Unexpected gamma-ray signal in the vicinity of 1ES 0229+200

TL;DR

This paper reports the discovery of an unexpected, unresolved gamma-ray signal near 1ES 0229+200 in Fermi-LAT data, characterized by a steep spectrum and point-like appearance, with no clear association to known sources.

Contribution

The study identifies a new gamma-ray excess close to a known blazar, highlighting a potentially new gamma-ray emitter with unique spectral and spatial features.

Findings

Detected an unexpected gamma-ray excess within 3° of 1ES 0229+200

The excess shows a steep energy spectrum and appears point-like

No known sources or multiwavelength counterparts linked to the signal

Abstract

We report on an unidentified gamma-ray signal found in the region around the BL Lac object 1ES 0229+200. It was recognized serendipitously in our analysis of 6.2 years of Fermi-LAT data at a distance less than 3{\deg} away from the blazar. The observed excess of counts manifests itself as an unexpected local maximum in the test statistic map. Although several Fermi-LAT sources have been identified in this area we were not able to link them to the position of this residual signal. A clear association with sources visible in other wavebands was not successful either. We briefly discuss characteristics of this unresolved phenomenon. Our results suggest a steep energy spectrum and a point-like nature of this candidate gamma-ray emitter.