic Plane Survey
• Three Additional Quiescent Low-Mass X-ray Binary Candidates in 47 Tucanae
• Near-Infrared Counterparts to Chandra X-ray Sources toward the Galactic Center. I. Statistics and a Catalog of Candidates
• The Galactic Bulge Survey: completion of the X-ray survey observations
• WFCAM Survey of M31 Globular Clusters: Low Mass X-ray Binaries
• Identification of twenty-three accreting binaries in the Galactic Bulge Survey
• ADAFs, accretion discs and outbursts in compact binaries
• X-ray observations of SU UMa throughout six outbursts
• CXOGBS~J173620.2--293338: A Candidate Symbiotic X-ray Binary Associated with a Bulge Carbon Star
• X-ray Sources with Periodic Variability in a Deep Chandra Image of the Galactic Center
• Radio sources in the Chandra Galactic Bulge survey
• Identification of 5 Interacting Binaries in the Galactic Bulge Survey
• ChaMPlane Deep Galactic Bulge Survey. I. Faint accretion-driven binaries in the Limiting Window
• X-ray Sources and Their Optical Counterparts in the Galactic Globular Cluster M12 (NGC 6218)
• CXOGBSJ174444.7-260330: a new long orbital period cataclysmic variable in a low state
• The ChaMPlane bright X-ray sources - Galactic longitudes l = 2-358 deg
• The X-ray quiescence of Swift J195509.6+261406 (GRB 070610): an optical bursting X-ray binary?
• Identification of Galactic Bulge Survey X-ray Sources with Tycho-2 Stars
• Near-infrared counterparts to the Galactic Bulge Survey X-ray source population
• Spectroscopic Follow-up of X-ray Sources in the ChaMPlane Survey: Identification of a New Cataclysmic Variable
• Near-infrared counterparts of Chandra X-ray sources toward the Galactic Center

Cited by in corpus (14)

• The Swift Bulge Survey: Motivation, Strategy, and First X-ray Results
• CXOGBS J174954.5-294335: A New Deeply-Eclipsing Intermediate Polar
• Discovery of a high state AM CVn binary in the Galactic Bulge Survey
• The X-ray Emissivity of Low-Density Stellar Populations
• The Relationship Between X-ray Luminosity and Duty Cycle for Dwarf Novae and their Specific Frequency in the Inner Galaxy
• The Chandra Galactic Bulge Survey: optical catalogue and point-source counterparts to X-ray sources
• Identifications of Faint Chandra Sources in the Globular Cluster M3
• Discovery of periodicities in two highly variable intermediate polars towards the Galactic Center
• Dynamical Modeling of CXOGBS J175553.2-281633: A 10 Hour Long Orbital Period Cataclysmic Variable
• Gemini Spectroscopy of Galactic Bulge Sources: A Population of Hidden Accreting Binaries Revealed?
• Spectroscopic classification of X-ray sources in the Galactic Bulge Survey
• Candidate Hα emission and absorption line sources in the Galactic Bulge Survey
• Discovery of a Long-Lived, High Amplitude Dusty Infrared Transient
• Constraining the nature of the accreting binary in CXOGBS J174623.5-310550