The M87 Jet
نویسندگان
چکیده
We investigate the structure and dynamics of the M87 jet based on multi-frequency VLBI observations and MHD jet theories. Millimeter VLBI cores are considered as innermost jet emissions. The jet structure up to ∼ 105 rs is described as a parabolic streamline, indicating the lateral expansion under a confinement by the stratified ISM. Thus, the jet collimation maintains in five orders of magnitude in the distance starting from the vicinity of the supermassive black hole (SMBH), less than 10 rs. We here examine the jet parabolic structure in order to identify the property of a bulk acceleration; observed sub-to-superluminal motions indicate an MHD acceleration from non-relativistic to relativistic regimes. We propose that the M87 jet consists of Poynting-flux dominated flows, powered by nonlinear torsional Alfvén waves. Future sub-mm VLBI observations play an important role in resolving the origin of the M87 jets.
منابع مشابه
A Modified Synchrotron Model for Knots in the M87 Jet
For explaining the broadband spectral shape of knots in the M87 jet from radio through optical to X-ray, we propose a modified synchrotron model that considers the integrated effect of particle injection from different acceleration sources in the thin acceleration region. This results in two break frequencies at two sides of which the spectral index of knots in the M87 jet changes. We discuss t...
متن کاملDetermination of the intrinsic velocity field in the M87 jet
A new method to estimate the Doppler beaming factor of relativistic large-scale jet regions is presented. It is based on multiwaveband fitting to radio-to-X-ray continua with synchrotron spectrum models. Combining our method with available observational data of proper motions, we derive the intrinsic velocity as well as the viewing angles to the line of sight for eight knotty regions down the M...
متن کاملThe inner jet of the radio galaxy M87
We report new 2 cm VLBA images of the inner radio jet of M87 showing a limb-brightened structure and unambiguous evidence for a faint 3 mas long counterfeature which also appears limb brightened. Multiepoch observations of seven separate jet features show typical speeds of less than a few percent of the speed of light, despite the highly asymmetric jet structure and the implications of the cano...
متن کاملImaging the Black Hole Silhouette of M87: Implications for Jet Formation and Black Hole Spin
The silhouette cast by the horizon of the supermassive black hole in M87 can now be resolved with the emerging millimeter very-long baseline interferometry (VLBI) capability. Despite being ∼ 2× 10 times farther away than Sgr A* (the supermassive black hole at the center of the Milky-Way and the primary target for horizon-scale imaging), M87’s much larger black hole mass results in a horizon ang...
متن کاملThe Event Horizon of M87
The M 6 109 × ⊙ supermassive black hole at the center of the giant elliptical galaxy M87 powers a relativistic jet. Observations at millimeter wavelengths with the Event Horizon Telescope have localized the emission from the base of this jet to angular scales comparable to the putative black hole horizon. The jet might be powered directly by an accretion disk or by electromagnetic extraction of...
متن کامل