2024/09/16 by S. J. Kimbrell, Kimbrell, Seth, Amy E. Reines +1
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences
paper · pdf · doi:10.48550/arxiv.2409.10630
openalex publication_date 2024/09/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present the discovery of a luminous X-ray AGN in the dwarf galaxy merger RGG 66. The black hole is predicted to have a mass of M\rm BH ∼ 105.4 M_\odot and to be radiating close to its Eddington limit (L\rm bol/L\rm Edd ∼ 0.75). The AGN in RGG 66 is notable both for its presence in a late-stage dwarf-dwarf merger and for its luminosity of L\rm 2-10~keV = 1042.2 erg s-1, which is among the most powerful AGNs known in nearby dwarf galaxies. The X-ray spectrum has a best-fit photon index of Γ= 2.4 and an intrinsic absorption of NH ∼ 1021 cm-2. These results come from a follow-up \it Chandra X-ray Observatory study of four irregular/disturbed dwarf galaxies with evidence for hosting AGNs based on optical spectroscopy. The remaining three dwarf galaxies do not have detectable X-ray sources with upper limits of L\rm 2-10~ keV \lesssim 1040 erg s-1. Taken at face value, our results on RGG 66 suggest that mergers may trigger the most luminous of AGNs in the dwarf galaxy regime, just as they are suspected to do in more massive galaxy mergers.