A relationship between agn jet power and radio power

Abstract

Using Chandra X-ray and Very Large Array radio data, we investigate the scaling relationship between jet power, Pjet, and synchrotron luminosity, Pradio. We expand the sample presented in Bîrzan et al. to lower radio power by incorporating measurements for 21 giant elliptical galaxies (gEs) to determine if the Bîrzan et al. Pjet-P radio scaling relations are continuous in form and scatter from gEs up to brightest cluster galaxies. We find a mean scaling relation of P jet ≈ 5.8 × 1043(Pradio/10 40)0.70 erg s-1 which is continuous over ∼6-8 decades in Pjet and Pradio with a scatter of ≈ 0.7 dex. Our mean scaling relationship is consistent with the model presented in Willott et al. if the typical fraction of lobe energy in non-radiating particles to that in relativistic electrons is ≳100. We identify several gEs whose radio luminosities are unusually large for their jet powers and have radio sources which extend well beyond the densest parts of their X-ray halos. We suggest that these radio sources are unusually luminous because they were unable to entrain appreciable amounts of gas.