Star formation in the vicinity of the IC 348 cluster

¹ Observatorio Astronómico Nacional (IGN), Alfonso XII 3, E-28014 Madrid, Spain e-mail: m.tafalla@oan.es
² Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal

Received: 26 April 2006
Accepted: 23 May 2006

Abstract

Aims.We present molecular line observations of the southwestern part of the IC 348 young cluster, and we use them together with NIR and mm continuum data to determine the distribution of dense gas, search for molecular outflows, and analyze the ongoing star formation activity in the region.

Methods.Our molecular line data consists of C¹⁸O(1–0) and N₂H⁺(1–0) maps obtained with the FCRAO telescope at a resolution of about and CO(2–1) data obtained with the IRAM 30 m telescope at a resolution of .

Results.The dense gas southwest of IC 348 is concentrated in two groups of dense cores, each of them with a few solar masses of material and indications of CO depletion at high density. One of the core groups is actively forming stars, while the other seems starless. There is evidence for at least three bipolar molecular outflows in the region, two of them powered by previously identified Class 0 sources while the other is powered by a still not well characterized low-luminosity object. The ongoing star formation activity is producing a small stellar subgroup in the cluster. Using the observed core characteristics and the star formation rate in the cluster, we propose that similar episodes of stellar birth may have produced the subclustering seen in the halo of IC 348.