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arXiv 1003.5755astro-ph.CO
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用宇宙学方法校正GRB光度关系

Calibration of GRB Luminosity Relations with Cosmography

He Gao, Nan Liang, Zong-Hong Zhu

摘要:

为了利用伽马射线暴(GRB)以一种与宇宙学无关的方式探测宇宙学,提出了一种直接从Ia型超新星的哈勃图中插值得到GRB光度距离,然后标定高红移GRB关系的新方法。在本文中,遵循插值方法的基本假设,即在相同的红移的对象应该有相同的光度距离,我们提出了另一种方法来校准伽玛暴光度关系与宇宙学拟合直接从超新星Ia数据。在宇宙学中,有一个著名的拟合公式,它可以用观测数据拟合出的宇宙学参数来反映哈勃光度距离与红移之间的关系。利用Ia超新星并集的宇宙学拟合结果,用$z\leq1.4$上的GRB样品标定了5个GRB关系式,并将上述标定关系式推广到高红移处,推导出了$1.4< z \leq 6.6$上GRB的距离模。最后,利用高红移γ射线暴观测、宇宙微波背景辐射(CMB)观测和重子声振荡(BAO)观测,对Chevallier-Polarski-Linder(CPL)模型、Jassal-Bagla-Padmanabhan(JBP)模型和Alam模型的暗能量参数化模型进行了约束,发现$Λ$ CDM模型在1- $σ$置信区间内与当前观测结果一致.

英文摘要:

For the use of Gamma-Ray Bursts (GRBs) to probe cosmology in a cosmology-independent way, a new method has been proposed to obtain luminosity distances of GRBs by interpolating directly from the Hubble diagram of SNe Ia, and then calibrating GRB relations at high redshift. In this paper, following the basic assumption in the interpolation method that objects at the same redshift should have the same luminosity distance, we propose another approach to calibrate GRB luminosity relations with cosmographic fitting directly from SN Ia data. In cosmography, there is a well-known fitting formula which can reflect the Hubble relation between luminosity distance and redshift with cosmographic parameters which can be fitted from observation data. Using the Cosmographic fitting results from the Union set of SNe Ia, we calibrate five GRB relations using GRB sample at $z\leq1.4$ and deduce distance moduli of GRBs at $1.4< z \leq 6.6$ by generalizing above calibrated relations at high redshift. Finally, we constrain the dark energy parameterization models of the Chevallier-Polarski-Linder (CPL) model, the Jassal-Bagla-Padmanabhan (JBP) model and the Alam model with GRB data at high redshift, as well as with the Cosmic Microwave Background radiation (CMB) and the baryonic acoustic oscillation (BAO) observations, and we find the $Λ$CDM model is consistent with the current data in 1-$σ$ confidence region.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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