Cosmological constraints from HII starburst galaxy apparent magnitude and other cosmological measurements

TL;DR

This study uses HII starburst galaxy data combined with other cosmological measurements to constrain parameters like matter density and Hubble constant, supporting a cosmological constant and flat geometry.

Contribution

It provides new constraints on cosmological parameters using a joint analysis of multiple observational data sets, including HII galaxy apparent magnitudes.

Findings

Lower H_0 estimates than local measurements.

Data consistent with a cosmological constant and flat universe.

Supports mild dark energy dynamics or slight non-flatness.

Abstract

We use HII starburst galaxy apparent magnitude measurements to constrain cosmological parameters in six cosmological models. A joint analysis of HII galaxy, quasar angular size, baryon acoustic oscillations peak length scale, and Hubble parameter measurements result in relatively model-independent and restrictive estimates of the current values of the non-relativistic matter density parameter $\Omega_{\rm m_0}$ and the Hubble constant $H_0$. These estimates favor a 2.0$\sigma$ to 3.4$\sigma$ (depending on cosmological model) lower $H_0$ than what is measured from the local expansion rate. The combined data are consistent with dark energy being a cosmological constant and with flat spatial hypersurfaces, but do not strongly rule out mild dark energy dynamics or slightly non-flat spatial geometries.