Inside the large globule CB205: YSOs feeding multiple outflows

¹ INAF - Istituto di Radioastronomia, Sezione di Firenze, Largo E. Fermi 5, 50125 Firenze, Italy e-mail: codella@arcetri.astro.it
² INAF - Istituto di Radioastronomia, via Gobetti 101, 40129 Bologna, Italy
³ INAF - Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
⁴ Joint Astronomy Centre, 660 N. A'ohoku Place, University Park, Hilo, HI 96720, USA

Received: 13 April 2006
Accepted: 27 June 2006

Abstract

Context.The molecular and continuum surveys at NIR and (sub-)mmwavelengths recently performed in the large and distant (≥1 kpc) Bok globules CB3 and CB34 are the framework of the present paper. With this multi-wavelength approach, it is possible to trace the hot jets and cold outflows driven by the (proto-)stars, to investigate how they interact with the surrounding medium, and to assess that in these globules star formation is a continuous process and not a unique event.

Aims.With the present work we continue our survey of a sample of large globules by investigating CB205. The aim is to carefully map the outflow motions and to locate the driving sources. The occurrence of outflows is used to identify the earliest star-forming regions.

Methods.Our analysis has been performed through JCMT observations at (sub)millimeter wavelengths of the continuum (850 and 450 μm) and CO(2–1) and (3–2) line emission.

Results.The continuum maps reveal three Class 0 candidates located in the western region of the globule, without NIR counterparts. The line maps show a complex scenario for the high velocity components with different clumps at different velocities. The outflow activity is concentrated around the Class 0 candidates. On the other hand, the NIR objects are associated with lower velocity outflow clumps.

Conclusions.The present results confirm that for CB205, star formation is propagating through the globule. The western part hosts the latest formation episode with Class 0 candidates feeding multiple outflows. We suggest that the eastern region, which is associated with a NIR cluster, reflects a later evolutionary phase, when the outflow is fading.