Independent cosmological constraints from highz H II galaxies: new results from VLTKMOS data
Abstract
We present independent determinations of cosmological parameters using the distance estimator based on the established correlation between the Balmer line luminosity, L(H β), and the velocity dispersion (σ) for H II galaxies (HIIG). These results are based on new VLTKMOS high spectral resolution observations of 41 highz (1.3 ≤ z ≤2.6) HIIG combined with published data for 45 highz and 107 z ≤0.15 HIIG, while the cosmological analysis is based on the MultiNest Markov Chain Monte Carlo (MCMC) procedure not considering systematic uncertainties. Using only HIIG to constrain the matter density parameter (Ω_{m}), we find $\Omega _\mathrm{ m} = 0.244^{+0.040}_{0.049}$ (stat), an improvement over our best previous cosmological parameter constraints, as indicated by a 37 per cent increase of the figure of merit. The marginalized bestfitting parameter values for the plane {Ω_{m}; w_{0}} = $\lbrace 0.249^{+0.11}_{0.065}; 1.18^{+0.45}_{0.41}\rbrace$ (stat) show an improvement of the cosmological parameters constraints by 40 per cent. Combining the HIIG Hubble diagram, the cosmic microwave background (CMB) and the baryon acoustic oscillation (BAO) probes yields Ω_{m} = 0.298 ± 0.012 and w_{0} = 1.005 ± 0.051, which are certainly compatible  although less constraining  than the solution based on the joint analysis of Ia supernovae (SNIa), CMB and BAO measurements. An attempt to constrain the evolution of the dark energy with time (CPL model), using a joint analysis of the HIIG, CMB, and BAO measurements, shows a degenerate 1σ contour of the parameters in the {w_{0}, w_{a}} plane.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 July 2021
 DOI:
 10.1093/mnras/stab1385
 arXiv:
 arXiv:2105.04025
 Bibcode:
 2021MNRAS.505.1441G
 Keywords:

 galaxies: starburst;
 cosmological parameters;
 observations;
 dark energy;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 Accepted to be published in the main journal of the Monthly Notices of the Royal Astronomical Society