Standardizing reverberation-measured Mg II time-lag quasars, by using the radius–luminosity relation, and constraining cosmological model parameters

Warning

This publication doesn't include Faculty of Sports Studies. It includes Faculty of Science. Official publication website can be found on muni.cz.
Authors

KHADKA Narayan YU Zhefu ZAJAČEK Michal MARTINEZ-ALDAMA Mary Loli CZERNY Bożena RATRA Bharat

Year of publication 2021
Type Article in Periodical
Magazine / Source Monthly Notices of the Royal Astronomical Society
MU Faculty or unit

Faculty of Science

Citation
Web https://doi.org/10.1093/mnras/stab2807
Doi http://dx.doi.org/10.1093/mnras/stab2807
Keywords cosmological parameters; cosmology: observations; dark energy; quasars: emission lines
Description We use 78 reverberation-measured Mg II time-lag quasars (QSOs) in the redshift range 0.0033 ? z ? 1.89 to constrain cosmological parameters in six different cosmological models. The basis of our method is the use of the radius–luminosity or R-L relation to standardize these 78 Mg II QSOs. In each cosmological model, we simultaneously determine R-L relation and cosmological model parameters, thus avoiding the circularity problem. We find that the R-L relation parameter values are independent of the cosmological model used in the analysis, thus, establishing that current Mg II QSOs are standardizable candles. Cosmological constraints obtained using these QSOs are significantly weaker than, but consistent with, those obtained from a joint analysis of baryon acoustic oscillation (BAO) observations and Hubble parameter [H(z)] measurements. So, we also analyse these QSOs in conjunction with the BAO + H(z) data and find cosmological constraints consistent with the standard spatially flat ?CDM model as well as with mild dark energy dynamics and a little spatial curvature. A larger sample of higher quality reverberation-measured QSOs should have a smaller intrinsic dispersion and so should provide tighter constraints on cosmological parameters.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.

More info