Multiwavelength and parsec-scale properties of extragalactic jets

TL;DR

This paper presents a multiwavelength, high-resolution VLBI study of extragalactic jets from active galaxies, revealing detailed jet kinematics, structure, and properties, especially focusing on the TANAMI sample and two specific sources.

Contribution

It provides the first VLBI images for most TANAMI sources, offering new insights into jet formation, composition, and emission mechanisms at parsec scales.

Findings

First VLBI images for most TANAMI sources.

Jet kinematics show acceleration and spine-sheath structure in Centaurus A.

Characterization of PMN J1603-4904 as an atypical blazar or gamma-ray loud radio galaxy.

Abstract

Extragalactic jets originating from the central supermassive black holes of active galaxies are powerful, highly relativistic plasma outflows, emitting light from the radio up to the gamma-ray regime. The details of their formation, composition and emission mechanisms are still not completely clear. The combination of high-resolution observations using very long baseline interferometry (VLBI) and multiwavelength monitoring provides the best insight into these objects. Here, such a combined study of sources of the TANAMI sample is presented, investigating the parsec-scale and high-energy properties. The TANAMI program is a multiwavelength monitoring program of a sample of the radio and gamma-ray brightest extragalactic jets in the southern sky, below -30deg declination. We obtain the first-ever VLBI images for most of the sources, providing crucial information on the jet kinematics and brightness distribution at milliarcsecond resolution. Two particular sources are discussed in detail: PMN J1603-4904, which can be classified either as an atypical blazar or a gamma-ray loud (young) radio galaxy, and Centaurus A, the nearest radio-loud active galaxy. The VLBI kinematics of the innermost parsec of Centaurus A's jet result in a consistent picture of an accelerated jet flow with a spine-sheath like structure.