GeV emission in the region of the supernova remnant G51.26+0.09

Miguel Araya

Published 2021-02-17Version 1

Using data from the \emph{Fermi} Large Area Telescope we perform a detailed study of the GeV emission in the direction of G51.26+0.09 to constrain its origin, its possible relation to this SNR, the star-forming region G051.010+00.060 seen nearby in the sky, or the pulsars known in the region, and to derive the properties of the underlying cosmic ray particles producing the non-thermal radiation. We also study properties of the environment which could shed light on the nature of the source of the gamma rays. We compare the morphology of the gamma-ray radiation to that of the emission detected at radio wavelengths in previous observations. Modeling the measured spectrum and fluxes of the high-energy radiation allows us to derive the properties of the particle populations that could produce this emission in several possible scenarios. We use existing data from $^{13}$CO emission and neutral hydrogen emission to probe the environment, searching for possible morphological features associated to the gamma rays and SNR. We rule out the star-forming region G051.010+00.060 as the origin of the GeV emission. The correspondence seen between the gamma-ray and radio morphologies support an SNR scenario, where the object responsible is more extended than G51.26+0.09, or is made up of more than one unresolved SNR. Given the flat spectral energy distribution observed at GeV energies and the radio flux upper limits, we also rule out bremsstrahlung emission as the origin of the gamma rays. A pulsar wind nebula origin of the high-energy photons, associated to the pulsar PSR J1926+1613, cannot be ruled out or confirmed, due to its unknown parameters such as spin-down power and age, while the pulsars PSR J1924+1628 and PSR J1924+1631 are too far away to be the source of gamma rays.