Discoveries from a Near-infrared Proper Motion Survey Using Multi-epoch Two Micron All-Sky Survey Data

September 2010 • 2010ApJS..190..100K

Authors • Kirkpatrick, J. Davy • Looper, Dagny L. • Burgasser, Adam J. • Schurr, Steven D. • Cutri, Roc M. • Cushing, Michael C. • Cruz, Kelle L. • Sweet, Anne C. • Knapp, Gillian R. • Barman, Travis S. • Bochanski, John J. • Roellig, Thomas L. • McLean, Ian S. • McGovern, Mark R. • Rice, Emily L.

Abstract • We have conducted a 4030 deg2 near-infrared proper motion survey using multi-epoch data from the Two Micron All-Sky Survey (2MASS). We find 2778 proper motion candidates, 647 of which are not listed in SIMBAD. After comparison to Digitized Sky Survey images, we find that 107 of our proper motion candidates lack counterparts at B, R, and I bands and are thus 2MASS-only detections. We present results of spectroscopic follow-up of 188 targets that include the infrared-only sources along with selected optical-counterpart sources with faint reduced proper motions or interesting colors. We also establish a set of near-infrared spectroscopic standards with which to anchor near-infrared classifications for our objects. Among the discoveries are six young field brown dwarfs, five "red L" dwarfs, three L-type subdwarfs, twelve M-type subdwarfs, eight "blue L" dwarfs, and several T dwarfs. We further refine the definitions of these exotic classes to aid future identification of similar objects. We examine their kinematics and find that both the "blue L" and "red L" dwarfs appear to be drawn from a relatively old population. This survey provides a glimpse of the kinds of research that will be possible through time-domain infrared projects such as the UKIDSS Large Area Survey, various VISTA surveys, and WISE, and also through z- or y-band enabled, multi-epoch surveys such as Pan-STARRS and LSST.

Some of the spectroscopic data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Other spectroscopic data were collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.


IPAC Authors

Roc Cutri

IPAC Deputy Director


Davy Kirkpatrick

Senior Scientist