GMRTLHCAT2 - Giant Metrewave Radio Telescope Lockman Hole 610-MHz Radio Source Catalog 2
The earlier survey had 12 pointings covering ~ 5 square degrees in the center of the Lockman Hole, and herein a further 26 pointings in the outer parts of the Lockman Hole are added, to cover a total of ~ 14 square degrees. To match the earlier survey, the images were made with a resolution of 6" x 5", at a position angle of +45 degrees. The majority of the new pointings have an rms noise of ~80 uJy/beam before the primary beam correction, but the noise in the west - particularly near the very bright source 3C244.1 - is worse.
Further GMRT observations of the Lockman Hole at 610 MHz. Garn T.S., Green D.A., Riley J.M., Alexander P. <Bull. Astron. Soc. India, 38, 103-112 (2010)> =2010BASI...38..103G (SIMBAD/NED BibCode)
The name of the radio source using the IAU-style designation for the source based on the truncated J2000.0 equatorial coordinates of its centroid, viz., 'GMRTLH JHHMMSS.s+DDMMSS', as registered with the CDS Dictionary of Nomenclature of Celestial Objects, where the GMRTLH prefix stands for 'Giant Metrewave Radio Telescope Lockman Hole'.
The Right Ascension of the source in the selected equinox, calculated using first moments of the relevant pixel brightnesses to give the centroid position. This was given in J2000.0 coordinates to a precision of 0.01 seconds of time in the original table.
The Declination of the source in the selected equinox, calculated using first moments of the relevant pixel brightnesses to give the centroid position. This was given in J2000.0 coordinates to a precision of 0.1 arcseconds in the original table.
The Galactic Longitude of the radio source centroid.
The Galactic Latitude of the radio source centroid.
The radio brightness of the peak pixel in the 610-MHz radio source, in mJy/beam.
The local rms noise near the source position, in mJy/beam (converted by the HEASARC from the uJy/beam units used in the original table).
The integrated flux density of the 610-MHz radio source, in mJy.
The error in the integrated flux density of the 610-MHz radio source, in mJy.
The X pixel coordinate from the mosaic image which was closest to the source centroid.
The Y pixel coordinate from the mosaic image which was closest to the source centroid.
The SEXTRACTOR (Source Extractor) deblended object flag coded as follows:
1 = where a nearby bright source may be affecting the calculated flux 2 = where a source has been deblended into two or more components from a single initial 'island' of flux 3 = when both conditions 1 and 2 applyThere are 226 sources present in the catalog with non-zero deblend flags, and it is necessary to examine the GMRT mosaic image, available at http://www.mrao.cam.ac.uk/surveys/GMRT/LH/, to distinguish between the case where one extended object has been represented by 2 or more entries, compared to the case where two astronomically different objects are actually present.