Are X-Ray Detected Active Galactic Nuclei in Dwarf Galaxies Gamma-Ray Bright?

The $\gamma$-ray emission from active galactic nuclei (AGN), including both beamed blazars and misaligned-AGN, dominates the extragalactic $\gamma$-ray point-source population count and flux. While multi-wavelength studies have detected an increasing number of AGN within dwarf galaxies in the local Universe, $\gamma$-ray emission has so far only been associated with systems hosting supermassive black holes (SMBHs). Dwarf-galaxy AGN are of particular interest because their central black holes fall in the intermediate-mass black hole (IMBH) regime, offering insight into the early evolution of SMBHs. Using 15~years of $\mathit{\text{Fermi}}$-LAT data, we present the first search for $\gamma$-ray emission from dwarf-galaxy AGN. In the sample of 74 X-ray-selected dwarf-galaxy AGN, we find no sources that exceed the $\mathit{\text{Fermi}}$-LAT detection threshold. However, a joint-likelihood analysis reveals a modest, trials-corrected population-level excess ($\sim 2\sigma$) above blank-field expectations at very soft photon indices $\mathrm{\Gamma }\gtrsim 3.8$ above 500~MeV. This hint is most pronounced when source contributions are weighed by $M_{\mathrm{I}\mathrm{M}\mathrm{B}\mathrm{H},i}^{\alpha }\mathrm{/}{d}_i^2$, with $\alpha \simeq 1$–$1.5$, suggesting – but not confirming – that $\gamma$-ray emission could scale with the central black hole mass or a property correlated with it (e.g., accretion rate), but with a markedly softer spectrum than in SMBH-hosted AGN.