An infrared/x-ray survey for new members of the taurus star-forming region

Kevin Luhman, E. E. Mamajek, P. R. Allen, K. L. Cruz

Research output: Contribution to journalArticle

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Abstract

We present the results of a search for new members of the Taurus star-forming region using data from the Spitzer Space Telescope and the XMM-Newton Observatory. We have obtained optical and near-infrared spectra of 44 sources that exhibit red Spitzer colors that are indicative of stars with circumstellar disks and 51 candidate young stars that were identified by Scelsi and coworkers using XMM-Newton. We also performed spectroscopy on four possible companions to members of Taurus that were reported by Kraus and Hillenbrand. Through these spectra, we have demonstrated the youth and membership of 41 sources, 10 of which were independently confirmed as young stars by Scelsi and coworkers. Five of the new Taurus members are likely to be brown dwarfs based on their late spectral types (>M6). One of the brown dwarfs has a spectral type of L0, making it the first known L-type member of Taurus and the least massive known member of the region (M 4-7 M Jup). Another brown dwarf exhibits a flat infrared spectral energy distribution, which indicates that it could be in the protostellar class I stage (star+disk+envelope). Upon inspection of archival images from various observatories, we find that one of the new young stars has a large edge-on disk (r = 25 = 350 AU). The scattered light from this disk has undergone significant variability on a timescale of days in optical images from the Canada-France-Hawaii Telescope. Using the updated census of Taurus, we have measured the initial mass function for the fields observed by XMM-Newton. The resulting mass function is similar to previous ones that we have reported for Taurus, showing a surplus of stars at spectral types of K7-M1 (0.6-0.8 M) relative to other nearby star-forming regions, such as IC 348, Chamaeleon I, and the Orion Nebula Cluster.

Original languageEnglish (US)
Pages (from-to)399-419
Number of pages21
JournalAstrophysical Journal
Volume703
Issue number1
DOIs
StatePublished - Jan 1 2009

Fingerprint

stars
observatory
x rays
XMM-Newton telescope
newton
census
near infrared
spectroscopy
timescale
observatories
Orion nebula
Space Infrared Telescope Facility
energy
young
spectral energy distribution
France
Canada
inspection
envelopes
infrared spectra

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Luhman, Kevin ; Mamajek, E. E. ; Allen, P. R. ; Cruz, K. L. / An infrared/x-ray survey for new members of the taurus star-forming region. In: Astrophysical Journal. 2009 ; Vol. 703, No. 1. pp. 399-419.
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An infrared/x-ray survey for new members of the taurus star-forming region. / Luhman, Kevin; Mamajek, E. E.; Allen, P. R.; Cruz, K. L.

In: Astrophysical Journal, Vol. 703, No. 1, 01.01.2009, p. 399-419.

Research output: Contribution to journalArticle

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