Constraints on the mass accretion rate onto the supermassive black hole of cygnus a using the submillimeter array

Wen Ping Lo, Keiichi Asada, Satoki Matsushita, Masanori Nakamura, Hung Yi Pu, Chihyin Tseng, Kazunori Akiyama, Juan Carlos Algaba, Geoffrey C. Bower, Ramprasad Rao, Jun Yi Koay, Patrick M. Koch, Shoko Koyama, Paul T.P. Ho, Makoto Inoue, Kazunori Akiyama

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


We present the first detailed polarimetric studies of Cygnus A at 230 GHz with the Submillimeter Array (SMA) to constrain the mass accretion rate onto its supermassive black hole. We detected the polarized emission associated with the core at a fractional polarization of 0.73 ± 0.15%. This low fractional polarization suggests that the polarized emission is highly depolarized. One of the possible explanations is due to a significant variance in the Faraday rotation measure within the synthesized beam. By assuming the Faraday depolarization caused by inhomogeneous column density of the magnetized plasma associated with the surrounding radiatively-inefficient accretion flow within the SMA beam, we derived the constraint on the mass accretion rate to be larger than 0.15 M yr-1 at the Bondi radius. The derived constraint indicates that an adiabatic inflow-outflow solution or an advection-dominated accretion flow should be preferable as the accretion flow model in order to explain the jet power of Cygnus A.

Original languageEnglish
Article number35
JournalAstrophysical Journal
Issue number1
Publication statusPublished - 2021 Apr 16

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Constraints on the mass accretion rate onto the supermassive black hole of cygnus a using the submillimeter array'. Together they form a unique fingerprint.

Cite this