Detection of the extended $\gamma$-ray emission around supernova remnant DA 530 with Fermi-LAT

TL;DR

This study detects extended GeV gamma-ray emission around supernova remnant DA 530 using Fermi-LAT data, indicating hadronic processes and proton acceleration in the remnant's shock.

Contribution

First detection of extended gamma-ray emission around DA 530, linking it to hadronic processes and cosmic-ray acceleration in the remnant.

Findings

Gamma-ray spectrum follows a power law with index 2.23.

Gamma-ray emission is more extended than the radio shell.

Emission likely originates from hadronic interactions with molecular clouds.

Abstract

We report the extended GeV $\gamma$-ray emission around the high Galactic latitude supernova remnant (SNR) DA 530 with the PASS 8 data recorded by the Fermi Large Area Telescope (Fermi-LAT). The $\gamma$-ray spectrum in the energy range of 100 MeV - 1 TeV follows a power law model with an index of 2.23. The much more extended $\gamma$-ray emission than the radio shell of DA 530 and the spatial coincidence with the molecular cloud suggest that the $\gamma$-ray emission could be originated from the hadronic process, where the high energy protons are accelerated in and escaped from the shock of DA 530. With a steady-state injection model of protons, the $\gamma$-ray spectrum can be well fitted with the typical Galactic value for diffusion coefficient and the low energy content of the total escaped protons.