TY - JOUR
AU - Gurvits, Leonid I.
AB - The extremely high-redshift (z5.3) radio source SDSS J102623.61254259.5 (J10262542) is among the most distant and most luminous radio-loud active galactic nuclei (AGN) known to date. Its one-sided radio jet structure on milliarcsecond (mas) and10-mas scales typical for blazars was first imaged at 5GHz with very long baseline interferometry (VLBI) in 2006. Here we report on our dual-frequency (1.7 and 5GHz) imaging observations performed with the European VLBI Network (EVN) in 2013. The prominent jet structure allows us to identify individual components whose apparent displacement can be detected over the time span of 7.33yr. This is the first time when jet proper motions are directly derived in a blazar at z>5. The small values of up to0.1 masyr1 are consistent with what is expected in a relativistic cosmological model if redshift is a measure of distance. The apparent superluminal jet speeds, considered tentative because derived from two epochs only, exceed 10c for three different components along the jet. Based on modelling its spectral energy distribution, J10262542 is known to have its X-ray jet oriented close to the line of sight, with significant Doppler boosting and a large bulk Lorentz factor (13). The new VLBI observations, indicating2.31012K lower limit to the core brightness temperature, are consistent with this picture. The spectral index in the core region is0.35.
TI - The first estimate of radio jet proper motion at z>5
JF - Monthly Notices of the Royal Astronomical Society
DO - 10.1093/mnras/stu2294
DA - 2014-11-29
UR - https://www.deepdyve.com/lp/oxford-university-press/the-first-estimate-of-radio-jet-proper-motion-at-z-5-PLFKkJLPmn
SP - 2921
EP - 2928
VL - 446
IS - 3
DP - DeepDyve
ER -