Cosmic Rays origin studies in the W 44 region with Fermi-LAT and MAGIC observations
W 44 is a well-known Supernova Remnant (SNR) observed in high-energy gamma-rays, widely studied to investigate cosmic ray (CR) acceleration. Several analyses of the W 44 surroundings showed the presence of a gamma-ray emission offset from the radio SNR shell. This emission is thought to originate from escaped high-energy CRs. We present a detailed analysis of the W 44 region as seen by Fermi-LAT, focusing on the spatial and spectral characteristics of both W 44 SNR and its surroundings. The spatial analysis was limited to energies above 1 GeV in order to exploit the improved angular resolution of the instrument, deriving a detailed description of the region morphology. The spectral analysis was extended down to 100 MeV, favouring the hadronic origin of gamma-rays. Observations of the northwestern region of W 44, also known as SRC-1 from previous works, were conducted with the MAGIC telescopes in the very-high-energy gamma-ray band. We analysed MAGIC data above 130 GeV exploiting the spatial information derived from the Fermi-LAT analysis above 1 GeV. Here we show the results of both analyses and the combined Fermi-LAT and MAGIC spectra. An interpretation model was developed, assuming that the gamma-ray emission from the surroundings is due to clouds located near W 44 and illuminated by CRs escaping along the SNR’s magnetic field lines, thus obtaining constraining information on the diffusion coefficient of the escaped CRs.
Authors
- F. Giordano (ORCID: https://orcid.org/0000-0002-8651-2394)
- Riccardo Di Tria
- Giovanni Morlino (ORCID: https://orcid.org/0000-0002-5014-4817)
- A. Hahn (ORCID: https://orcid.org/0000-0003-0827-5642)
- L. Di Venere (ORCID: https://orcid.org/0000-0003-0703-824X)
- David Green (ORCID: https://orcid.org/0000-0002-9488-6601)
- Marcel C. Strzys
- Francesca Romana Pantaleo
Publication Details
- Published
- 2024-11-26
- DOI
- https://doi.org/10.22323/1.417.0044
- Primary Topic
- Astrophysics and Cosmic Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00