Astron. Astrophys. 324, L5-L8 (1997)

Letter to the Editor

Extinction map of Chamaeleon I molecular cloud with DENIS star counts ^*

L. Cambrésy ¹, N. Epchtein ¹, E.Copet ¹, B. de Batz ¹, S. Kimeswenger ², T. Le Bertre ¹, D. Rouan ¹ and D. Tiphène <sup>1

1</sup> Observatoire de Paris, CNRS URA 264 and URA 335, F-92195 Meudon Cedex, France
² Institut für Astronomie der Leopold-Franzens-Universität Innsbruck, Technikerstraße 25, A-6020 Innsbruck, Austria

Received 3 April 1997 / Accepted 1 May 1997

Abstract

Massive, large scale star counts in the J (1.25 ) 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 resolution map of the cloud from J star counts within an area of 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 emission shows an almost perfect matching. It is shown that J star counts supersede optical counts on Schmidt plate where .

Key words: ISM: clouds ISM: dust, extinction ISM: individual objects: Chamaeleon

* Based on observations collected at the European Southern Observatory, La Silla, Chile

Send offprint requests to: Laurent Cambresy, Cambresy@denisezg.obspm.fr

© European Southern Observatory (ESO) 1997

Online publication: May 26, 1998

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