A Statistical Description of AGN Jet Evolution from the VLBA Imaging and Polarimetry Survey (VIPS)

TL;DR

This paper analyzes the evolution and alignment of AGN jets using VLBA and VLA data, revealing power-law relationships, minimal energy loss, and gradual realignment of jets over parsec to kiloparsec scales.

Contribution

It provides a detailed statistical description of AGN jet properties and their evolution, highlighting jet alignment and realignment patterns across different scales.

Findings

Jet intensity follows a power-law with width, indicating little energy loss.

Parsec-scale jets tend to align with kiloparsec-scale emission directions.

Jets show gradual realignment with small bending angles (~5 degrees).

Abstract

A detailed analysis of the evolution of the properties of core-jet systems within the VLBA Imaging and Polarimetry Survey (VIPS) is presented. We find a power-law relationship between jet intensity and width that suggests for the typical jet, little if any energy is lost as it moves away from its core. Using VLA images at 1.5 GHz, we have found evidence that parsec-scale jets tend to be aligned with the the direction of emission on kiloparsec scales. We also found that this alignment improves as the jets move farther from their cores on projected scales as small as ~50-100 pc. This suggests that realignment of jets on these projected scales is relatively common. We typically find a modest amount of bending (a change in jet position angle of ~5 deg.) on these scales, suggesting that this realignment may typically occur relatively gradually.