摘要
A linear correlation has been proposed between the CO luminosity (L′ <sub>CO</sub> ) and the full width at half-maximum (FWHM) for high-redshift (z > 1) submillimetre galaxies. However, the controversy concerning the L′ <sub>CO</sub> -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′ <sub>CO</sub> -FWHM correlations for both low-redshift and high-redshift samples. A comparison of the low- and high-redshift L′ <sub>CO</sub> -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 wCDM with our samples, the derived values are w 0 = -1.02 ± 0.17, δ m0 = 0.30 ± 0.02 and H <sub>0</sub> =70.00± 0.60 km s <sup>-1</sup> , Mpc <sup>-1</sup> .