2MASS J11050025-7721463 , the SIMBAD biblio

We present an analysis of point sources discovered by DENIS in an area of ≃1.5degx3deg around the Chamaeleon I molecular cloud. Most of the 30000 objects detected in the J band are background stars that were previously used to derive an accurate extinction map of the full area (Cambresy et al., 1997A&A...324L...5C) using star counts. Here, we investigate the young stellar population of the cloud using the IJK_s photometric DENIS data. The whole sample of 126 already known YSOs, which are mainly T Tauri stars, are identified in the DENIS catalogue. Besides, we propose 54 sources as new candidates of YSOs. These new faint objects are selected according to their extremely red near infrared colour, that cannot be explained only by the reddening of the cloud. Moreover they are concentrated near the most obscured areas of the cloud. Pending spectroscopic measurements, the sources are interpreted as probable classical T Tauri stars that have escaped previous spectroscopic, IRAS or X-ray observations and pertaining to the low-end of the luminosity function. Assuming that they are reliable YSOs with massive accretion disks, and using theoretical pre-main-sequence tracks we estimate the age of this sample to be ranging from 5x10⁵ to 4x10⁶ years, an elapse of time that spans the range between the end of the star formation in the cloud and the maximum life time of the circumstellar disk.