Near–infrared and ISOCAM observations of the Chamaeleon II dark cloud ^*,**

¹ Istituto Astrofisica Spaziale e Fisica Cosmica, CNR, via del Fosso del Cavaliere, 00133, Roma, Italy e-mail: persi@rm.iasf.cnr.it
² Observatorio Astronómico de Córdoba, Laprida 854, 5000 Córdoba, Argentina
³ Stockholm Observatory, SCFAB, 106 91 Stockholm, Sweden

Corresponding author: P. Persi, persi@rm.iasf.cnr.it

Received: 3 October 2002
Accepted: 3 December 2002

Abstract

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 JHK_s images of the central (4.9´  4.9´) 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 ~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 .