The WSRT 327 MHz Galactic Plane Survey

The Westerbork Synthesis Radio Telescope (WSRT) in the Netherlands was used to survey a section of the galactic plane at a radio frequency of 327MHz.Twenty-three overlapping fields were observed, covering galactic co-ordinates |b|<2.5d, 42d < l < 92d. Each field was observed at two epochs, several years apart, to identify variable sources. Observations were made in all four Stokes parameters, enabling polarization analysis. Intensity data from the seperate epochs were combined, and the resulting images mosaiced to produce a single image of the entire survey region. Sensitivity varies from roughly 10 mJy along the center of the image (b=0d) to roughly 150 mJy along the edges (b=+-2.5d). Resolution is 1' by 1'csc(dec).

The survey image provides our first high resolution view of the Galaxy at low frequencies, and includes sections of the Sagittarius and Cygnus arms. These sections correspond to areas with numerous extended features, among them supernova remnants, HII regions, "bubbles" of thermal emission, and large patches of amorphous galactic thermal emission. The inter-arm region is characterized by low densities of extended features. most of which are background objects such as quasars and other types of active galactic nuclei.

The resolution, sensitivity and low frequency pf this survey make it ideal for detecting weak, non-thermal galactic sources, e.g. low surface brightness SNRs and radio stars. Extensive analysis of the survey data is ongoing, and this analysis is being undertaken by James van Leeuwen (jvl@ras.ucalgary.ca)(compact objects) and Brad Wallace (brad@ras.ucalgary.ca)(extended objects).

The image above is from the WSRT 327MHz survey and shows the region around the HC40 supernova remnant. Images of the entire survey region can be found by clicking on each button

Image of Galactic Longitude range 77 to 84 degrees. [188613 bytes]

Image of Galactic Longitude range 70 to 77 degrees. [147614 bytes]

Image of Galactic Longitude range 63 to 70 degrees. [124132 bytes]

Image of Galactic Longitude range 57 to 64 degrees. [132850 bytes]

Image of Galactic Longitude range 50 to 57 degrees. [164930 bytes]

Image of Galactic Longitude range 43 to 50 degrees. [201557 bytes]