399 research outputs found
An accretion-jet model for M87: interpreting the spectral energy distribution and Faraday rotation measure
M87 is arguably the best supermassive black hole (BH) to explore the jet
and/or accretion physics due to its proximity and fruitful high-resolution
multi-waveband observations. We model the multi-wavelength spectral energy
distribution (SED) of M87 core that observed at a scale of 0.4 arcsec (, is gravitational radius) as recently presented by
Prieto et al. Similar to Sgr A*, we find that the millimeter bump as observed
by Atacama Large Millimeter/submillimeter Array (ALMA) can be modeled by the
synchrotron emission of the thermal electrons in advection dominated accretion
flow (ADAF), while the low-frequency radio emission and X-ray emission may
dominantly come from the jet. The millimeter radiation from ADAF dominantly
come from the region within , which is roughly consistent with the
recent very long baseline interferometry observations at 230\,GHz. We further
calculate the Faraday rotation measure (RM) from both ADAF and jet models, and
find that the RM predicted from the ADAF is roughly consistent with the
measured value while the RM predicted from the jet is much higher if jet
velocity close to the BH is low or moderate (e.g., ). With the constraints from the SED modeling and RM, we
find that the accretion rate close to the BH horizon is ( is Bondi accretion rate), where the
electron density profile, , in the accretion flow
is consistent with that determined from X-ray observation inside the Bondi
radius and recent numerical simulations.Comment: 8 pages, 3 figures, accepted for publication in Ap
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