Constraining the Cosmological Parameters and Transition Redshift with Gamma-Ray Bursts and Supernovae
Constraining the Cosmological Parameters and Transition Redshift with Gamma-Ray Bursts and Supernovae
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DOI：
10.1111/j.1365-2966.2006.10108.x
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发表时间：
2005-12
影响因子：
4.8
通讯作者：
Fayin Wang;Z. Dai
中科院分区：
文献类型：
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作者：
Fayin Wang;Z. Dai
梁和张最近提出了一种利用伽马射线暴（GRB）测量宇宙学的新方法。在该方法中，仅使用可观测量，包括 νF ν 光谱的静止帧峰值能量 (E' p )、GRB 的各向同性能量 (E γ,iso ) 和静止帧中光学余辉光曲线的中断时间 (t' b )。通过考虑这种方法，我们限制了宇宙学参数和宇宙从减速阶段膨胀到加速阶段时的红移。我们将五个最近检测到的GRB添加到样本中，并针对Ω M = 0.28和H 0 = 71.0km s -1 Mpc -1 的平坦宇宙得出E γ,iso /10 52 erg = (0.93 ± 0.25) (E' p /100 keV) 1.91±0.32 (t'b/1d) -0.93±0.38 。这种关系与爆发周围的介质密度以及爆炸能量到伽马射线能量的转换效率无关。我们将 E γ,iso (E' p , t' b ) 关系视为标准蜡烛，并发现 0.05 < Ω M < 0.48 和 Ω Λ < 1.15（在 la 置信水平）。在具有宇宙学常数的平坦宇宙中，我们在 la 置信水平下获得 0.25 < Ω M < 0.46 和 0.54 < Ω Λ < 0.78。跃迁红移为 z T = 0.69 +0.11 -0.12 。将 20 个伽玛暴与 157 个 Ia 型超新星（SNe Ia）结合起来，我们发现平坦宇宙的 Ω M = 0.29 ± 0.03，过渡红移为 z T = 0.61 +0.06 -0.05 ，该值略大于单独考虑 SNe Ia 时发现的值。特别是，我们还讨论了几种参数化状态方程 w(z) 的暗能量模型，并详细研究了宇宙学参数的约束。
A new method of measuring cosmology with gamma-ray bursts (GRBs) has been proposed by Liang and Zhang recently. In this method, only observable quantities including the rest-frame peak energy of the νF ν spectrum (E' p ), the isotropic energy of GRB (E γ,iso ) and the break time of the optical afterglow light curves in the rest frame (t' b ) are used. By considering this method, we constrain the cosmological parameters and the redshift at which the Universe expanded from the deceleration to acceleration phase. We add five recently detected GRBs to the sample and derive E γ,iso /10 52 erg = (0.93 ± 0.25) (E' p /100 keV) 1.91±0.32 (t'b/1d) -0.93±0.38 for a flat universe with Ω M = 0.28 and H 0 = 71.0km s -1 Mpc -1 . This relation is independent of the medium density around bursts and the efficiency of conversion of the explosion energy to gamma-ray energy. We consider the E γ,iso (E' p , t' b ) relationship as a standard candle and find 0.05 < Ω M < 0.48 and Ω Λ < 1.15 (at the la confidence level). In a flat universe with the cosmological constant, we obtain 0.25 < Ω M < 0.46 and 0.54 < Ω Λ < 0.78 at the la confidence level. The transition redshift is z T = 0.69 +0.11 -0.12 . Combining 20 GRBs with 157 Type Ia supernovae (SNe Ia), we find Ω M = 0.29 ± 0.03 for a flat universe and the transition redshift is z T = 0.61 +0.06 -0.05 , which is slightly larger than the value found by considering SNe Ia alone. In particular, we also discuss several dark-energy models in which the equation of state w(z) is parametrized, and investigate constraints on the cosmological parameters in detail.