Letter to the Editor

Evidence of triggered star formation in G327.3-0.6

Dust-continuum mapping of an infrared dark cloud with P-ArTéMiS

¹ Laboratoire AIM, CEA Saclay-Université Paris Diderot-CNRS, DSM/Irfu/Service d'Astrophysique, 91191 Gif-sur-Yvette, France e-mail: vincent.minier@cea.fr
² Onsala Space Observatory, Chalmers University of Technology, 439 92 Onsala, Sweden
³ European Southern Observatory, Casilla 19001, Santiago 19, Chile
⁴ Max Planck Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
⁵ Institut d'Astrophysique de Paris, UPMC (Université Paris 6), 98b Bd Arago, 75014 Paris, France

Received: 8 April 2009
Accepted: 18 May 2009

Abstract

Aims. Expanding HII regions and propagating shocks are common in the environment of young high-mass star-forming complexes. They can compress a pre-existing molecular cloud and trigger the formation of dense cores. We investigate whether these phenomena can explain the formation of high-mass protostars within an infrared dark cloud located at the position of G327.3-0.6 in the Galactic plane, in between two large infrared bubbles and two HII regions.

Methods. The region of G327.3-0.6 was imaged at 450 μm with the CEA P-ArTéMiS bolometer array on the Atacama Pathfinder EXperiment telescope in Chile. APEX/LABOCA and APEX-2A, and Spitzer/IRAC and MIPS archives data were used in this study.

Results. Ten massive cores were detected in the P-ArTéMiS image, embedded within the infrared dark cloud seen in absorption at both 8 and 24 μm. Their luminosities and masses indicate that they form high-mass stars. The kinematical study of the region suggests that the infrared bubbles expand toward the infrared dark cloud.

Conclusions. Under the influence of expanding bubbles, star formation occurs in the infrared dark areas at the border of HII regions and infrared bubbles.