Space VLBI Observations Show $T_b>10^{12}K$ in the Quasar NRAO 530

Abstract

We present here space-based VLBI observations with VSOP and a southern hemisphere ground array of the gamma-ray blazar NRAO 530 at 1.6 GHz and 5 GHz. The brightness temperature of the core at 1.6 GHz is $5\times 10^{11}$ K. The size is near the minimum observable value in the direction of NRAO~530 due to interstellar scattering. The 5 GHz data show a single component with a brightness temperature of $\sim 3\times 10^{12}$ K, significantly in excess of the inverse Compton limit and of the equipartition brightness temperature limit (Readhead 1994). This is strong evidence for relativistic motion in a jet requiring model-dependent Doppler boosting factors in the range 6 to 60. We show that a simple homogeneous sphere probably does not model the emission region accurately. We favor instead an inhomogeneous jet model with a Doppler boosting factor of 15.

12 pages, 2 figures. Accepted for publication in ApJ Letters

References in corpus (1)

• Sub-milliarcsecond Imaging of Quasars and AGN

Cited by in corpus (14)

• First M87 Event Horizon Telescope Results. VII. Polarization of the Ring
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• The Size, Shape, and Scattering of Sagittarius A* at 86 GHz: First VLBI with ALMA
• Circular Polarization of Radio Emission from Relativistic Jets
• NGC4258: a jet-dominated low-luminosity AGN?
• Kinematics of the Parsec-Scale Relativistic Jet in Quasar 3C 279: 1991 - 1997
• EHT-HOPS pipeline for millimeter VLBI data reduction
• Persistent Non-Gaussian Structure in the Image of Sagittarius A* at 86 GHz
• High-frequency very long baseline interferometry studies of NRAO 530
• A Short Hard X-ray Flare from the Blazar NRAO 530 Observed by INTEGRAL
• Radiative Hydromagnetic Shocks in Relativistic Outflow Sources
• Multi-Frequency VLBI Observations of NRAO 530
• Milliarcsecond-Scale Structure in the Gamma-Ray Loud Quasar PKS 1622-297
• The wavelength dependence of Sgr A* size and the unified model of compact radio sources