Constraining the Distribution of L- & T-Dwarfs in the Galaxy
Abstract
We estimate the thin disk scale height of the Galactic population of L- & T-dwarfs based on star counts from 15 deep parallel fields from the Hubble Space Telescope. From these observations, we have identified 28 candidate L- & T- dwarfs based on their (i'-z') color and morphology. By comparing these star counts to a simple Galactic model, we estimate the scale height to be 350+-50 pc that is consistent with the increase in vertical scale with decreasing stellar mass and is independent of reddening, color-magnitude limits, and other Galactic parameters. With this refined measure, we predict that less than 10^9 M_{sol} of the Milky Way can be in the form L- & T- dwarfs, and confirm that high-latitude, z~6 galaxy surveys which use the i'-band dropout technique are 97-100% free of L- & T- dwarf interlopers.
Cite
@article{arxiv.astro-ph/0508555,
title = {Constraining the Distribution of L- & T-Dwarfs in the Galaxy},
author = {Russell E. Ryan and Nimish P. Hathi and Seth H. Cohen and Rogier A. Windhorst},
journal= {arXiv preprint arXiv:astro-ph/0508555},
year = {2009}
}
Comments
4 pages, 4 figures, accepted to ApJL