Characterization of High Proper Motion Objects from the Wide-field Infrared Survey Explorer

TL;DR

This study analyzes high proper motion objects using WISE and 2MASS data, identifying nearby, metal-poor, and late-type stars, including subdwarfs and blue L dwarfs, with some likely members of the Galactic halo or thick disk.

Contribution

It provides a detailed spectroscopic and kinematic characterization of high proper motion objects, including new classifications and potential nearby star candidates.

Findings

Identification of 41 objects with spectral types M4-T2.5.

Discovery of 11 blue L dwarfs and five subdwarfs.

Several objects likely within 20 parsecs, including some halo members.

Abstract

We present an analysis of high proper motion objects that we have found in a recent study and in this work with multi-epoch astrometry from the Wide-field Infrared Survey Explorer (WISE). Using photometry and proper motions from 2MASS and WISE, we have identified the members of this sample that are likely to be late type, nearby, or metal poor. We have performed optical and near-infrared spectroscopy on 41 objects, from which we measure spectral types that range from M4-T2.5. This sample includes 11 blue L dwarfs and five subdwarfs; the latter were also classified as such in the recent study by Kirkpatrick and coworkers. Based on their spectral types and photometry, several of our spectroscopic targets may have distances of <20 pc with the closest at ~12 pc. The tangential velocities implied by the spectrophotometric distances and proper motions indicate that four of the five subdwarfs are probably members of the Galactic halo while several other objects, including the early-T dwarf WISE J210529.08-623558.7, may belong to the thick disk.