Search for dark matter annihilation to γ-rays from nearby galaxy clusters with <i>Fermi</i>-LAT data

ABSTRACT In this work, we adopt 16 yr of Fermi-LAT data to search for $\gamma$-ray signal from dark matter annihilation in 16 nearby galaxy clusters. The NFW profile is applied to model the dark matter distribution. No significant ($&amp;gt; 5\sigma$) $\gamma$-ray signal is found in the scenarios of dark matter annihilations. However, the peak test statistic (TS) values are larger than 16.0 for Coma and Perseus clusters. Further analyses strongly indicate that the $\gamma$-ray emission of the Coma region is irrelevant to the dark matter annihilations. For Perseus cluster, the best-fitting TS value is $\sim$ 20.0 for $\chi \chi \rightarrow \tau ^{+}\tau ^{-}$ at $m_{\chi } \sim$ 38 GeV, but the corresponding $\left&amp;lt;\sigma {v}\right&amp;gt;$ is in conflict with the constraint from dwarf spheroidal galaxies. Meanwhile, the peak TS value of the possible excess from Perseus is not increasing with time continually. The true origin of the potential signal is still unclear.