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Using the NVSS to set IMAGR fields in AIPS

This Web page will assist in setting fields in AIPS task IMAGR in the neighborhood of a specified position. This will help deal with confusing sources when it is not possible or desirable to image the full primary beam of the antenna. The procedure is to use the NVSS (NRAO/VLA Sky Survey) survey to select sources in the area of interest and then to produce an AIPS "RUN" file that sets the extra fields containing the confusing sources. The returned file can be either used directly as an AIPS RUN file by stripping the html wrapper or using the cut and paste facility of your window manager to enter the commands directly into AIPS.

The NVSS radio survey uses the NRAO Very Large Array telescope and covers the sky north of a declination of -40 degrees at a frequency of 1.4 GHz, a resolution of 45" and a limiting peak source brightness of about 2.5 mJy/beam. This survey is nearly complete with only a few holes remaining to be covered. For detailed general instructions click here or for more about a form entry click on its label.

Equinox: B1900 B1950 J2000
Right Ascension:
as hh mm
as (+/-)dd mm ss
Maximum radius, in arcminutes : Minimum peak flux density (mJy):
Size of CLEANed area (cells): Cell spacing (arcsec):
Antenna diameter(m): Observing Freq (MHz):
Additional Field Size (cells): First field number: Maximum fields:

Other NVSS Resources

For details on the probability of the chance coincidence of an NVSS source within a given radius of an arbitrary position look here.

In publications using NVSS results please reference Condon, et al. 1998, AJ, 115, 1693; a preprint of this paper which describes the design and techniques of the NVSS is available here. The contents of the NVSS source catalog is described here. For very extensive searches or listing of large amounts of the catalog it may be best to obtain your own copy of the catalog (about 150 MByte) and the browsing software (Unix only). For the latest information and detailed descriptions of the NVSS survey see its home page. Entire 4 x 4 degree fields may be obtained as FITS files using either a Web browser or ftp. (Reminder: shift-click will generally force your browser to save the requested image to a file rather than displaying it in a text window.) The NVSS Catalog browser will search the catalog for specified regions and return a list of sources found. A postage stamp server which returns FITS or jpeg files of limited regions from NVSS images is also available.

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

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Modified on Thursday, 13-May-2021 12:15:12 EDT