NuSTAR DETECTION OF THE BLAZAR B2 1023+25 AT REDSHIFT 5.3

作者：Sbarrato T^*; Tagliaferri G; Ghisellini G; Perri M; Puccetti S; Balokovic M; Nardini M; Stern D; Boggs S E; Brandt W N; Christensen F E; Giommi P; Greiner J; Hailey C J; Harrison F A; Hovatta T; Madejski G M; Rau A; Schady P; Sudilovsky V; Urry C M; Zhang W W

来源：Astrophysical Journal, 2013, 777(2): 147.

DOI：10.1088/0004-637X/777/2/147

• galaxies: active
• quasars: general
• quasars: individual (B2 1023+25)
• X-rays: general

B2 1023+ 25 is an extremely radio-loud quasar at z = 5.3 that was first identified as a likely high-redshift blazar candidate in the SDSS+ FIRST quasar catalog. Here, we use the Nuclear Spectroscopic Telescope Array (NuSTAR) to investigate its non-thermal jet emission, whose high-energy component we detected in the hard X-ray energy band. The X-ray flux is similar to 5.5 x 10(-14) erg cm(-2) s(-1) (5-10 keV) and the photon spectral index is Gamma(X) similar or equal to 1.3-1.6. Modeling the full spectral energy distribution, we find that the jet is oriented close to the line of sight, with a viewing angle of similar to 3 degrees, and has significant Doppler boosting, with a large bulk Lorentz factor similar to 13, which confirms the identification of B2 1023+ 25 as a blazar. B2 1023+ 25 is the first object at redshift larger than 5 detected by NuSTAR, demonstrating the ability of NuSTAR to investigate the early X-ray universe and to study extremely active supermassive black holes located at very high redshift.

• 出版日期2013-11-10