Are x-ray detected active galactic nuclei in dwarf galaxies gamma-ray bright?

Crnogorčević M, Linden T, Peter AH (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Physical Review D American Physical Society

Book Volume: 113

Article Number: 123059

Journal Issue: 12

DOI: 10.1103/7DKC-T7F2

Abstract

The γ-ray emission from active galactic nuclei (AGN), including both beamed blazars and misaligned AGN, dominates the extragalactic γ-ray point-source population count and flux. While multiwavelength studies have detected an increasing number of AGN within dwarf galaxies in the local Universe, γ-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 regime, offering insight into the early evolution of SMBHs. Using 15 years of Fermi-LAT data, we present the first search for γ-ray emission from dwarf-galaxy AGN. In the sample of 67 x-ray-selected dwarf-galaxy AGN, we find no sources that exceed the Fermi-LAT detection threshold. However, a joint likelihood analysis reveals a modest, trials-corrected population-level excess (∼2σ) above blank-field expectations at very soft photon indices Γ ≳ 3.8 above 500 MeV. This hint is most pronounced when source contributions are weighed by Mα IMBH,i=d2 i, with α ≃ 1–1.5, suggesting—but not confirming—that γ-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.

Involved external institutions

The Oskar Klein Centre SE Sweden (SE) Ohio State University US United States (USA) (US)

How to cite

APA:

Crnogorčević, M., Linden, T., & Peter, A.H. (2026). Are x-ray detected active galactic nuclei in dwarf galaxies gamma-ray bright? Physical Review D, 113(12). https://doi.org/10.1103/7DKC-T7F2

MLA:

Crnogorčević, Milena, Tim Linden, and Annika H.G. Peter. "Are x-ray detected active galactic nuclei in dwarf galaxies gamma-ray bright?" Physical Review D 113.12 (2026).

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