MHD Models and Synthetic Synchrotron Maps for the Jet of M87

Abstract

We present a self-consistent MHD model for the jet of M87. The model consist of two distinct zones: an inner relativistic outflow, which we identify with the observed jet, and an outer cold disk wind. While the former does not self-collimate efficiently due to its high effective inertia, the latter fulfills all the conditions for efficient collimation by the magneto-centrifugal mechanism. Given the right balance between the effective inertia of the inner flow and the collimation efficiency of the outer disk wind, the relativistic flow is magnetically confined into a well collimated beam for a wide range of parameters and matches the measurements of the opening angle of M87 over several orders of magnitude in spatial extent.In the second part of this work, we present synthetic synchrotron emission maps for our MHD models. In principle, the two-zone model can reproduce the morphological structure seen in radio observations, as central-peaked profiles across the jet close the the source, limb-bright further down the jet, and a bright knot close to the position of HST-1. However it is difficult to reconcile all features with a single set of parameters.

New results from the Event Horizon Telescope

“…New results from the Event Horizon Telescope Vincent Fish The apparent jet size is consistent with data at longer wavelengths (circles [17]) and general relativistic magnetohydrodynamic models of the larger jet (black line [18]) and inner jet (magenta and green lines, labelled by inclination to the line of sight [19]) that produce a parabolic profile for the jet width. The measured 1.3 mm size (dark blue line with 3σ range in cyan [4]) is significantly smaller than the lensed size of the ISCO for a non-spinning black hole (red line).…”