Near-infrared and ISOCAM observations of the Chamaeleon II dark cloud

An infrared study including ISOCAM images at 6.75 and 14.3 mum of a large portion (28'x26') of the Chamaeleon II dark cloud and sub-arcsec resolution JHK(s) images of the central (4.9'x4.9') area is presented. Combining the ISOCAM observations with J and K-s 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 similar to0.02 L-circle dot and a stellar luminosity greater than or equal to0.01 L-circle dot. 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 J-H/H-K 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 L-bol=1.49 L-circle dot and associated with a faint nebulosity observed at 2.2 mum.