Released 10:00 a.m. CST Jan. 8, 1999
at the American Astronomical Society meeting in Austin, Texas

Copyright: The following materials are copyrighted by the Canadian Galactic Plane Survey/Releve Canadien du Plan Galactique (CGPS/RCPG). They are intended as a news release and for use for educational, academic, and research purposes and are not intended for commercial sale.
Please contact Jayanne English ((204)-474-7105; email:

An Atomic Hydrogen Mushroom Cloud Bursts out of our Galaxy

New radio images catch a mushroom-shaped gas cloud bursting over 1,000 light-years out of the disk of our Milky Way galaxy, propelled by the power of 500 suns. These observations provide the first detailed view of the gas columns which appear to link the disk with altitudes high in our galaxy's atmosphere. They will help reveal how heat, radiation, dust, and gas could all rise away from their cradles, which are in clusters of igniting and dying stars, and in doing so contribute to the formation of our galaxy's hot gas halo. Although theories exist which model the chimney-like behaviour of gas column clouds, the preliminary measurements from these Dominion Radio Astrophysical Observatory (DRAO) images challenge these current scenarios.

Credit: Drs. Jayanne English (University of Manitoba; formally of Queen's University), Russ Taylor (University of Calgary), Judith Irwin (Queen's University), and Sergey Mashchenko (University of Laval) of the Canadian Galactic Plane Survey/Releve Canadien du Plan Galactique (CGPS/RCPG).

Text of Full Press ReleasePlain Text VersionLatex Formated VersionPostscript Version
Figure 1: The Mushroom Cloud35 Kbyte Jpeg

Colour for Sun Monitor's: jpeg

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Colour for Mac Monitors: jpeg

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Colour for Mac Monitors: tiff

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Figure 2: Mushroom-Shaped Supershell Scenario44 Kbyte Jpeg

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Unlabeled postscript figure (~800 Kbytes)

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Labeled jpeg figure

Labeled postscript figure (~900 Kbytes)

Figure 2. Caption Plain Text VersionLatex Formated VersionPostscript Version

Note that the labeled Figure 2. was used as part of the caption for the unlabeled Figure2.

Black and Whites:

The image below links to an illustration of the difference in scale between predicted mushroom-shaped clouds and the observed cloud. The scale of the outline of a blowout model by Tenorio-Tagle, Rozyczka, and Bodenheimer (1990) is almost 4x that in the observed data.

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Jpeg figure with labels

The images below link to black and white Jpeg images of the integrated intensity over the FWHM of the observed HI data.

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If you have any other questions or comments, contact Jayanne English.