Detection of Gamma-Rays from the Protostellar Jet in the HH 80-81 System

Abstract

Considering that the existence of relativistic particles in the protostellar jet has been confirmed by the detection of linearly polarized radio emission from the HH 80-81 jet, we search for gamma-rays from the HH 80-81 system using ten-year {\it Fermi}-LAT observations. A significant point-like $\gamma$-ray excess is found in the direction of the HH 80-81 system with Test-Statistic (TS) value $>$100, which is likely produced in the HH 80-81 jet. The $\gamma$-ray spectrum extends only to 1 GeV with a photon index of 3.5. No significant variability is found in the gamma-ray emission. It is discussed that the properties of HH 80-81 jet suffice for producing the observed $\gamma$-rays.