Radio-continuum emission from the young galactic supernova remnant G1.9+0.3

• Main Authors: de Horta A.Y., Filipović M.D., Crawford E.J., Stootman F.H., Pannuti T.G., Bozzetto L.M., Collier J.D., Sommer E.R., Kosakowski A.R.
• Format: Article
• Language: English
• Published: Astronomical Observatory, Department of Astronomy, Belgrade 2014-01-01
• Series: Serbian Astronomical Journal
• Subjects: ISM: individual objects: G1.9+0.3; ISM: supernova remnants; radiocontinuum: ISM; supernovae: general
• Online Access: http://www.doiserbia.nb.rs/img/doi/1450-698X/2014/1450-698X1400001H.pdf
• ISSN: 1450-698X; 1820-9289

We present an analysis of a new Australia Telescope Compact Array (ATCA) radio-continuum observation of supernova remnant (SNR) G1.9+0.3, which at an age of ~181±25 years is the youngest known in the Galaxy. We analysed all available radio-continuum observations at 6-cm from the ATCA and Very Large Array. Using this data we estimate an expansion rate for G1.9+0.3 of 0.563%±0.078% per year between 1984 and 2009. We note that in the 1980's G1.9+0.3 expanded somewhat slower (0.484% per year) than more recently (0.641% per year). We estimate that the average spectral index between 20-cm and 6-cm, across the entire SNR is α={0.72±0.26 which is typical for younger SNRs. At 6-cm, we detect an average of 6% fractionally polarised radio emission with a peak of 17%§3%. The polarised emission follows the contours of the strongest of X-ray emission. Using the new equipartition formula we estimate a magnetic field strength of B≈273μG, which to date, is one of the highest magnetic field strength found for any SNR and consistent with G1.9+0.3 being a very young remnant.