1997A&A...324L...5C

Massive, large scale star counts in the J (1.25µm) band provided by the Deep Near Infrared Survey of the Southern Sky (DENIS) are used for the first time to draw out an extinction map of the Chamaeleon I dark cloud. We derived a 2' resolution map of the cloud from J star counts within an area of 1.5°x3° around the centre of the cloud using an adaptive grid method and applying a wavelet decomposition. Possible contaminating young stellar objects within the cloud are removed, although they are shown to have a negligible effect on the counts. A comparison of our extinction map with the cold contribution of the IRAS 100µm emission shows an almost perfect matching. It is shown that J star counts supersede optical counts on Schmidt plate where A_V>4.