supported by the National Natural Science Foundation of China (No. 11073007);the Guangzhou technological project (No. 11C62010685);Guangxi Natural Science Foundation (2012jjAA10090)
We make use of the recent large sample of 17 042 Mg Ⅱ absorption systems from Quider et al. to analyze the evolution of the redshift number density. Regardless of the strength of the absorption line, we find that the...
Supported by the National Natural Science Foundation of China(11073007);Guangzhou Technological Project(11C62010685);Guangxi Natural Science Foundation(2012jjAA10090)