Search for young low-mass stars in a ROSAT selected sample south of the Taurus-Auriga molecular clouds *,**
Osservatorio Astrofisico di Catania, Città Universitaria, I-95125 Catania, Italy
2 Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife, Spain
3 Max-Planck-Institut für Extraterrestrische Physik, D-85740 Garching, Germany
4 Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli, Italy
Accepted: 3 December 1996
We present results of intermediate resolution spectroscopy of 131 optical counterparts to 115 ROSAT All-Sky Survey X-ray sources south of the Taurus-Auriga dark cloud complex. These objects have been selected as candidate young stars from a total of 1084 ROSAT sources in a square degree area. We identify 30 objects as low-mass PMS stars on the basis of the Li i doublet in their spectrum, a signature of their young age. All these stars have a spectral type later than F7 and show spectral characteristics typical of weak-line and post-T Tauri stars. The presence of young objects several parsecs away from the regions of ongoing star formation is discussed in the light of the current models of T Tauri dispersal.
Key words: stars: formation / stars: late-type / stars: pre-main sequence / X-rays: stars
Based on observations made with the Isaac Newton Telescope operated on the island of La Palma by the Royal Greenwich Observatory in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias and with the ESO 1.52m telescope on La Silla, Chile, operated by the European Southern Observatory.
Tables 1, 2, 3, 4 are also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (220.127.116.11) or via http://cdsweb.u-strasbg.fr/Abstract.html
© European Southern Observatory (ESO), 1997