Constraining the distribution of L and T dwarfs in the galaxy

R. E. Ryan, N. P. Hathi, S. H. Cohen, Rogier Windhorst

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

We estimate the thin-disk scale height of the Galactic population of L and 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 and T dwarfs based on their i′-z′ color and morphology. By comparing these star counts with a simple Galactic model, we estimate the scale height to be 350 ± 50 pc, which 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 109 M of the Milky Way can be in the form of L and T dwarfs and confirm that high-latitude, z ≃6 galaxy surveys that use the i′-band dropout technique are 97%-100% free of L and T dwarf interlopers.

Original languageEnglish (US)
JournalAstrophysical Journal
Volume631
Issue number2 II
DOIs
StatePublished - Oct 1 2005

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scale height
galaxies
dropouts
color
stars
estimates
stellar mass
Hubble Space Telescope
polar regions
distribution
parameter

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Constraining the distribution of L and T dwarfs in the galaxy. / Ryan, R. E.; Hathi, N. P.; Cohen, S. H.; Windhorst, Rogier.

In: Astrophysical Journal, Vol. 631, No. 2 II, 01.10.2005.

Research output: Contribution to journalArticle

Ryan, R. E. ; Hathi, N. P. ; Cohen, S. H. ; Windhorst, Rogier. / Constraining the distribution of L and T dwarfs in the galaxy. In: Astrophysical Journal. 2005 ; Vol. 631, No. 2 II.
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