The Origins of X-Ray Emission from the Hot Spots of FR II Radio Sources

By M. Hardcastle, D. Harris, D. Worrall, M. Birkinshaw. 2004

147 citations recorded by the source corpus.

We use new and archival Chandra data to investigate the X-ray emission from a large sample of compact hot spots of FR II radio galaxies and quasars from the 3C catalog. We find that only the most luminous hot spots tend to be in good agreement with the predictions of a synchrotron self-Compton model with equipartition magnetic fields. At low hot spot luminosities inverse Compton predictions are routinely exceeded by several orders of magnitude, but this is never seen in more luminous hot spots. We argue that an additional synchrotron component of the X-ray emission is present in low-luminosity hot spots and that the hot spot luminosity controls the ability of a given hot spot to produce synchrotron X-rays, probably by determining the high-energy cutoff of the electron energy spectrum. It remains plausible that all hot spots are close to the equipartition condition.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/0b0db9de22d79eb7e7af4e99b5cf4e498cb2b4e6

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Citations in the corpus

Radio galaxies and feedback from AGN jets (2020, background): “Observations of inverse-Compton emission from the lobes and hotspots of FRII RLAGN (Hardcastle et al., 2002, 2004; Kataoka and Stawarz, 2005; Croston et al., 2005; Ineson et al., 2017) measure the number of inverse-Compton-scattering electrons and so allow the characteristic magnetic field strength…”
FERMI LARGE AREA TELESCOPE OBSERVATIONS OF MISALIGNED ACTIVE GALACTIC NUCLEI (2010, background): “For the MAGNs quoted in Morganti et al. (1993) and Burgess & Hunstead (2006a, 2006b), the reported 5 GHz core fluxes density are K-corrected using αcore = 0, while for the extended component the correction has been performed using the spectral index listed in those papers.”
An X-Ray Study of Magnetic Field Strengths and Particle Content in the Lobes of FR II Radio Sources (2005, methodology): “The electron density scales as V −4/7 (Hardcastle et al. 2004), so that the predicted X-ray flux Scmb ∝ V 3/7.”
X-Ray Emission from Extragalactic Jets (2006, background): “This excess could be attributed to a field strength well below equipartition, IC emission from the decelerating jet ’seeing’ Doppler boosted hotspot emission (Georganopoulos & Kazanas 2003), or an additional synchrotron component (Hardcastle et al. 2004a).”
X-Ray Emission Properties of Large-Scale Jets, Hot Spots, and Lobes in Active Galactic Nuclei (2004, background): “…in many objects this emission is consistent with the standard SSC model (see, e.g., Wilson et al. 2000 for Cygnus A), in some other sources it cannot be simply explained in this way, suggesting most likely a synchrotron origin of the detected X-ray photons (see, e.g., Hardcastle et al. 2004).”