A new young stellar cluster embedded in a molecular cloud in the far outer Galaxy ^*,**

¹ Universidade de Lisboa – Faculdade de Ciências, Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa, Tapada da Ajuda, 1349-018 Lisboa, Portugal e-mail: yun@oal.ul.pt
² Departament d'Astronomia i Meteorologia, Facultat de Física, Planta 7a, Universitat de Barcelona, Avenida Diagonal 647, 08028 Barcelona, Spain e-mail: alopezse13@fis.ub.edu
³ Instituto de Ciencias del Espacio (CSIC) and Institut d'Estudis Espacials de Catalunya, Facultat de Física, Planta 7a, Universitat de Barcelona, Avenida Diagonal 647, 08028 Barcelona, Spain e-mail: torrelles@ieec.fcr.es

Received: 29 March 2007
Accepted: 16 May 2007

Abstract

Aims.We report the discovery of a new young stellar cluster and molecular cloud located in the far outer Galaxy, seen towards IRAS 06361-0142, and we characterise their properties.

Methods.Near-infrared images obtained with VLT/ISAAC through s filters, millimetre line observations of CO(1-0) obtained with SEST, and VLA 6 cm continuum maps obtained from archive data.

Results.The cloud and cluster are located at a distance of 7 kpc and a Galactocentric distance of 15 kpc, well in the far outer Galaxy. Morphologically, IRAS 06361-0142 appears as a cluster of several tens of stars surrounded by a nearly spherical nebular cavity centred at the position of the IRAS source. The cluster appears composed of low and intermediate-mass, young reddened stars with a large fraction having cleared the inner regions of their circumstellar discs responsible for (s) colour excess. The observations are compatible with a 4 Myr cluster with variable spatial extinction between A_v=6 and A_v=13.