Milli-arcsecond--scale Spectral Properties and Jet Motions in M87

Abstract

We have combined high resolution VLBI Space Observatory Programme (VSOP) data at 1.6 and 4.8 GHz with Very Long Baseline Array (VLBA) data at higher frequencies and with similar resolutions to study the spectral properties of the core of M87 with milliarcsecond resolution. The VSOP data allow a more accurate measurement of the turn-over frequency, and hence more reliable determination of associated physical parameters of the source. Comparison of the images with previously published images yields no evidence for significant motion of components in the parsec-scale jet. In addition, the brightness temperatures obtained from model-fits to the core are well below the inverse Compton limit, suggesting the radio emission we are observing is not strongly Doppler boosted. Colour version on http://www.vsop.isas.jaxa.jp/survey/publications/m87.ps.gz

To appear in PASJ VSOP special issue. Minor corrections

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• Are Cen a and M87 Tev Gamma-Ray Sources?
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Cited by in corpus (26)

• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• Kinematics of the jet in M87 on scales of 100 -- 1000 Schwarzschild radii
• The Inner Jet of the Radio Galaxy M87
• High-Sensitivity 86GHz (3.5mm) VLBI Observations of M87: Deep Imaging of the Jet Base at a 10 Schwarzschild-Radius Resolution
• Dynamics and High Energy Emission of the Flaring HST-1 Knot in the M 87 Jet
• Superluminal Radio Features in the M87 Jet and the Site of Flaring TeV Gamma-ray Emission
• High Frequency VLBI Imaging of the Jet Base of M87
• Innermost collimation structure of the M87 jet down to ~ten Schwarzschild radii
• 230 GHz VLBI observations of M87: event-horizon-scale structure at the enhanced very-high-energy $\gamma$-ray state in 2012
• Discovery of Sub- to Superluminal Motions in the M87 Jet: An Implication of the Acceleration from Sub-relativistic to Relativistic Speeds
• High Precision Astrometric Millimeter VLBI Using a New Method for Atmospheric Calibration
• Kinematics of the M87 jet in the collimation zone: gradual acceleration and velocity stratification
• Magnetization degree at the jet base of M87 derived from the event horizon telescope data: Testing magnetically driven jet paradigm
• Pilot KaVA monitoring on the M87 jet: confirming the inner jet structure and superluminal motions at sub-pc scales
• A strong radio brightening at the jet base of M87 during the elevated very-high-energy gamma-ray state in 2012
• Determination of the intrinsic velocity field in the M87 jet
• Relativistic electrons and magnetic field of the M87 jet on ~ten Schwarzschild radii scale
• Using Radio Bubbles to Constrain the Matter Content of AGN Jets
• Monitoring the Bi-Directional Relativistic Jets of the Radio Galaxy 3C 338
• Spectral analysis of a parsec-scale jet in M87: Observational constraint on the magnetic field strengths in the jet
• High Resolution Radio Astronomy Using Very Long Baseline Interferometry
• RadioAstron Space VLBI Imaging of the jet in M87: I. Detection of high brightness temperature at 22 GHz
• Probing the central black hole in M87 with gamma-rays
• M87: a cosmic laboratory for deciphering black hole accretion and jet formation
• CLEAN imaging systematics of M87 radio jet
• Direct time radio variability induced by non-axisymmetric standing accretion shock instability: implications for M87