# Discovery of TeV $\gamma$-ray emission from the neighbourhood of the supernova remnant G24.7+0.6 by MAGIC

## TL;DR

This paper reports the discovery of very high energy gamma-ray emission near supernova remnant G24.7+0.6 using MAGIC, with a broad spectrum extending from 60 MeV to 5 TeV, likely due to proton interactions in the surrounding medium.

## Contribution

First detection of TeV gamma-ray emission from near SNR G24.7+0.6, linking it with Fermi-LAT data and proposing a hadronic origin of the emission.

## Key findings

- Detection of a new gamma-ray source  near SNR G24.7+0.6
- Broadband spectrum from 60 MeV to 5 TeV fits a power-law with cutoff
- Emission likely caused by proton-proton interactions in dense medium

## Abstract

SNR G24.7+0.6 is a 9.5 kyrs radio and $\gamma$-ray supernova remnant evolving in a dense medium. In the GeV regime, SNR G24.7+0.6 (3FHL\,J1834.1--0706e/FGES\,J1834.1--0706) shows a hard spectral index ($\Gamma$$\sim$2) up to $200$\,GeV, which makes it a good candidate to be observed with Cherenkov telescopes such as MAGIC. We observed the field of view of \snr\ with the MAGIC telescopes for a total of 31 hours. We detect very high energy $\gamma$-ray emission from an extended source located 0.34\degr\ away from the center of the radio SNR. The new source, named \mgc\ is detected up to 5\,TeV, and its spectrum is well-represented by a power-law function with spectral index of $2.74 \pm 0.08$. The complexity of the region makes the identification of the origin of the very-high energy emission difficult, however the spectral agreement with the LAT source and overlapping position at less than 1.5$\sigma$ point to a common origin. We analysed 8 years of \fermi-LAT data to extend the spectrum of the source down to 60\,MeV. \fermi-LAT and MAGIC spectra overlap within errors and the global broad band spectrum is described by a power-law with exponential cutoff at $1.9\pm0.5$\,TeV. The detected $\gamma$-ray emission can be interpreted as the results of proton-proton interaction between the supernova and the CO-rich surrounding.