Two Candidate High-redshift X-Ray Jets without Coincident Radio Jets
D. A. Schwartz, A. Siemiginowska, B. Snios, D. M. Worrall, M. Birkinshaw, C. C. Cheung, H. Marshall, G. Migliori, J. F. C. Wardle, Doug Gobeille
Abstract
Abstract We report the detection of extended X-ray emission from two high-redshift radio quasars. These quasars, J1405+0415 at z = 3.208 and J1610+1811 at z = 3.118, were observed in a Chandra snapshot survey selected from a complete sample of the radio-brightest quasars in the overlap area of the VLA-FIRST radio survey and the Sloan Digital Sky Survey. The extended X-ray emission is located along the line connecting the core to a radio knot or hotspot, favoring the interpretation of X-ray jets. The inferred rest-frame jet X-ray luminosities from 2 to 30 keV would be of order 10 45 erg s −1 if emitted isotropically and without relativistic beaming. In the scenario of inverse Compton scattering of the cosmic microwave background (CMB), X-ray jets without a coincident radio counterpart may be common, and should be readily detectable to redshifts even beyond 3.2 due to the (1+ z ) 4 increase of the CMB energy density compensating for the (1+ z ) −4 cosmological diminution of surface brightness. If these can be X-ray confirmed, they would be the second and third examples of quasar X-ray jets without detection of underlying continuous radio jets.