2017/01/30 by G. A. Khorunzhev, Г. А. Хорунжев, R. Burenin +6 · 1 citation
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #Galaxy #Observatory #Physics #Quasar #Redshift #Solar observatory #Spectral line #Spectrograph #Spectroscopy #Telescope #X-ray telescope #acm:85A04 #acm:85A35 #astro-ph.GA #astro-ph.IM #msc:85A04 #msc:85A35
paper · pdf · doi:10.1134/s1063773717030045
published as Astron. Lett. (2017) 43: 135 · russian text in Pisma v astronomicheskii Zhurnal (2017) 43: 159
arxiv created 2017/01/30 · arxiv updated 2017/02/01 · openalex created_date 2017/02/10 · openalex publication_date 2017/03/01 · openalex updated_date 2026/08/05
We present the results of optical spectroscopy for 19 quasar candidates at photometric redshifts z phot ≳ 3, 18 of which enter into the Khorunzhev et al. (2016) catalog (K16). This is a catalog of quasar candidates and known type 1 quasars selected among the X-ray sources of the 3XMM-DR4 catalog of the XMM-Newton serendipitous survey. We have performed spectroscopy for a quasi-random sample of new candidates at the 1.6-m AZT-33IK telescope of the Sayan Solar Observatory and the 6-m BTA telescope of the Special Astrophysical Observatory. The spectra at AZT-33IK were taken with the new low- and medium-resolution ADAM spectrograph that was produced and installed on the telescope in 2015. Fourteen of the 18 candidates actually have turned out to be quasars; 10 of them are at spectroscopic redshifts z spec > 3. The high purity of the sample of new candidates suggests that the purity of the entire K16 catalog of quasars is probably 70–80%. One of the most distant (z spec = 5.08) optically bright (i′ ≲ 21) quasars ever detected in X-ray surveys has been discovered.