出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Based on the VLBI Space Observatory Programme (VSOP) observations at 1.6 and 5 GHz, we
find that the luminous high-redshift (z = 3.215) quasar PKS 1402+044 (J1405+0415) has a pronounced
“core–jet” structure. The jet shows a steeper spectral index and lower brightness temperature
with the increase of the distance from the core. The variation of brightness temperature
is basically consistent with the shock-in-jet model. Assuming that the jet is collimated by the
ambient magnetic field, we estimate the mass of the central object as ∼ 109M⊙. The upper limit
of the jet proper motion of PKS 1402+044 is 0.03 mas yr−1 (∼ 3c) in the east-west direction.
