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Evidence for chimney breakout in the Galactic supershell GSH 242-03+37

N. M. McClure-Griffiths·A. Ford·D. J. Pisano·B. K. Gibson·L. Staveley-Smith·M. R. Calabretta·L. Dedes·P. M. W. Kalberla
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Abstract

We present new high resolution neutral hydrogen (H I) images of the Galactic supershell GSH 242-03+37. These data were obtained with the Parkes Radiotelescope as part of the Galactic All-Sky Survey (GASS). GSH 242-03+37 is one of the largest and most energetic H I supershells in the Galaxy with a radius of $565 \pm 65$ pc and an expansion energy of 3x10^{53} ergs. Our images reveal a complicated shell with multiple chimney structures on both sides of the Galactic plane. These chimneys appear capped by narrow filaments about 1.6 kpc above and below the Galactic mid-plane, confirming structures predicted in simulations of expanding supershells. The structure of GSH 242-03+37 is extremely similar to the only other Galactic supershell known to have blown out of both sides of the plane, GSH 277+00+36. We compare the GASS H I data with X-ray and H-alpha, finding no strong correlations.

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N. M. McClure-Griffiths, A. Ford, D. J. Pisano, B. K. Gibson, L. Staveley-Smith, M. R. Calabretta, L. Dedes, P. M. W. Kalberla. 2005-10-11. Evidence for chimney breakout in the Galactic supershell GSH 242-03+37. https://doi.org/10.1086/498706

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