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The supernova remnant (SNR) G288.8–6.3 was recently discovered with
ASKAP as a faint radio shell at a high Galactic latitude.
Burger-Scheidlin et al. have made the first detailed investigation of the
gamma-ray emission from the G288.8–6.3 region, aiming to characterise
the high-energy emission in the GeV regime from the newly discovered
SNR, which has been dubbed Ancora (for reasons to be explained in tomorrow's ADAP).
Fifteen years of Fermi-Large Area Telescope (LAT) data were analysed
at energies between 400 MeV and 1 TeV with the detection of spatially
extended gamma-ray emission coinciding with the radio SNR.
The gamma-ray excess was modelled using different spatial and spectral models,
with a radial disk spatial model in combination with a power-law spectral model
found to be the preferred model. Morphologically, hotspots seen above 1 GeV are well-correlated
with the bright western part of the radio shell.
The figure above shows the significance map of the G288.8–6.3 region
as seen with Fermi-LAT after fitting with a RadialDisk spatial model and
a PowerLaw spectral model, including modelling of the
Fermi source 4FGL J1028.7-6431c,
overlaid with Fermi contours for significance above 1 GeV, and the smoothed radio
contours from the ASKAP instrument at 954 MHz.
It is not clear whether 4FGL J1028.7-6431c is
actually associated with Ancora, or is an unrelated source overlapping with the SNR.
Ancora is the eighth SNR detected at high Galactic latitude with
Fermi-LAT. This new population of remnants has the potential to
constrain the physics of particle diffusion and escape from SNRs into
the Galaxy.
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