VLSS Postage Stamp Server (2001.12.06)

The VLA Low-Frequency Sky Survey

VLSS Postage Stamp Server

This postage Stamp server for the VLA Low-Frequency Sky Survey (VLSS, formerly 4MASS ) returns radio images of the sky in FITS or JPEG format, or as a contour plot. For detailed general instructions or information about this survey, see the Help File under "general"; or use the links on the forms for help about each item.

The VLSS survey is being carried out by the NRAO and the Naval Research Lab.

Equinox:
Object name [optional]:
Central Right Ascension:
Central declination:
Desired image size (degrees): See Pixel Spacing for size limit.
Pixel spacing: Desired pixel size in arcseconds (Min 0.001; max image size 262144 pixels, e.g. 512 x 512)
Projection:
Desired rotation (N through E) on the sky in degrees. (Use 0.0 for contour plots)
Image Type: Don't use "FITS Image" unless you have an external viewer configured to activate for fits files in your browser. Also, for JPEG images, you may need to "reload" the image if you've fetched more than one.

Note: The VLSS survey is not yet complete.

Note: these images will have a relatively high dynamic range which will cause them to appear as white dots on a black background unless the viewer used has suitable control over brightness, contrast and the range of values to be displayed. The "noise" level in these images is about 100 mJy/beam.

Entire 14 x 14 deg fields can be obtained here or through a simplified form interface. The entire source catalog as a FITS binary table and software here. (Reminder: shift-click will generally force your browser to save the requested image to a file rather than displaying it in a text window.) A catalog browser server is also available to lookup positions in the catalog.

the FITSview family of FITS image viewers is available for a variety of computer systems. For a short discussion of installing external viewers for FITS files click here.

Publication info.

Other Sources of FITS Images from Sky Surveys

The (USA) National Radio Astronomy Observatory (NRAO) is operated by Associated Universities, Inc. and is a Facility of the (USA) National Science Foundation.

Comments? Questions? Problems?