Intrinsic Brightness Temperature of Compact Radio Sources at 86 GHz

Abstract

We present results on the intrinsic brightness temperature of a sample of compact radio sources observed at 86 GHz using the Global Millimeter VLBI Array. We use the observed brightness temperatures at 86 GHz and the observed superluminal motions at 15 GHz for the sample in order to constrain the characteristic intrinsic brightness temperature of the sample. With a statistical method for studying the intrinsic brightness temperatures of innermost jet cores of compact radio sources, assuming that all sources have the same intrinsic brightness temperature and the viewing angles of their jets are around the critical value for the maximal apparent speed, we find that sources in the sample have a characteristic intrinsic brightness temperature, $T_0=4.8_{-1.5}^{+2.6}\times 10^9$ K, which is lower than the equipartition temperature for the condition that the particle energy equals to the magnetic field energy. Our results suggest that the VLBI cores seen at 86 GHz may be representing a jet region where the magnetic field energy dominates the total energy in the jet.

9 pages, 4 figures, one table, to appear in JKAS. Corrections made for typos and Journal's further requests

References in corpus (6)

• Sub-milliarcsecond Imaging of Quasars and Active Galactic Nuclei III. Kinematics of Parsec-Scale Radio Jets
• A change in the optical polarization associated with a gamma-ray flare in the blazar 3C 279
• Relativistic Beaming and the Intrinsic Properties of Extragalactic Radio Jets
• A Global 86GHz VLBI Survey of Compact Radio Sources
• Intrinsic Brightness Temperatures of AGN Jets
• Compact jets as probes for sub-parsec scale regions in AGN

Cited by in corpus (7)

• MOJAVE XIX: Brightness Temperatures and Intrinsic Properties of Blazar Jets
• Magnetization degree at the jet base of M87 derived from the event horizon telescope data: Testing magnetically driven jet paradigm
• PKS 1502+106: A high-redshift Fermi blazar at extreme angular resolution. Structural dynamics with VLBI imaging up to 86 GHz
• Acceleration of Compact Radio Jets on Sub-parsec Scales
• Interferometric Monitoring of Gamma-ray Bright AGNs I: Results of Single-epoch Multifrequency Observations
• The Event Horizon Telescope Image of the Quasar NRAO 530
• Up around the bend: a multi-wavelength view of the quasar 3C 345