Bulletin of the Astronomical Society of India
S. Roy1* and S. Pal2,3
1NCRA-TIFR, Pune, India
2Indian Centre for Space Physics, Kolkata 700 084, India
3Ionospheric and Earthquake Research Centre, Sitapur 721154, India
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We have discovered a shell like structure G354.4+0.0 of size 1.6' which shows the morphology of a shell supernova remnant. Part of the structure show polarized emission in NRAO VLA sky survey (NVSS) map. Based on 330 MHz, 1.4 GHz Giant Metrewave Radio Telescope (GMRT) observations and existing observations at higher frequencies, we conclude the partial shell structure showing synchrotron emission is embedded in an extended HII region of size ∼ 4'. We find the spectrum of the diuse HII region to turn over between 1.4 GHz and 330 MHz. HI absorption spectrum puts a lower limit of 5 kpc on its distance from Sun. Based on morphology, non-thermal polarized emission and size, this object is found to be one of the youngest supernova remnants discovered in the Galaxy with an estimated age of ∼ 100 - 500 years.
Keywords : supernova remnants – radio lines: ISM – H II regions – radio continuum