1996/04/04 by Heino Falcke, H. Falcke · 67 citations
Physics and Astronomy · #Acceleration #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Centaurus A #Classical mechanics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Jet (fluid) #Luminosity #Mechanics #Physics #Radio galaxy #Spiral galaxy #X-shaped radio galaxy #astro-ph
paper · pdf · doi:10.1086/310085
published in The Astrophysical Journal 464(1), L67-L70 (IOP Publishing) · ApJ Letters, accepted for publication, AAS LaTex, 8 pages, 1 PS-figure, also available at http://www.astro.umd.edu/~hfalcke/publications.html or by request
arxiv created 1996/04/04 · openalex publication_date 1996/06/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In this Letter we apply the jet-disk symbiosis model developed for Sagittarius A* to M81*—the nucleus of the nearby galaxy M81. The model accurately predicts the radio flux and size of M81* for the observed bolometric luminosity of the nuclear source, with no major free parameter except for the inclination angle. We point out that the usually applied, free conical jet emission model implies a longitudinal pressure gradient that must lead to a moderate acceleration of the jet along its flow direction. This usually neglected, gradual acceleration naturally accounts for the inverted spectrum and the size-frequency relation of M81*, and may be a general feature of radio cores. So far, M81* is the best case for a radio-loud jet nature of the compact radio core in the nucleus of a spiral galaxy. The fact that one can account for Sgr A* and M81* with the same model by simply changing the accretion rate strongly supports the jet-disk symbiosis model as an explanation for the compact radio cores of galaxies in general.