Constraining Cosmological Parameters Based on Relative Galaxy Ages
Constraining Cosmological Parameters Based on Relative Galaxy Ages
复制标题
DOI：
10.1086/340549
复制
发表时间：
2001-06
期刊：
影响因子：
--
通讯作者：
R. Jimenez;A. Loeb
中科院分区：
文献类型：
--
作者：
R. Jimenez;A. Loeb
我们建议使用相对星系年龄作为约束宇宙学参数的一种手段。通过测量两个被动演化星系团在不同红移下的年龄差异，可以确定红移对宇宙时间的导数dz/dt。在高红移z ~ 1-2时，这个测量将限制暗能量的状态方程，而在低红移z = 0.2时，它将确定哈勃常数H 0。此外，我们表明，d2 z/dt 2直接跟踪状态方程的暗能量，因此，在低红移测量这个量可以用来约束它。选定的星系需要被动地演变的时间远远长于他们的年龄差。
We propose to use relative galaxy ages as a means of constraining cosmological parameters. By measuring the age difference between two ensembles of passively evolving galaxies at somewhat different redshifts, one could determine the derivative of redshift with respect to cosmic time, dz/dt. At high redshifts, z ~ 1-2, this measurement would constrain the equation of state of the dark energy, while at low redshifts, z ≲ 0.2, it would determine the Hubble constant, H0. Furthermore, we show that d2z/dt2 directly tracks the equation of state of the dark energy; thus, measurements of this quantity at low redshifts can be used to constrain it. The selected galaxies need to be passively evolving on a time much longer than their age difference.