The central region of the Galaxy has been observed at 580 , 620 and 1010 MHz with the Giant Metrewave Radio Telescope ( GMRT ) .
We detect emission from Sgr A* , the compact object at the dynamical centre of the Galaxy , and estimate its flux density at 620 MHz to be 0.5 \pm 0.1 Jy .
This is the first detection of Sgr A* below 1 GHz ( ) , which along with a possible detection at 330 MHz ( ) provides its spectrum below 1 GHz .
Comparison of the 620 MHz map with maps made at other frequencies indicates that most parts of the Sgr A West HII region have optical depth \sim 2 .
However , Sgr A* , which is seen in the same region in projection , shows a slightly inverted spectral index between 1010 MHz and 620 MHz .
This is consistent with its high frequency spectral index , and indicates that Sgr A* is located in front of the Sgr A West complex , and rules out any low frequency turnover around 1 GHz , as suggested by ( ) .