2018/10/24 by Ning Jiang, Tinggui Wang, Hongyan Zhou +7 · 2 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Black hole (networking) #Galactic Center #Galaxies: Formation, Evolution, Phenomena #Galaxy #Intermediate-mass black hole #Luminosity #Star cluster #Stellar black hole #Supermassive black hole #astro-ph.GA
paper · pdf · doi:10.3847/1538-4357/aaeb90
ApJ accepted, 2 tables, 6 figures
arxiv created 2018/10/24 · openalex created_date 2018/10/26 · openalex publication_date 2018/12/10 · arxiv updated 2018/12/19 · openalex updated_date 2026/08/05
Abstract We report the discovery of an active intermediate-mass black hole (IMBH) candidate in the center of nearby barred bulgeless galaxy NGC 3319. The point X-ray source revealed by archival Chandra and XMM-Newton observations is spatially coincident with the optical and UV galactic nuclei from Hubble Space Telescope observations. The spectral energy distribution derived from the unresolved X-ray and UV-optical flux is comparable with active galactic nuclei rather than ultraluminous X-ray sources, although its bolometric luminosity is only . Assuming an Eddington ratio range between 0.001 and 1, the black hole mass ( ) will be in the range 3 × 10 2 −3 × 10 5 , placing it in the so-called IMBH regime and making it possibly one of the lowest reported so far. Estimates from other approaches (e.g., fundamental plane, X-ray variability) also suggest ≲ 10 5 . Similar to other BHs in bulgeless galaxies, the discovered IMBH resides in a nuclear star cluster with mass of ∼6 × 10 6 . The detection of such a low-mass BH offers us an ideal chance to study the formation and early growth of SMBH seeds, which may result from the bar-driven inflow in late-type galaxies with a prominent bar such as NGC 3319.