Metallicities and ages of stellar populations at a high Galactic latitude field

Abstract

We present an analysis of $UBVRI$ data from the Selected Area SA 141. By applying recalibrated methods of measuring ultraviolet excess (UVX), we approximate abundances and absolute magnitudes for 368 stars over 1.3 square degrees out to distances over 10 kpc. With the density distribution constrained from our previous photometric parallax investigations and with sufficient accounting for the metallicity bias in the UVX method, we are able to compare the vertical abundance distribution to those measured in previous studies. We find that the abundance distribution has an underlying uniform component consistent with previous spectroscopic results that posit a monometallic thick disk and halo with abundances of $[Fe/H]$ = $-$0.8 and $-$1.4, respectively. However, there are a number of outlying data points that may indicate contamination by more metal-rich halo streams. The absence of vertical abundance gradients in the Galactic stellar populations and the possible presence of interloping halo streams would be consistent with expectations from merger models of Galaxy formation. We find that our UVX method has limited sensitivity in exploring the metallicity distribution of the distant Galactic halo, owing to the poor constraint on the $UBV$ properties of very metal-poor stars. The derivation of metallicities from broadband $UBV$ photometry remains fundamentally sound for the exploration of the halo but is in need of both improved calibration and superior data.

arXiv comment11 pages, 11 figures, accepted for publication in MNRAS Journal

References in corpus (34)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• The u'g'r'i'z' Standard Star Network
• The Milky Way Tomography with SDSS: I. Stellar Number Density Distribution
• The New Galaxy: Signatures of its Formation
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: I. Morphology of the Sagittarius Core and Tidal Arms
• The Field of Streams: Sagittarius and its Siblings
• A standard stellar library for evolutionary synthesis: I. Calibration of theoretical spectra
• The Ghost of Sagittarius and Lumps in the Halo of the Milky Way
• Two Stellar Components in the Halo of the Milky Way
• A standard stellar library for evolutionary synthesis: II. The M dwarf extension
• The Milky Way Tomography with SDSS: II. Stellar Metallicity
• A Spectroscopic Study of the Ancient Milky Way: F- and G-Type Stars in the Third Data Release of the Sloan Digital Sky Survey
• A Low Latitude Halo Stream around the Milky Way
• Identification of A-colored Stars and Structure in the Halo of the Milky Way from SDSS Commissioning Data
• The ACS Survey of Galactic Globular Clusters. II. Stellar Evolution Tracks, Isochrones, Luminosity Functions, and Synthetic Horizontal-Branch Models
• The Y^2 Stellar Evolutionary Tracks
• Candidate RR Lyrae Stars Found in Sloan Digital Sky Survey Commissioning Data
• Detection of a 60 Degree-Long Dwarf Galaxy Debris Stream
• Simulation of Stellar Objects in SDSS Color Space
• Starcounts Redivivus. IV. Density Laws Through Photometric Parallaxes
• Colors of 2625 Quasars at 0<z<5 Measured in the Sloan Digital Sky Survey Photometric System
• The QUEST RR Lyrae Survey: Confirmation of the Clump at 50 kpc and Other Over-Densities in the Outer Halo
• The Merging History of the Milky Way
• Exploring Halo Substructure with Giant Stars: A diffuse star cloud or tidal debris around the Milky Way in Triangulum-Andromeda
• 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 Sgr dSph hosts a metal-rich population
• Metal-poor Field Blue Stragglers: More Evidence for Mass Transfer
• The Closest View of a Dwarf Galaxy: New Evidence on the Nature of the Canis Major over-density
• Starcounts Redivivus II: Deep Starcounts with Keck and HST and the Luminosity Function of the Galactic Halo
• Large-scale variations of the dust optical properties in the Galaxy
• A CCD Study of High Latitude Galactic Structure: Testing the Model Parameters
• The metallicity distribution of F/G dwarfs derived from BATC survey data
• The Metallicity Distribution of Distant F and G type stars in the CFHT Legacy Survey Deep Field

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• Local Stellar Kinematics from RAVE data - VII. Metallicity Gradients from Red Clump Stars
• The stellar metallicity distribution in intermediate latitude fields with BATC and SDSS data
• The stellar metallicity distribution of the Milky Way from the BATC survey
• Luminosity-Colour Relations for Red Clump Stars
• A Monte-Carlo Method for Estimating Stellar Photometric Metallicity Distributions
• Metallicity and absolute magnitude calibrations for F-G type main-sequence stars in the Gaia era