2003/04/30 by Andrew P. Digby, Andrew Digby, Nigel C. Hambly +6 · 2 citations
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Galactic halo #Galaxies: Formation, Evolution, Phenomena #Galaxy #Halo #Luminosity #Luminosity function #Physics #Proper motion #Sky #Stars #Stellar density #Stellar, planetary, and galactic studies #Subdwarf #White dwarf #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2003.06842.x
published as Mon.Not.Roy.Astron.Soc.344:583,2003 · 21 pages, 29 figures (Figs 4,6,7,11 are low res versions.) Published in MNRAS: minor explanatory additions to text, new subsection (5.2) on reddening, reference added
openalex publication_date 2003/09/01 · arxiv created 2003/10/29 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Using data from the Sloan Digital Sky Survey Early Data Release and SuperCOSMOS Sky Survey scans of POSS-I plates, we identify a sample of ∼2600 subdwarfs using reduced proper motion methods and strict selection criteria. This forms one of the largest and most reliable samples of candidate subdwarfs known, and enables us to determine accurate luminosity functions along many different lines of sight. We derive the subdwarf luminosity function with unprecedented accuracy to MV≲ 12.5, finding good agreement with recent local estimates but discrepancy with results for the more distant spheroid. This provides further evidence that the inner and outer parts of the stellar halo cannot be described by a single density distribution. We also find that the form of the inner spheroid density profile within heliocentric distances of 2.5 kpc is closely matched by a power law with an index of α=−3.15 ± 0.3.