Deep X-ray and optical observations of quasar jets

Possibilities: Two related nuclei$ an interacting system? Several views of PKS 1421-490. A 20 GHz ATCA image !a# defines the structure. A new HST/ACS image in the F814W filter !b# shows no structure at all except for A and B, which appear to be pointlike !this needs to be verified#. A true-color optical image !c# constructed from SDSS i’, r’, and g’ images taken with Magellan. A 0.5-7.0 keV Chandra ACIS image !d# from our new, deeper !54 ks# observation showing diffuse flux in a wide swath between A and B. The FWHM of the respective PSFs are illustrated within a 1” square box. Models fitted to the spectral energy distributions !SEDs# of regions A and B. The model applied to A is typical of quasar cores: synchrotron emission from a jet with bulk motion of Γ = 20 at 2.9° to the line of sight, radius r = 4 pc, an electron distribution from γmin = 20 to γmax = 1.3 × 104 with a break at γ = 1.6 × 103, and Beq = 13 mG. An SSC model with B = Beq can match the observed X-ray flux if it is relativistically beamed. For region B an assumption of no self-absorption forces us to use a narrow range of electron energies !1.6 × 104 < γ < 2 × 106#, with Beq = 0.85 mG and a r = 0.4 kpc. SSC models fall orders of magnitude below the observed X-ray flux, which may be most readily explained by an ad hoc second population of synchrotronemitting electrons !Gelbord et al. 2005, ApJ 632, L75#.