Low radio frequency spectrum of Sgr-A*
Abstract
We 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.
- Publication:
-
The Multi-Messenger Astrophysics of the Galactic Centre
- Pub Date:
- January 2017
- DOI:
- Bibcode:
- 2017IAUS..322...54R
- Keywords:
-
- Galaxy: center-radio continuum: ISM-H II regions