Probing Galactic Structure with the Spatial Correlation Function of SEGUE G-dwarf Stars
Abstract
We measure the two-point correlation function of G-dwarf stars within 1-3 kpc of the Sun in multiple lines-of-sight using the Schlesinger et al. G-dwarf sample from the SDSS SEGUE survey. The shapes of the correlation functions along individual SEGUE lines-of-sight depend sensitively on both the stellar-density gradients and the survey geometry. We fit smooth disk galaxy models to our SEGUE clustering measurements, and obtain strong constraints on the thin- and thick-disk components of the Milky Way. Specifically, we constrain the values of the thin- and thick-disk scale heights with 3% and 2% precision, respectively, and the values of the thin- and thick-disk scale lengths with 20% and 8% precision, respectively. Moreover, we find that a two-disk model is unable to fully explain our clustering measurements, which exhibit an excess of clustering at small scales (< 50 pc). This suggests the presence of small-scale substructure in the disk system of the Milky Way.
Cite
@article{arxiv.1507.01593,
title = {Probing Galactic Structure with the Spatial Correlation Function of SEGUE G-dwarf Stars},
author = {Qingqing Mao and Andreas A. Berlind and Kelly Holley-Bockelmann and Katharine J. Schlesinger and Jennifer A. Johnson and Constance M. Rockosi and Timothy C. Beers and Donald P. Schneider and Kaike Pan and Dmitry Bizyaev and Elena Malanushenko},
journal= {arXiv preprint arXiv:1507.01593},
year = {2015}
}
Comments
8 pages, 10 figures, submitted to ApJ