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Session 6 - The ISM & Molecular Clouds.
Display session, Monday, June 09
South Main Hall,

[6.07] Observations of HI Associated with the W4 Supershell

J. H. Simonetti, G. A. Topasna, B. Dennison (Virginia Tech), E. M. Murphy (Johns Hopkins), F. J. Lockman (NRAO)

From HI observations, Normandeau, Taylor, and Dewdney identified a possible Galactic chimney emanating upward from the HII region W4 to a Galactic latitude of about 4^\circ (about 3^\circ up from OCl 352, the very young star cluster which excites W4). We have observed the region using a wide-field CCD camera sensitive to extended H\alpha emission (the Virginia Tech Spectral Line Imaging Camera), and detected an H\alpha supershell which apparently closes at about 6^\circ above OCl 352. Here we present 21cm observations we made of the region using the 43m radio telescope at Green Bank. Virtually all of the features in the H\alpha image have corresponding HI features at a velocity near that of the low-latitude structure seen by Normandeau, Taylor, and Dewdney. Therefore, these observations are consistent with the conclusion of our H\alpha study: there is a supershell above W4 which is apparently closed. This research was supported by NSF grant AST-9319670 and a grant from the Horton Foundation to Virginia Tech.

Program listing for Monday