Radio Observations of Supernova Remnant G1.9+0.3

Abstract

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 $\sim 8900$ 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. We find a global spectral index for G1.9+0.3 of $-0.81\pm 0.02$ (76 MHz$-$10 GHz). Towards the northern region, however, the radio spectrum is observed to steepen significantly ($\sim -$1). Towards the two so called (east & west) "ears" of G1.9+0.3, we find very different RM values of 400-600 rad m${}^2$ and 100-200 rad m${}^2$ respectively. The fractional polarisation of the radio continuum emission reaches (19 $\pm$ 2)~per~cent, consistent with other, slightly older, SNRs such as Cas~A.

17 Pages, 13 Figures

References in corpus (16)

• The ATNF Pulsar Catalogue
• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• Primary particle acceleration above 100 TeV in the shell-type Supernova Remnant RX J1713.7-3946 with deep H.E.S.S. observations
• The Youngest Galactic Supernova Remnant: G1.9+0.3
• Pulsar Rotation Measures and Large-scale Magnetic Field Reversals in the Galactic Disk
• Variation of cosmic ray injection across supernova shocks
• The radio expansion and brightening of the very young supernova remnant G1.9+0.3
• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey II: Galactic Plane $345^{\circ }<l<67^{\circ }$, $180^{\circ }<l<240^{\circ }$
• Clustering of Local Group distances: publication bias or correlated measurements? IV. The Galactic Center
• The Mopra Southern Galactic Plane CO Survey - Data Release 3
• On the radio spectra of supernova remnants
• X-ray Spectral Variations in the Youngest Galactic Supernova Remnant G1.9+0.3
• Asymmetric Expansion of the Youngest Galactic Supernova Remnant G1.9+0.3
• A compiled catalog of rotation measures of radio point sources
• A 20 Year Radio Light Curve for the Young Supernova Remnant G1.9+0.3

Cited by in corpus (11)

• The Science of the Einstein Telescope
• Mysterious Odd Radio Circle near the Large Magellanic Cloud -- An Intergalactic Supernova Remnant?
• New ASKAP Radio Supernova Remnants and Candidates in the Large Magellanic Cloud
• Witnessing History: Rates and Detectability of Naked-Eye Milky-Way Supernovae
• ATCA Study of Small Magellanic Cloud Supernova Remnant 1E 0102.2-7219
• Magneto hydrodynamic simulations of the supernova remnant G1.9+0.3
• On the Potential of Faraday Tomography to Identify Shock Structures in Supernova Remnants
• SN 1885A and supernova remnants in the centre of M31 with LOFAR
• Brightening and Fading in the Youngest Galactic Supernova Remnant G1.9+0.3: 13 years of monitoring with the Chandra X-ray Observatory
• X-ray Measurements of ${}^{44}$Ti in Four Supernova Remnants
• On the Determination of the Evolutionary Status of Supernova Remnants from Radio Observation Data