The Classification of Extragalactic X-ray Jets

TL;DR

This paper analyzes the X-ray emission mechanisms of extragalactic jets, classifying them based on flux ratios and correlations with jet parameters, aiming to refine understanding beyond traditional radio-based classifications.

Contribution

It introduces a systematic analysis of X-ray to radio flux ratios for a large sample of jets, exploring correlations with jet parameters to better understand emission mechanisms.

Findings

X-ray to radio flux ratios vary with jet type and orientation.

Correlations suggest different emission processes like synchrotron and IC/CMB.

Initial results support the classification framework based on flux ratios.

Abstract

The overall classification of X-ray jets has clung to that prevalent in the radio: FRI vs. FRII (including quasars). Indeed, the common perception is that X-ray emission from FRI's is synchrotron emission whereas that from FRII's may be IC/CMB and/or synchrotron. Now that we have a sizable collection of sources with detected X-ray emission from jets and hotspots, it seems that a more unbiased study of these objects could yield additional insights on jets and their X-ray emission. The current contribution is a first step in the process of analyzing all of the relevant parameters for each detected component for the sources collected in the XJET website. This initial effort involves measuring the ratio of X-ray to radio fluxes and evaluating correlations with other jet parameters. For single zone synchrotron X-ray emission, we anticipate that larger values of fx/fr should correlate inversely with the average magnetic field strength (if the acceleration process is limited by loss time equals acceleration time). Beamed IC/CMB X-rays should produce larger values of fx/fr for smaller values of the angle between the jet direction and the line of sight but will also be affected by the low frequency radio spectral index.