Upgraded GMRT Observations of the Coma Cluster of Galaxies: The Observations

Abstract

We have used the upgraded Giant Metrewave Radio Telescope to map the Coma cluster of galaxies at 250–500 MHz and 1050–1450 MHz bands. These 6.″26 and 2.″18 resolutions observations allow detailed radio structures to be determined of all detected radio sources that show both discrete pointlike and extended morphologies. We present images of a subset of 32 brightest ( S ν ≳ 30 mJy) and dominant sources, and several sources show discrete pointlike radio morphologies. We find the steepening of the spectra consistent with synchrotron cooling in the majority of sources and the median for spectral indices is −0.78, suggesting that ∼59% sources have steep spectra. The nature and the statistical properties of the radio sources in the Coma cluster will be discussed in subsequent papers.