Newly discovered candidate weak-line T Tauri stars in the surrounding area of the Taurus-Auriga region
Abstract
We present results of an extensive search for weak-line T Tauri stars (WTTS) in the outskirts of the Taurus-Auriga molecular cloud on the basis of the ROSAT All-Sky Survey Bright Source Catalog. Our surveyed region extends from 2() h40() m to 5() h40() m in right ascension and from 10(deg) to 40(deg) in declination, with the central part of Taurus-Auriga (4() h<alpha < 5() h, 15(deg) <delta < 34(deg) ), accomplished by \cite[Wichmann et al. (1996)]{wi96}, excluded. Within a sky coverage of about 10(3) square degrees, 219 X-ray sources fulfil the criteria for selecting program sources suggested by \cite[Neuhaeuser et al. (1995a)]{ne95a}, and 164 of these X-ray sources were found to have at least one optical counterpart with E magnitude brighter than 16. Low-resolution spectroscopic observation has been carried out in order to discard early type stars and galaxies from the sample, additional intermediate-resolution spectra of a sub-sample of 156 late type optical counterparts were obtained for spectral classification and for the calculation of the equivalent width of H_α emission and LiI line absorption at 6707 Angstroms. Excluding 2 previously identified WTTS, a total of 75 new candidate WTTS and one possible classical T Tauri star have been discovered in our study. The majority of the newly found Li-rich optical counterparts are believed to be PMS stars rather than ZAMS stars as those of the Pleiades. Tables 2-5 are also available in electronic form at the CDS via anonymous ftp 130.79.128.5 or via http://cdsweb.u-strasbg.fr/Abstract.html
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- October 1998
- DOI:
- 10.1051/aas:1998288
- Bibcode:
- 1998A&AS..132..173L
- Keywords:
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- STARS: FORMATION;
- STARS: PRE-MAIN SEQUENCE;
- X-RAY: STARS;
- SURVEYS