Confronting X‐Ray Emission Models with the Highest Redshift Kiloparsec‐Scale Jets: Thez = 3.89 Jet in Quasar 1745+624

Abstract

A newly identified kiloparsec-scale X-ray jet in the high-redshift z ¼ 3:89 quasar 1745+624 is studied with multifrequency radio, HST, and Chandra X-ray imaging data. This is only the third large-scale X-ray jet beyond z > 3 known and is further distinguished as being the most luminous relativistic jet observed at any redshift, exceeding 10 45 ergs s À1 in both the radio and X-ray bands. Apart from the jet's extreme redshift and luminosity, its basic properties, such as X-ray/radio morphology, radio polarization, and the convex broadband spectral energy distributions of three distinct knots are also similar to lower z examples. Relativistically beamed inverse Compton and ''nonstandard'' synchrotron models have been considered to account for such excess X-ray emission in other jets; both models are applicable here, but with differing requirements for the underlying jet physical properties, such as velocity, energetics, and electron acceleration processes. One potentially very important distinguishing characteristic between the two models is their strongly diverging predictions for the X-ray/radio emission with increasing redshift. This is considered, although with the limited sample of three z > 3 jets it is apparent that future studies targeted at very highredshift jets are required for further elucidation. Finally, from the broadband jet emission we estimate the jet kinetic power to be no less than 10 46 ergs s À1 , which is about 10% of the Eddington luminosity corresponding to this galaxy's central supermassive black hole mass M BH k10 9 M estimated here via the virial relation. The optical luminosity of the quasar core is about 10 times over Eddington, hence the inferred jet power seems to be much less than that available from mass accretion. The apparent super-Eddington accretion rate may, however, suggest contribution of an unresolved jet in the observed optical nucleus.

DISCOVERY OF A KILOPARSEC-SCALE X-RAY/RADIO JET IN THE z = 4.72 QUASAR GB 1428+4217

“…These estimates assume a single X-ray/radio emitting zone applies to our ∼ 1 ′′ (6.6 kpc) angular resolution element. Similarly applying the IC/CMB model to the other high-redshift X-ray jet, GB 1508+4714 (z = 4.3; Cheung 2004) and 1745+624 (z = 3.9; Cheung et al 2006), they derived δ ∼ 3 − 5. These values are smaller than the typical ones (δ ∼ 5 − 10) determined for lower-redshift jets (e.g., Kataoka & Stawarz 2005).…”

HUBBLE SPACE TELESCOPEOBSERVATIONS OF THE QUASAR PKS 0637-752: EQUIPARTITION ELECTRON-PROTON JET FROM THE MOST COMPLETE SPECTRAL COVERAGE TO DATE

“…Further X-ray studies using Chandra have confirmed that bright X-ray emitting jets are common among radio-loud quasars and radio galaxies (e.g. Sambruna et al 2002Sambruna et al , 2004Sambruna et al , 2006Marshall et al 2005;Siemiginowska et al 2002;Kataoka et al 2003;Jorstad et al 2004;Cheung, Stawarz, & Siemiginowska 2006;Schwartz et al 2006). They also confirmed that in these jets the X-ray emission is a spectral component separate from the radio optical synchrotron emission, with the X-ray flux being higher that that anticipated by simply extending the radio-optical spectrum to X-ray energies.…”

A Giant Radio Jet Ejected by an Ultramassive Black Hole in a Single-lobed Radio Galaxy

“…An independent estimate of is obtained using the fol-M BH lowing relation (Marconi & Hunt 2003): and also the quasar 1745ϩ624 (Cheung et al 2006)]. 2.…”