Rapid mapping of the sky at 240 MHz using the antennas of the Giant Metrewave Radio Telescope |
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| Authors: | S K Sirothia |
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| Institution: | National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Post Bag 3, Ganeshkhind, Pune 411007, India |
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| Abstract: | In this paper we describe a method for measuring the effective receiver temperature T erc and its variation for the entire receiver chain of a radio telescope, and use it to make a radio-continuum map of the sky at 240 MHz using the Giant Metrewave Radio Telescope (GMRT). We also show that in the case of GMRT, T erc varies mainly with elevation and ambient temperature. The calibration techniques evolved here are applicable to similar interferometers with a large number of antennas, several frequency bands and a number of receiver systems at room temperature (where conventional methods are time-consuming). This method ideally requires just one complete day of observations in a frequency band. |
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| Keywords: | instrumentation: miscellaneous methods: observational surveys Galaxy: structure radio continuum: galaxies |
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