La Silla QUEST RR Lyrae Star Survey: Region I

Abstract

A search for RR Lyrae stars (RRLS) in 840 sq.deg. of the sky in right ascension 150 - 210 deg and declination -10 - +10 deg yielded 1013 type ab and 359 type c RRLS. This sample is used to study the density profile of the Galactic halo, halo substructures, and the Oosterhoff type of the halo over distances from 5 to 80 kpc. The halo is flattened towards the Galactic plane, and its density profile steepens in slope at galactocentric distances greater than 25 kpc. The RRLS in the stellar stream from the Sagittarius dwarf spheroidal (dSph) galaxy match well the model of Law and Majewski for the stars that were stripped 1.3 to 3.2 Gyr ago, but not for the ones stripped 3.2 to 5.0 Gyr ago. Over densities are found at the locations of the Virgo Overdensity and the Virgo Stellar Stream. Within 1 deg of 1220-1, which Jerjen et al. identify as a halo substructure at a distance of 24 kpc, there are 4 RRLS that are possibly members. Away from substructures, the RRLS are a mixture of Oosterhoff types I and II, but mostly OoI (73%). The accretion of galaxies resembling in RRLS content the most massive Milky Way satellites (LMC, SMC, For,Sgr) may explain this preponderance of OoI. Six new RRLS and 3 new anomalous Cepheids were found in the Sextans dSph galaxy.

90 pages, 23 figures

References in corpus (30)

• Two Stellar Components in the Halo of the Milky Way
• The accretion origin of the Milky Way's stellar halo
• The Dual Origin of Stellar Halos
• An Orphan in the "Field of Streams"
• Detection of a 60 Degree-Long Dwarf Galaxy Debris Stream
• The Invisibles: A Detection Algorithm to Trace the Faintest Milky Way Satellites
• The Hercules-Aquila Cloud
• The QUEST RR Lyrae Survey II: The Halo Overdensities in the First Catalog
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: Variation of the Metallicity Distribution Function Along the Sagittarius Stream
• The Overdensity in Virgo, Sagittarius Debris, and the Asymmetric Spheroid
• Chemical Abundances and Kinematics in Globular Clusters and Local Group Dwarf Galaxies and Their Implications for Formation Theories of the Galactic Halo
• Discovery of a Giant Stellar Tidal Stream Around the Disk Galaxy NGC 4013
• RR Lyrae Variables in M33. I. Evidence For a Field Halo Population
• Kinematic Decoupling of Globular Clusters with Extended Horizontal-Branch
• 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
• Fashionably Late? Building up the Milky Way's Inner Halo
• Revealing Substructure in the Galactic Halo - The SEKBO RR Lyrae Survey
• High-resolution spectroscopy of RGB stars in the Sagittarius Streams. I. Radial velocities and chemical abundances
• The Variable Stars of the Draco Dwarf Spheroidal Galaxy - Revisited
• Whiting 1: the youngest globular cluster associated with the Sgr dSph
• Chemical Inhomogeneities in the Milky Way Stellar Halo
• Identifying Contributions to the Stellar Halo from Accreted, Kicked-Out, and In Situ Populations
• The QUEST Large Area CCD Camera
• Proper Motions in Kapteyn Selected Area 103: A Preliminary Orbit for the Virgo Stellar Stream
• No Excess of RR Lyrae Stars in the Canis Major Overdensity
• The Globular Cluster M15. I. Identification, Discovery, and Period Determination of Variable Stars
• Stellar over-densities in the halo: the extent of the Virgo over-density
• RR Lyrae stars in the southern globular cluster NGC 362
• Spatial and Velocity clumping in an SDSS blue horizontal branch star catalogue

Cited by in corpus (51)

