RR Lyrae in XSTPS: The halo density profile in the North Galactic Cap

Abstract

We present a catalog of RR Lyrae stars (RRLs) observed by the Xuyi Schmidt Telescope Photometric Survey (XDSS). The area we consider is located in the North Galactic Cap, covering 376.75 sq deg at RA $\approx$ 150 deg and Dec $\approx$ 27 deg down to a magnitude limit of i $\approx$ 19. Using the variability information afforded by the multi-epoch nature of our XDSS data, combined with colors from the Sloan Digital Sky Survey, we are able to identify candidate RRLs. We find 318 candidates, derive distances to them and estimate the detection efficiency. The majority of our candidates have more than 12 observations and for these we are able to calculate periods. These also allows us to estimate our contamination level, which we predict is between 30% to 40%. Finally we use the sample to probe the halo density profile in the 9-49 kpc range and find that it can be well fitted by a double power law. We find good agreement between this model and the models derived for the South Galactic Cap using the Watkins et al. (2009) and Sesar et al. (2010) RRL data-sets, after accounting for possible contamination in our data-set from Sagittarius stream members. We consider non-spherical double power law models of the halo density profile and again find agreement with literature data-sets, although we have limited power to constrain the flattening due to our small survey area. Much tighter constraints will be placed by current and future wide-area surveys, most notably ESA's astrometric Gaia mission. Our analysis demonstrates that surveys with a limited number of epochs can effectively be mined for RRLs. Our complete sample is provided as accompanying online material.

arXiv comment14 pages, ApJ (in press)

References in corpus (36)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The Sloan Digital Sky Survey: Technical Summary
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• The New Galaxy: Signatures of its Formation
• The Sloan Digital Sky Survey Quasar Catalog V. Seventh Data Release
• The Field of Streams: Sagittarius and its Siblings
• Possible Gravitational Microlensing of a Star in the Large Magellanic Cloud
• The Ghost of Sagittarius and Lumps in the Halo of the Milky Way
• Exploring the Optical Transient Sky with the Palomar Transient Factory
• The Milky Way's Circular Velocity Curve to 60 kpc and an Estimate of the Dark Matter Halo Mass from Kinematics of ~2400 SDSS Blue Horizontal Branch Stars
• The Milky Way Tomography with SDSS: II. Stellar Metallicity
• The Sagittarius Dwarf Galaxy: a Model for Evolution in a Triaxial Milky Way Halo
• The Sloan Digital Sky Survey-II Supernova Survey: Technical Summary
• A Low Latitude Halo Stream around the Milky Way
• The Milky Way stellar halo out to 40 kpc : Squashed, broken but smooth
• Science performance of Gaia, ESA's space-astrometry mission
• Substructure revealed by RR Lyraes in SDSS Stripe 82
• Probing the Outer Galactic halo with RR Lyrae from the Catalina Surveys
• The Sloan Digital Sky Survey-II Supernova Survey: Search Algorithm and Follow-up Observations
• Light Curve Templates and Galactic Distribution of RR Lyrae Stars from Sloan Digital Sky Survey Stripe 82
• The Milky Way Tomography with SDSS: III. Stellar Kinematics
• The Shape and Profile of the Milky Way Halo as Seen by the CFHT Legacy Survey
• Kinematics of SDSS subdwarfs: Structure and substructure of the Milky Way halo
• The QUEST RR Lyrae Survey II: The Halo Overdensities in the First Catalog
• Light and Motion in SDSS Stripe 82: The Catalogues
• Exploring the Variable Sky with LINEAR. III. Classification of Periodic Light Curves
• Exploring the Variable Sky with LINEAR. II. Halo Structure and Substructure Traced by RR Lyrae Stars to 30 kpc
• Evidence for a Milky Way Tidal Stream Reaching Beyond 100 kpc
• Evidence for Distinct Components of the Galactic Stellar Halo from 838 RR Lyrae Stars Discovered in the LONEOS-I Survey
• Analysis of RR Lyrae Stars in the Northern Sky Variability Survey
• Revealing Substructure in the Galactic Halo - The SEKBO RR Lyrae Survey
• LSS-GAC - A LAMOST Spectroscopic Survey of the Galactic Anti-center
• The Period-Luminosity Relation of RR Lyrae Stars in the SDSS Photometric System
• A Preliminary Calibration of the RR Lyrae Period-Luminosity Relation at Mid-Infrared Wavelengths: WISE Data
• Mid-Infrared Period--Luminosity Relations of RR Lyrae Stars Derived from the AllWISE Data Release
• Standard candles from the Gaia perspective

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