A two-point diagnostic for the HII galaxy Hubble diagram

作者：Leaf Kyle^*; Melia Fulvio^*

来源：Monthly Notices of the Royal Astronomical Society, 2018, 474(4): 4507-4513.

DOI：10.1093/mnras/stx3109

• galaxies: general
• distance scale
• large-scale structure of Universe
• cosmology: observations
• cosmology: theory

A previous analysis of starburst-dominated HII galaxies and HII regions has demonstrated a statistically significant preference for the Friedmann-Robertson-Walker cosmology with zero active mass, known as the R-h = c(t) universe, over Lambda cold dark matter (Lambda CDM) and its related dark-matter parametrizations. In this paper, we employ a two-point diagnostic with these data to present a complementary statistical comparison of Rh = ct with Planck Lambda CDM. Our two-point diagnostic compares, in a pairwise fashion, the difference between the distance modulus measured at two redshifts with that predicted by each cosmology. Our results support the conclusion drawn by a previous comparative analysis demonstrating that Rh = ct is statistically preferred over Planck Lambda CDM. But we also find that the reported errors in the HII measurements may not be purely Gaussian, perhaps due to a partial contamination by non-Gaussian systematic effects. The use of HII galaxies and HII regions as standard candles may be improved even further with a better handling of the systematics in these sources.

• 出版日期2018-3