Stellar objects as gamma-ray sources

P.. BENAGLIA

Johannesburg

Simposio; Ninth International Fermi Symposium; 2021

Goddard Space Flight Center/U. of Johannesburg

A good fraction of high-energy (HE) sources do not have confirmed counterparts at any of the other branches of the electromagnetic spectrum. In the extragalactic sky, most of those sources with counterparts are blazars, the AGN subclass. HE sources with identified counterparts in our Galaxy do have a wide range of categories, as supernovae remnants, pulsar wind nebulae, microquasars, etc. Additional scenarios, involving stars in alternate -or earlier- stages, have been modelled, although evidence of correlation has been rather elusive from the observational point of view. I will present the results of unidentified HE source counterpart searches in the stellar objects universe, especially related to hot, massive stars with strong stellar winds, and pulsars. This long-standing investigation focus on the central region of the Cygnus constellation, crowded with stars, and it is based on radio observations of arcsec scale at low frequencies, where the non-thermal emission is expected to be paramount.