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

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 M. 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.