Abstract Details
| Name: Subhashis Roy Affiliation: NCRA-TIFR Conference ID: ASI2016_957 Title : Nature of a transient source near Galactic centre Authors and Co-Authors : Sabyasachi Pal (ICSP) Abstract Type : Poster Abstract Category : Stars, The Milky Way Galaxy and its neighbours Abstract : From our observations of a region about a degree away from the Galactic Centre with the GMRT about a decade back, we report discovery of a small angular sized source which has been found to be in the on and off state in time scale of a few years. This object G359.1+1.0 is seen within the supernova remnant G359.1+0.9. From our 325 and 610 MHz observation with the GMRT, its spectral index is found to be steep. Its measured value is -0.9 +/- 0.2. Its flux density at 325 MHz is about 50 mJy and is extended along North-South with an angular size of 30"x10". However, this source is undetected in the NRAO VLA sky survey (NVSS) at 1.4 GHz, the observation for which was sometime between 1993-1996 implying the source was more than a factor of 5 fainter than expected based on its metre wavelength spectral index. From the archival Very Large Array data, this source was not detected in 1984 at 1.6 GHz, but is detected in October 1990 at the same frequency. From these observations, we find the shortest variability timescale of about 5 years. Equating it to the ratio of source size to the velocity of light, indicates the object is of size about 1 pc. Considering its angular size, the distance of this object is ~11 kpc, indicating it to be Galactic in origin. We argue that this object is unlikely to be a pulsar, pulsar wind nebula, radio star, Herbig-Haro object or part of any supernova remnant. This source could be a newly detected microquasar. |