2007/08/02 by Nick Devereux, Andrew Shearer
Physics and Astronomy · #Active galactic nucleus #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #Ionization #Kinematics #Line (geometry) #Luminosity #RADIUS #astro-ph
paper · pdf · doi:10.1086/522292
Accepted for Publication in ApJ 7/21/07
arxiv created 2007/08/02 · openalex publication_date 2007/12/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A new model is presented that explains the origin of the broad emission lines observed in the LINER/Seyfert nucleus of M81 in terms of a steady state spherically symmetric inflow, amounting to ~1 × 10 -5 M ☉ yr -1 , which is sufficient to explain the luminosity of the active galactic nucleus (AGN). The emitting volume has an outer radius of ~1 pc, making it the largest broad-line region (BLR) yet to be measured, and it contains a total mass of ~5 × 10 -2 M ☉ of dense, ~10 8 cm -3 , ionized gas, leading to a very low filling factor of ~5 × 10 -9 . The fact that the BLR in M81 is so large may explain why the AGN is unable to sustain the ionization seen there. Thus, the AGN in M81 is not simply a scaled-down quasar.