The Most Compact Bright Radio-loud AGNs. II. VLBA Observations of 10 Sources at 43 and 86 GHz
Journal article, 2018

Radio-loud active galactic nuclei (AGNs), hosting powerful relativistic jet outflows, provide an excellent laboratory for studying jet physics. Very long baseline interferometry (VLBI) enables high-resolution imaging on milli-arcsecond (mas) and sub-mas scales, making it a powerful tool to explore the inner jet structure, shedding light on the formation, acceleration, and collimation of AGN jets. In this paper, we present Very Long Baseline Array observations of 10 radio-loud AGNs at 43 and 86 GHz that were selected from the Planck catalog of compact sources and are among the brightest in published VLBI images at and below 15 GHz. The image noise levels in our observations are typically 0.3 and 1.5 mJy beam -1 at 43 and 86 GHz, respectively. Compared with the VLBI data observed at lower frequencies from the literature, our observations with higher resolutions (with the highest resolution being up to 0.07 mas at 86 GHz and 0.18 mas at 43 GHz) and at higher frequencies detected new jet components at sub-parsec scales, offering valuable data for studies of the physical properties of the innermost jets. These include the compactness factor of the radio structure (the ratio of core flux density to total flux density), and core brightness temperature (T b ). In all these sources, the compact core accounts for a significant fraction ( > 60%) of the total flux density. Their correlated flux density at the longest baselines is higher than 0.16 Jy. The compactness of these sources make them good phase calibrators of millimeter-wavelength ground-based and space VLBI.

galaxies: jets

quasars: general

techniques: high angular resolution


galaxies: active


X. P. Cheng

Shanghai Astronomical Observatory

Chinese Academy of Sciences

T. An

Chinese Academy of Sciences

Shanghai Astronomical Observatory

X. Y. Hong

Shanghai Astronomical Observatory

Chinese Academy of Sciences

Jun Yang

Shanghai Astronomical Observatory

Chalmers, Space, Earth and Environment, Onsala Space Observatory

P. Mohan

Shanghai Astronomical Observatory

K. I. Kellermann

National Radio Astronomy Observatory

M. L. Lister

Purdue University

S. Frey

Hungarian Academy of Sciences

W. Zhao

Shanghai Astronomical Observatory

Z. L. Zhang

Shanghai Astronomical Observatory

Xiaocong Wu

Shanghai Astronomical Observatory

X. F. Li

Chinese Academy of Sciences

Shanghai Astronomical Observatory

Y. K. Zhang

Shanghai Astronomical Observatory

Chinese Academy of Sciences

Astrophysical Journal, Supplement Series

0067-0049 (ISSN) 1538-4365 (eISSN)

Vol. 234 1 17

Subject Categories

Astronomy, Astrophysics and Cosmology

Other Physics Topics

Fusion, Plasma and Space Physics



More information

Latest update

7/4/2018 7