GMRTLHCAT - Giant Metrewave Radio Telescope Lockman Hole 610-MHz Radio Source Catalog
The 'central region' of the Lockman Hole, consisting of 12 pointings spaced by 36 arcminutes in a hexagonal pattern (shown in Fig. 1 of the reference paper) was observed on 2004 July 24 and 25 using the GMRT. The observations were made in two 16-MHz sidebands centred on 610 MHz, each split into 128 spectral channels, with a 16.9s integration time.
A 610-MHz survey of the Lockman Hole with the Giant Metrewave Radio Telescope. I. Observations, data reduction and source catalogue for the central 5 deg2. Garn T., Green D.A., Riley J. M., Alexander P. <Mon. Not. R. Astron. Soc. 387, 1037 (2008)> =2008MNRAS.387.1037G
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 77 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.