Title

Intermediate Resolution Near-Infrared Spectroscopy Of 36 Late M Dwarfs

Keywords

brown dwarfs; planetary systems; stars: fundamental parameters; stars: low-mass; stars: rotation; techniques: radial velocities

Abstract

We present observations of 36 late M dwarfs obtained with the Keck II/NIRSPEC in the J band at a resolution of ∼20,000. We have measured projected rotational velocities, absolute radial velocities, and pseudo-equivalent widths of atomic lines. Twelve of our targets did not have previous measurements in the literature. For the other 24 targets, we confirm previously reported measurements. We find that 13 stars from our sample have v sin i below our measurement threshold (12kms -1) whereas four of our targets are fast rotators (v sin i > 30kms -1). As fast rotation causes spectral features to be washed out, stars with low projected rotational velocities are sought for radial velocity surveys. At our intermediate spectral resolution, we have confirmed the identification of neutral atomic lines reported in McLean etal. We also calculated pseudo-equivalent widths of 12 atomic lines. Our results confirm that the pseudo-equivalent width of K I lines is strongly dependent on spectral types. We observe that the pseudo-equivalent width of Fe I and Mn I lines remains fairly constant with later spectral type. We suggest that these lines are particularly suitable for deriving metallicities for late M dwarfs. © 2012. The American Astronomical Society. All rights reserved.

Publication Date

10-1-2012

Publication Title

Astronomical Journal

Volume

144

Issue

4

Number of Pages

-

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1088/0004-6256/144/4/99

Socpus ID

84866348674 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84866348674

This document is currently not available here.

Share

COinS