A jet-dominated model for a broad-band spectral energy distribution of the nearby low-luminosity active galactic nucleus in M94

作者：van Oers Pieter; Markoff Sera; Uttley Phil; McHardy Ian; van der Laan Tessel; Meyer Jennifer Donovan; Connors Riley

来源：Monthly Notices of the Royal Astronomical Society, 2017, 468(1): 435-450.

DOI：10.1093/mnras/stx514

• accretion
• accretion discs
• black hole physics
• radiation mechanisms: non-thermal
• galaxies: active
• galaxies: jets
• radio continuum: galaxies

We have compiled a new multiwavelength spectral energy distribution (SED) for the closest obscured low-ionization emission-line region active galactic nucleus (AGN), NGC 4736, also known as M94. The SED comprises mainly high-resolution (mostly sub-arcsecond, or, at the distance to M94, less than or similar to 23 pc from the nucleus) observations from the literature, archival data, as well as previously unpublished sub-millimetre data from the Plateau de Bure Interferometer (PdBI) and the Combined Array for Research in Millimeter-wave Astronomy, in conjunction with new electronic MultiElement Radio Interferometric Network (e-MERLIN) L-band (1.5 GHz) observations. Thanks to the e-MERLIN resolution and sensitivity, we resolve for the first time a double structure composed of two radio sources separated by similar to 1 arcsec, previously observed only at higher frequency. We explore this data set, which further includes non-simultaneous data from the Very Large Array, the Gemini telescope, the Hubble Space Telescope and the Chandra X-ray observatory, in terms of an outflow-dominated model. We compare our results with previous trends found for other AGN using the same model (NGC 4051, M81*, M87 and Sgr A*), as well as hard-and quiescent-state X-ray binaries. We find that the nuclear broad-band spectrum of M94 is consistent with a relativistic outflow of low inclination. The findings in this work add to the growing body of evidence that the physics of weakly accreting black holes scales with mass in a rather straightforward fashion.

• 出版日期2017-6