X-ray jets in radio-loud active galaxies

DM Worrall*

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)


Much can be learnt about the physics of the radio-emitting plasma in active galaxies through X-ray measurements. If inverse-Compton X-rays are seen from radio-emitting regions, the degeneracy between particle density and magnetic field strength can be broken, and if synchrotron X-rays are seen, key information is available concerning the highest-energy particles, those most subject to energy losses and thus most in need of re-acceleration. The Chandra X-ray Observatory routinely detects extended galaxy or cluster-scale X-ray emitting gas around radio-loud active galaxies, and this has a strong influence on overall source dynamics. In low-power (FRI) radio sources, resolved X-ray emission associated with the brighter, kpc-scale radio jet is commonly measured. There is good evidence that this X-ray jet emission is synchrotron in origin, and the short lifetimes of the TeV electrons involved means that considerable in situ particle acceleration is required. There are global similarities but small-scale differences in the radio and X-ray structures and spectra between sources, and this information can be used to probe details of the acceleration processes. The jets of high-power (FRII) radio sources are believed to slow down less, and propagate to kpc (and in some cases Mpc) distances at (at least mildly) relativistic speeds. Chandra results suggest that here inverse Compton processes are dominant in dictating the level of detected X-ray emission. In particular, in a number of hotspots and lobes the level of X-ray emission suggests that the structures are radiating at close to minimum energy, with similar total energy in relativistic particles and magnetic fields.

Original languageEnglish
Title of host publicationCosmology and Particle Astrophysics
Subtitle of host publicationProceedings of the 2002 International Symposium on CosPA 2002
EditorsX.-G He, K-W Ng
Place of PublicationSingapore
PublisherWorld Scientific Publishing Co.
Number of pages13
ISBN (Electronic)978-981-4486-58-3
ISBN (Print)978-981-238-284-9
Publication statusPublished - 1 Mar 2003
EventInternational Symposium on Cosmology and Particle Astrophysics - Taipei, United Kingdom
Duration: 31 May 20022 Jun 2002


ConferenceInternational Symposium on Cosmology and Particle Astrophysics
Country/TerritoryUnited Kingdom

Bibliographical note

Name and Venue of Event: CosPA 2002
Conference Proceedings/Title of Journal: Cosmology and Particle Astrophysics




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