CO luminosity–FWHM correlation of low- and high-redshift galaxies and its possible cosmological utilization. Issue 4 (10th January 2019)

• Record Type: Journal Article
• Authors: Wu, Yi-Han; Goto, Tomotsugu; Kilerci-Eser, Ece; Hashimoto, Tetsuya; Kim, Seong-Jin; Chiang, Chia-Ying; Huang, Ting-Chi
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 483:Issue 4(2019)
• Page Start: 5281
• Page End: 5290
• Publication Date: 2019-01-10
• Subjects: equation of state -- cosmological parameters -- dark energy -- distance scale -- cosmology: observations -- submillimetre: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty3392
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: A linear correlation has been proposed between the CO luminosity (${L}^{\prime }_{\rm {CO}}$ ) and the full width at half-maximum (FWHM) for high-redshift ($z$ > 1) submillimetre galaxies. However, the controversy concerning the${L}^{\prime }_{\rm {CO}}$ –FWHM correlation seems to have been caused by the use of heterogeneous samples (e.g. different transition lines) and/or data with large measurement uncertainties. In order to avoid the uncertainty caused by using different rotational transitions, in this work we make an extensive effort to select only CO( J = 1−0) data from the literature. We separate these wide-ranging redshift data into two samples: the low-redshift ($z$ < 1) and high-redshift ($z$ > 1) samples. The samples are corrected for lensing magnification factors if gravitational-lensing effects appeared in the observations. The correlation analysis shows that there exists significant${L}^{\prime }_{\rm {CO}}$ –FWHM correlations for both low-redshift and high-redshift samples. A comparison of the low- and high-redshift${L}^{\prime }_{\rm {CO}}$ –FWHM correlations does not show strong evolution with redshift. Assuming that there is no evolution, we can use this relation to determine the model-independent distances of high-redshift galaxies. We then constrain cosmological models with the calibrated high-redshift CO data and the sample of Type Ia supernovae in the Union 2.1 compilation. In the constraint for$w$ CDM with our samples, the derived values are$w$ 0 = −1.02 ± 0.17, Ωm0 = 0.30 ± 0.02 and${H}_{0}=70.00\pm {0.60}\, \, \rm {km\, s^{-1}\, Mpc^{-1}}$ .