Radio Observations of Supernova Remnant G1.9+0.3

Understand

We present 1 to 10GHz radio continuum flux density, spectral index, polarisation and Rotation Measure (RM) images of the youngest known Galactic Supernova Remnant (SNR) G1.9+0.3, using observations from the Australia Telescope Compact Array (ATCA).

• We have conducted an expansion study spanning 8 epochs between 1984 and 2017, yielding results consistent with previous expansion studies of G1.9+0.3.
• We find a mean radio continuum expansion rate of ($0.78 \pm 0.09$) per cent year$^{-1}$ (or $\sim8900$ km s$^{-1}$ at an assumed distance of 8.5 kpc), although the expansion rate varies across the SNR perimeter.
• In the case of the most recent epoch between 2016 and 2017, we observe faster-than-expected expansion of the northern region.