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| RG Research: Galactic Structure | ||||
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While our optical view of the Milky Way is limited by interstellar dust to just a modest fraction of the distance across the Galactic disk, at radio wavelengths emissions from interstellar gas in its various forms can be readily observed throughout the Galaxy. For this reason, radio astronomers have played a leading role in Galactic structure research since the 1950s, when the first large-scale 21 cm surveys of interstellar atomic hydrogen were carried out. RG astronomers use the CfA millimeter-wave telescope to obtain very large-scale surveys of the distribution of dense, star-forming molecular gas in the Galaxy, and they are pioneering the use of interstellar masers to map out the spiral structure of the Galaxy, determine the distance to the Galactic center, and study the Galaxy's large-scale magnetic field structure. Project Links
Spiral Structure and Kinematics People |
A map of the angular distribution and kinematics of dense molecular gas in the Galactic plane within 60 degrees of the Galactic center. Owing to Galactic rotation, the gas is predominately moving away from us (positive velocities) on one side of the Galactic center (positive longitudes) and towards us on the other side. The prominent spike near 0 degrees longitude arises from dense gas expanding rapidly away from the Galactic center region, perhaps owing to a past episode of outburst activity by our Galaxy's central black hole. Other quasi-linear features in the map trace Galactic spiral arms. Image credit: Dame, Hartmann, & Thaddeus (2001) | ||
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