VLA Sky Survey Quick Look Images

Quick Look image products are 1x1 degree images of the 2-4GHz Stokes I continuum, and an associated image of the RMS.

Images are grouped by tiles, as described at Tile Definitions and Observing Status, and individual images are are named as follows:

• VLASS epoch (1.1=first half of first epoch; 1.2=second half of first epoch; 2.1=first half of second epoch, etc.)
• Product type (ql=Quick Look imaging)
• Tile name
• Image phase center
• Pixel size x10 (10=1.0arcsec)
• Bandwidth in MHz
• Version number
• Stokes type

These directories contain the Quick Look images for the Pilot, VLASS1.1 and VLASS1.2 observing campaigns. In addition, the Test directory contains QA rejected images and miscellaneous tests, and the old_image_versions directory contains deprecated versions of the images.

The Quick Look images were made using a simplified imaging algorithm that does not correct for wide-field effects, resulting in significant positional and flux density errors, as well as poor image quality compared to a typical pointed observation with the VLA. Before using these images for scientific purposes, the Users' Guide to Quick Look images should be consulted.