• On a new theoretical framework for RR Lyrae stars I: the metallicity dependence
• Deciphering the 3D structure of the old Galactic bulge from the OGLE RR Lyrae stars
• Discovery of two neighboring satellites in the Carina constellation with MagLiteS
• Chemo-kinematics of the $Gaia$ RR Lyrae: the halo and the disc
• Stellar Streams and Clouds in the Galactic Halo
• Comparative performance of selected variability detection techniques in photometric time series
• Weak Galactic halo--dwarf spheroidal connection from RR Lyrae stars
• The Geometry of Sagittarius Stream from Pan-STARRS1 3$\pi$ RR Lyrae
• New NIR light-curve templates for classical Cepheids
• Search for RR Lyrae stars in DES ultra-faint systems: Grus I, Kim 2, Phoenix II, and Grus II
• Stacking the Invisibles: A Guided Search for Low-Luminosity Milky Way Satellites
• The Galactic Thick Disc density profile traced with RR Lyrae stars
• Discovery of distant RR Lyrae stars in the Milky Way using DECam
• Unmixing the Galactic Halo with RR Lyrae tagging
• Strong RR Lyrae excess in the Hercules-Aquila Cloud
• Probing the galactic halo with RR Lyrae stars I: The catalog
• Variable stars in the field of the Hydra II ultra-faint dwarf galaxy
• On the Impact of Helium Content on the RR Lyrae Distance Scale
• Weak Galactic Halo--Fornax dSph Connection from RR Lyrae Stars
• A comprehensive view of the Virgo Stellar Stream
• Mapping the Tidal Disruption of the Hercules Dwarf: A Wide-Field DECam Imaging Search for RR Lyrae Stars
• Gaia RR Lyrae Stars in Nearby Ultra-Faint Dwarf Satellite Galaxies
• Local RR Lyrae Stars: native and alien
• Identifying RR Lyrae Variable Stars in Six Years of the Dark Energy Survey
• Charting Unexplored Dwarf Galaxy Territory With RR Lyrae
• The Virgo Overdensity Explained
• Newly Discovered RR Lyrae Stars in the SDSSXPanXSTARRS1XCatalina Footprint
• Mapping the anisotropic Galactic stellar halo with Blue Horizontal Branch stars
• The QUEST-La Silla AGN Variability Survey
• Serendipitous discovery of RR Lyrae stars in the Leo V ultra-faint galaxy
• Probing the Galactic halo with RR Lyrae stars $-$ III. The chemical and kinematic properties of the stellar halo
• Disentangling the Virgo Overdensity with RR Lyrae stars
• The Population of Pulsating Variable Stars in the Sextans Dwarf Spheroidal Galaxy
• What is the Milky Way outer halo made of? High resolution spectroscopy of distant red giants
• STREGA: STRucture and Evolution of the GAlaxy. I. Survey Overview and First Results
• Homogeneous Photometry VI: Variable Stars in the Leo I Dwarf Spheroidal Galaxy
• RR Lyrae Variable Stars in the Crater II Dwarf Galaxy
• The Identification of RR Lyrae and Delta Scuti Stars from Variable GALEX Ultraviolet Sources
• Impact of distance determinations on Galactic structure. II. Old tracers
• RR Lyrae Stars in the Field of Sagittarius II
• An optimized Method to Identify RR Lyrae stars in the SDSS X Pan-STARRS1 Overlapping Area Using a Bayesian Generative Technique
• A Magellanic origin for the Virgo substructure
• RR Lyrae stars as probes of the outer Galactic halo: Chemical and kinematic analysis of a pilot sample
• Inferring the Galactic potential with Gaia and friends: synergies with other surveys
• Predicting light curves of RR Lyrae variables using artificial neural network based interpolation of a grid of pulsation models
• Determining the Scale Length and Height of the Milky Way's Thick Disc Using RR~Lyrae
• Differential Source Count for Gamma Ray Bursts
• On the Use of Field RR Lyrae as Galactic Probes -- VIII. Early Formation of the Galactic Spheroid
• RR Lyrae stars in the newly discovered ultra-faint dwarf galaxy Centaurus I
• rrlfe: Software for Generating and Applying Metallicity Calibrations for RR Lyrae Variable Stars Across a Wide Range of Phases and Temperatures
• The spectral Petersen diagram as a new tool to map pulsation modes in variable stars