Istituto Astrofisica Spaziale e Fisica Cosmica, CNR, via del Fosso del Cavaliere, 00133, Roma, Italy e-mail: email@example.com
2 Observatorio Astronómico de Córdoba, Laprida 854, 5000 Córdoba, Argentina
3 Stockholm Observatory, SCFAB, 106 91 Stockholm, Sweden
Corresponding author: P. Persi, firstname.lastname@example.org
Accepted: 3 December 2002
An infrared study including ISOCAM images at 6.75 and 14.3 of a large portion (28´ 26´) of the Chamaeleon II dark cloud and sub-arcsec resolution JHKs images of the central (4.9´ 4.9´) area is presented. Combining the ISOCAM observations with J and Ks photometry obtained with DENIS, we have found 12 young stars, of which 8 are previously identified sources. Of the new candidate YSOs, ISO-ChaII13 shows a clear mid–IR excess with an infrared luminosity of ~0.02 and a stellar luminosity ≥0.01 . This last value of luminosity corresponds to that expected for a sub–stellar object with an age between 1–10 Myr. The analysis of the / diagram of the sources detected in the central part of the dark cloud has allowed us to identify 10 very faint sources not found by ISOCAM with possible near-IR excesses that may be embedded young brown dwarfs. Finally, the center of the dark cloud is characterized by the presence of the Class I YSO IRAS 12553–7651 (ISO-ChaII28) with 1.49 , and associated with a faint nebulosity observed at 2.2 .
Key words: stars: formation / stars: low-mass, brown dwarfs / stars: pre-main sequence / infrared: stars
Based on observations collected at the European Southern Observatory, Chile, ESO proposal N.65.I-0054, CTIO(Chile), and ISOCAM observations N.11500619, and 11500620.
© ESO, 2003