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Galaxy clusters could produce gamma-rays from inverse Compton scattering ofcosmic ray electrons or hadronic interactions of cosmic ray protons with theintracluster medium. It is still an open question on whether gamma-ray emission($>$ GeV energies) has been detected from galaxy clusters. We carry out asystematic search for gamma-ray mission based on 300 galaxy clusters selectedfrom the 2500 deg.$^2$ SPT-SZ survey after sorting them in descending order of$M_{500}/z^2$, using about 15 years of Fermi-LAT data in the energy rangebetween 1-300 GeV. We were able to detect gamma-ray emission with significanceof about $6.1\sigma$ from one cluster, viz SPT-CL J2012-5649. The estimatedphoton energy flux from this cluster is approximately equal to $1.3 \times10^{-6}$ MeV cm$^{-2}$ s$^{-1}$. The gamma-ray signal is observed between$1-10$ GeV with the best-fit spectral index equal to $-3.61 \pm 0.33$. However,since there are six radio galaxies spatially coincident with SPT-CL J2012-5649within the Fermi-LAT PSF, we cannot rule out the possibility this signal couldbe caused by some of these radio galaxies. Six other SPT-SZ clusters showevidence for gamma-ray emission with significance between $3-5\sigma$. None ofthe remaining clusters show statistically significant evidence for gamma-rayemission.

Search for GeV Gamma-Ray Emission from SPT-SZ selected Galaxy Clusters with 15 years of Fermi-LAT data