Galactic Parameters from Whole Sky 2MASS Star Count
Astrophysics
2008-11-21 v1
Abstract
The whole sky differential star counts (DSC) with 1 degree resolution are retrieved from 2MASS online data service. Galaxy with double exponential thin and thick disks and a single power law luminosity function (LF) is used to interpret the 2MASS data. The slope of the DSC appears roughly isotropic over the whole sky, the average value is ~0.32, which corresponds to a power law index ~1.8 of the LF. We find that the scale-length and scale-height the thin disk are ~3.0 kpc and ~245 pc, and those of the thick disk are ~3.0 kpc and ~780 pc. The ratio of the thick disk to the thin disk is ~7%. The location of Sun above the disk is ~15 pc. A comparison of the data and model and their discrepancy are also provided.
Keywords
Cite
@article{arxiv.0811.3269,
title = {Galactic Parameters from Whole Sky 2MASS Star Count},
author = {C. K. Chang and C. M. Ko and T. H. Peng},
journal= {arXiv preprint arXiv:0811.3269},
year = {2008}
}