Method of determining cosmological parameter ranges with samples of candles with an intrinsic distribution  

作　　者：覃一平 张彬彬 董云明 张富文 李怀珍 贾兰伟 毛李胜 陆睿静 易庭丰 崔晓红 张志彬 

机构地区：[1]National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, China [2]Physics Department, Guangxi University, Nanning, Guangxi 530004, China [3]The Graduate School of the Chinese Academy of Sciences, Beijing 100049, China

出　　处：《Chinese Physics B》2006年第7期1645-1652,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China （Grant Nos 10273019 and 10463001） and State Key Development Program for Basic Research of China （Grant No G2000077602）.

摘　　要：In this paper, the effect of the intrinsic distribution of cosmological candles is investigated. We find that in the case of a narrow distribution the deviation of the observed modulus of sources from the expected central value can be estimated within a ceratin range. We thus introduce lower and upper limits of X^2, X^2min and X^2max to estimate cosmological parameters by applying the conventional minimizing X^2 method. We apply this method to a gammaray burst （GRB） sample as well as to a combined sample including this GRB sample and an SN Ia sample. Our analysis shows that： a） in the case of assuming an intrinsic distribution of candles of the GRB sample, the effect of the distribution is obvious and should not be neglected; b） taking into account this effect would lead to a poorer constraint of the cosmological parameter ranges. The analysis suggests that in the attempt of constraining the cosmological model with current GRB samples, the results tend to be worse than was previously anticipated if the mentioned intrinsic distribution does exist.In this paper, the effect of the intrinsic distribution of cosmological candles is investigated. We find that in the case of a narrow distribution the deviation of the observed modulus of sources from the expected central value can be estimated within a ceratin range. We thus introduce lower and upper limits of X^2, X^2min and X^2max to estimate cosmological parameters by applying the conventional minimizing X^2 method. We apply this method to a gammaray burst （GRB） sample as well as to a combined sample including this GRB sample and an SN Ia sample. Our analysis shows that： a） in the case of assuming an intrinsic distribution of candles of the GRB sample, the effect of the distribution is obvious and should not be neglected; b） taking into account this effect would lead to a poorer constraint of the cosmological parameter ranges. The analysis suggests that in the attempt of constraining the cosmological model with current GRB samples, the results tend to be worse than was previously anticipated if the mentioned intrinsic distribution does exist.

关 键 词：cosmological parameters observational cosmology distance scale 

分 类 号：P14[天文地球—天体物理]