Saved in:
Bibliographic Details
Main Authors: Jiang, Xiong, Lei, Hai, Huang, Hao-Yi, Zhang, Wei, Li, Yang-Ji, Wei, Da-Ming
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2603.21110
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914413527695360
author Jiang, Xiong
Lei, Hai
Huang, Hao-Yi
Zhang, Wei
Li, Yang-Ji
Wei, Da-Ming
author_facet Jiang, Xiong
Lei, Hai
Huang, Hao-Yi
Zhang, Wei
Li, Yang-Ji
Wei, Da-Ming
contents We report the first detection of GeV gamma-ray flaring activity from the compact symmetric object (CSO)-like source 4C 76.03, based on 17 years of Fermi-LAT observations. Its long-term, time-averaged gamma-ray properties are consistent with the 4FGL-DR4 catalog. However, a time-resolved analysis with 100-day binning reveals two prominent flares occurring on timescales of approximately 30 days and 20 days, separated by about 2.5 years, with nearly identical fluxes, test statistic (TS) values, and photon indices. The short-timescale variability indicates localized and transient energy dissipation in the nuclear region, likely associated with newly injected jet components. Although the gamma-ray emission does not directly trace the long-term jet power responsible for building the observed radio structure, it demonstrates that the central engine remains active. In the context of CSO evolution, 4C 76.03 may represent a rare transitional case, where repeated energy injections allow the source to exceed the canonical 500 pc scale of most CSOs, providing key insight into the early stages of radio jet evolution.
format Preprint
id arxiv_https___arxiv_org_abs_2603_21110
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The First GeV Gamma-Ray Flares from the CSO-like Source 4C 76.03
Jiang, Xiong
Lei, Hai
Huang, Hao-Yi
Zhang, Wei
Li, Yang-Ji
Wei, Da-Ming
High Energy Astrophysical Phenomena
We report the first detection of GeV gamma-ray flaring activity from the compact symmetric object (CSO)-like source 4C 76.03, based on 17 years of Fermi-LAT observations. Its long-term, time-averaged gamma-ray properties are consistent with the 4FGL-DR4 catalog. However, a time-resolved analysis with 100-day binning reveals two prominent flares occurring on timescales of approximately 30 days and 20 days, separated by about 2.5 years, with nearly identical fluxes, test statistic (TS) values, and photon indices. The short-timescale variability indicates localized and transient energy dissipation in the nuclear region, likely associated with newly injected jet components. Although the gamma-ray emission does not directly trace the long-term jet power responsible for building the observed radio structure, it demonstrates that the central engine remains active. In the context of CSO evolution, 4C 76.03 may represent a rare transitional case, where repeated energy injections allow the source to exceed the canonical 500 pc scale of most CSOs, providing key insight into the early stages of radio jet evolution.
title The First GeV Gamma-Ray Flares from the CSO-like Source 4C 76.03
topic High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2603.21110