GS234-02: A Star Forming Supershell in the Outer Galaxy

Abstract

view Abstract Citations (10) References (56) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS GS234-02: A Star Forming Supershell in the Outer Galaxy Jung, Jae Hoon ; Koo, Bon-Chul ; Kang, Yong-Hee Abstract Using IRA S, COBE, CO, and H I survey data, we have studied the physical properties of an interstellar loop structure centered at (l,b) = (234°,-2°). The structure, GS234-02, appears as an almost complete loop of ∼4° radius with its northwestern half much brighter than the southeastern half in infrared (IR). We have derived the IR fluxes between 12 and 240 μm. The IR spectrum is not different from that of the general interstellar medium except for some possible excess at 12 μm. GS234-02 is composed of H II regions, molecular clouds, and atomic gas. There are two giant molecular clouds associated with GS234 - 02. H II regions are found only in one of them. The distance 4 kpc to the associated H II regions and molecular clouds implies that GS234-02 is in Perseus arm. The velocity structure in H I 21 cm emission suggests that GS234-02 is possibly a shell expanding slowly, e.g., at 10 km s-1. The large radius (280 pc) and the large kinetic energy (∼5.5×1051 ergs) then imply that GS234-02 is a supershell in the outer Galaxy. Furthermore the molecular clouds and the associated H it regions in the periphery suggest that a second generation of stars has been formed in the shell. Hence, GS234-02 could be a supershell in which self-propagating star formation is ongoing, turning it from a simple expanding shell into a detonation front. We derive the physical parameters and discuss the evolutionary history of GS234-02. Publication: The Astronomical Journal Pub Date: October 1996 DOI: 10.1086/118128 Bibcode: 1996AJ....112.1625J Keywords: STARS: FORMATION; GALAXY: STELLAR CONTENT; ISM: INDIVIDUAL: GS234-02 full text sources ADS | data products SIMBAD (18)