摘要
Recently, two classes of quasar samples were identified, which are promising as new cosmological probes extending to higher redshifts. The first sample uses the nonlinear relation between the ultraviolet and X-ray luminosities of quasars to derive luminosity distances, whereas the linear sizes of compact radio quasars in the second sample can serve as standardized rulers, providing angular-diameter distances. In this study, under the assumption of a flat universe, we refreshed the calibration of multiple measurements of high-redshift quasars(in the framework of a cosmological-model-independent method with the newest Hubble parameters data). Furthermore, we placed constraints on four models that characterize the cosmic equation of state(w). The obtained results show that:(1) the two quasar samples could provide promising complementary probes at much higher redshifts,whereas compact radio quasars perform better than ultraviolet and X-ray quasars at the current observational level;(2) strong degeneracy between the cosmic equation of state(w) and Hubble constant(H0) is revealed, which highlights the importance of independent determination of H0 from time-delay measurements of strongly lensed quasars;(3) together with other standard ruler probes, such as baryon acoustic oscillation distance measurements, the combined QSO+BAO measurements are consistent with the standard ΛCDM model at a constant equation of state w =-1;(4) ranking the cosmological models, the polynomial parametrization gives a rather good fit among the four cosmic-equation-of-state models, whereas the Jassal-Bagla-Padmanabhan(JBP) parametrization is substantially penalized by the Akaike Information Criterion and Bayesian Information Criterion.
基金
supported by the National Natural Science Foundation of China(Grant Nos.12021003,11690023,11633001,and 11920101003)
supported by the National Natural Science Foundation of China(Grant Nos.11947091,and 12003006)
the National Key R&D Program of China(Grant No.2017YFA0402600)
the Beijing Talents Fund of Organization Department of Beijing Municipal Committee of the CPC
the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB23000000)
the Opening Project of Key Laboratory of Computational Astrophysics,National Astronomical Observatories,Chinese Academy of Sciences
the Interdiscipline Research Funds of Beijing Normal University
supported by the Foreign Talent Introducing Project and Special Fund Support of Foreign Knowledge Introducing Project in China,the Key Foreign Expert Program for the Central Universities(Grant No.X2018002)
the Natural Science Foundation of Hebei(Grant No.A202005002)。