Low radio frequency spectrum of Sgr-A*

AbstractWe observed the Galactic centre (GC) region with the partially upgraded Giant Metrewave Radio Telescope (GMRT) using a wideband system in frequency ranges of 300– 500 MHz with 16 antennas. Preliminary results are presented here. Sgr-A* is clearly detected down to 450 MHz. Sgr-A West slowly disappears at lower frequencies across the band. By taking cross-cuts across the known major-axis of Sgr-A*, we measure its total flux density across the band to be 0.4 Jy consistent with what is expected from earlier results. It clearly indicates lack of absorption from Sgr-A West. Its spectral index is consistent with its higher frequency value of +0.3.