The new HI supershell GS262-02+45 and the OB Association Bochum 7 ......close relatives?

CORTI, MARIELA ALEJANDRA; ARNAL, EDMUNDO MARCELO

Carilo, Buenos Aires, Argentina

Workshop; Massive Stars: Fundamental Parameters and Circumstellar Interactions; 2006

The neutral hydrogen (HI) supershells are among the mostspectacular phenomena that can be witnessed in the interstellar mediumof spiral galaxys. The HI supershells are often identified as a HIbrightness temperature minimun surrounded by "walls" of HI emission. In this work we present observational results that reveal the presenceof a new HI supershell in a complex region of theMilky Way. Following the nomenclature accepted to designate these objets, the new HI supershell has been identified as GS262-02+45 andits diameter is of the order of 630 pc at a distance of  ~ 5 kpc.In this work we determined itsphysical characteristic (mass, expansion velocity, mean volume, density) and correlate the large scale distribution of the HI with the onecorresponding to the dust (MSX and IRIS databases). We discuss thepossibility that the OB associationhas formed by the supershell some (2-7) x 10e(6) years ago.