Search for Gamma-ray emission from Abell 119 galaxy cluster using INTEGRAL/ISGRI, COMPTEL, and DAMPE data

Abstract

We present a comprehensive search for non-thermal high-energy $γ$-ray emission from the nearby merging galaxy cluster Abell~119 ($z=0.044$) using archival observations spanning over seven decades in photon energy. Our analysis combines hard X-ray data from INTEGRAL/ISGRI (30--100~keV), MeV $γ$-ray observations from COMPTEL (0.75--30~MeV), and GeV--TeV data from the DArk Matter Particle Explorer (DAMPE; 3~GeV--1~TeV). No statistically significant emission is detected at the cluster position in any energy band. In the hard X-ray regime, we derive a $3σ$ upper limit of $F_{30-100\,\mathrm{keV}} \lesssim 8.5 \times 10^{-11}$~erg~cm$^{-2}$~s$^{-1}$ from ISGRI mosaic imaging. Reanalysis of archival COMPTEL data yields 95\% confidence-level upper limits ranging from $\sim 9 \times 10^{-11}$ to $\sim 8 \times 10^{-10}$~erg~cm$^{-2}$~s$^{-1}$ across 0.75--30~MeV. In the GeV--TeV range, DAMPE constrains the differential energy flux to $\sim 10^{-12}$--$10^{-10}$~erg~cm$^{-2}$~s$^{-1}$ (95\% confidence level). These results provide independent multi-band constraints on the reported GeV excess from recent Fermi-LAT studies. While our DAMPE limits do not exclude the flux levels claimed in those analyses, the absence of confirmation across keV--MeV--GeV bands indicate that any non-thermal emission from Abell~119 remains tentative.

Figures (4)

• Figure 1: INTEGRAL/ISGRI mosaic significance maps of the Abell 119 field in four logarithmically spaced energy bands: Band 1 (30--41 keV; top left), Band 2 (41--54.5 keV; top right), Band 3 (54.5--73.5 keV; bottom left), and Band 4 (73.5--99.5 keV; bottom right). The white cross marks the cluster center at RA = $14.035^{\circ}$, Dec = $-1.200^{\circ}$ (J2000). Green circles indicate sources detected at $>5\sigma$ significance in the ISGRI mosaic images. The color scale ranges from $0\sigma$ (blue) to $+6\sigma$ (red). No significant emission is detected at the position of Abell 119 in any energy band.
• Figure 2: SED plot of Abell 119 in the MeV band from COMPTEL observations. The data points represent 95% confidence-level upper limits on $E^{2}dN/dE$ derived from bin-by-bin maximum-likelihood analysis in four logarithmically spaced energy bins covering 0.75--30 MeV. No statistically significant $\gamma$-ray emission is detected.
• Figure 3: SED plot of Abell 119 from DAMPE observations. The data points represent 95% confidence-level upper limits on $E^{2}dN/dE$ derived from bin-by-bin likelihood analysis in ten logarithmically spaced energy bins between 3 GeV and 1 TeV. No significant $\gamma$-ray excess is detected in any energy bin.
• Figure 4: SED plot of Abell 119 from hard X-rays to GeV energies. Downward arrows with horizontal energy bars denote upper limits from Swift/BAT, INTEGRAL/ISGRI, COMPTEL, and DAMPE. The Fermi-LAT point shows the band-integrated energy flux for the maximum-TS spatial model of Harale2025.