Standardizing reverberation-measured C iv time-lag quasars, and using them with standardized Mg ii quasars to constrain cosmological parameters
| Authors | |
|---|---|
| Year of publication | 2022 |
| Type | Article in Periodical |
| Magazine / Source | Monthly Notices of the Royal Astronomical Society |
| MU Faculty or unit | |
| Citation | |
| Web | |
| Doi | http://dx.doi.org/10.1093/mnras/stac2325 |
| Keywords | quasars: emission lines; cosmological parameters; cosmology: observations; dark energy |
| Description | We use 38 C?IV quasar (QSO) reverberation-mapped observations, which span eight orders of magnitude in luminosity and the redshift range 0.001064 ? z ? 3.368, to simultaneously constrain cosmological-model and QSO radius–luminosity (R–L) relation parameters in six cosmological models, using an improved technique that more correctly accounts for the asymmetric errors bars of the time-lag measurements. We find that R–L relation parameters are independent of the cosmological models used in the analysis and so the R–L relation can be used to standardize the C?IV QSOs. The C?IV QSO cosmological constraints are consistent with those from Mg?II QSOs, allowing us to derive joint C?IV + Mg?II QSO cosmological constraints which are consistent with currently accelerated cosmological expansion, as well as consistent with cosmological constraints derived using better-established baryon acoustic oscillation (BAO) and Hubble parameter [H(z)] measurements. When jointly analysed with H(z) + BAO data, current C?IV + Mg?II QSO data mildly tighten current H(z) + BAO data cosmological constraints. |
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