GS263-02+45: a new HI supershell with evidence of having triggered star formation?

¹ Instituto Argentino de Radioastronomía (IAR), C.C. No. 5, 1894 Villa Elisa, Argentina e-mail: arnal@iar.unlp.edu.ar
² Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, 1900 La Plata, Argentina
³ Instituto de Astrofísica de La Plata (IALP), CONICET, Argentina

Received: 7 May 2007
Accepted: 17 August 2007

Abstract

Aims.We look for galactic neutral hydrogen (Hi) supershells likely to be associated with massive star groupings.

Methods.A neutral hydrogen (Hi) line survey carried out at the Instituto Argentino de Radioastronomía (IAR) and the Southern Galactic Plane Survey (SGPS) were the main databases used in this investigation.

Results.A new Hi supershell (GS263-02+45) was found in the outer part of the Galaxy. This structure is located at a distance of 5.3 ± 1 kpc from the Sun and has a linear diameter of about 665 ± 40 pc. The expansion velocity of the supershell is ~14 km s^-1. The total amount of atomic gas related to GS263-02+45 is ~2  10⁶ . Based on the analysis of the SGPS Hi data it is concluded that the OB-association Bochum 7 is likely to be interacting with GS263-02+45. This fact together with distance and age arguments may indicate that Bochum 7 was born as a consequence of the evolution of GS263-02+45.