Gamma-ray bursts in 1.8 < z < 5.6 suggest that the time variation of the dark energy is small
Gamma-ray bursts in 1.8 < z < 5.6 suggest that the time variation of the dark energy is small
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DOI：
10.1111/j.1745-3933.2008.00508.x
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发表时间：
2008-02
影响因子：
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通讯作者：
Y. Kodama;D. Yonetoku;T. Murakami;S. Tanabe;Ryo Tsutsui;Takashi Nakamura Kyoto University;K. University
中科院分区：
文献类型：
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作者：
Y. Kodama;D. Yonetoku;T. Murakami;S. Tanabe;Ryo Tsutsui;Takashi Nakamura Kyoto University;K. University
我们利用33个红移z < 1.62的事件，在不假设任何宇宙学模型的情况下，校准了伽马射线暴的峰值能量-峰值亮度关系（GRB;所谓的Yonetoku关系）。伽玛暴的光度距离是根据大量z < 1.755的Ia型超新星的光度距离估算的。这个校准的米德关系可以作为一个新的宇宙距离阶梯，迈向更高的红移。利用校正后的关系，我们确定了30个1.8 < z < 5.6的伽玛暴的光度距离，并在（Ωm，ΩΛ）平面上绘制了似然等高线。对于平坦宇宙，我们得到（Ωm，ΩΛ）=（0.37+0.14−0.11，0.63+0.11−0.14）。因为我们的方法不受圆度问题的影响，我们可以说我们在1.8 < z < 5.6的宇宙与z < 1.8时导出的所谓和谐宇宙学模型是相容的。这表明暗能量的时间变化很小或为零，直到z = 6。
We calibrated the peak energy–peak luminosity relation of gamma-ray bursts (GRBs; the so-called Yonetoku relation) using 33 events with redshift z < 1.62 without assuming any cosmological models. The luminosity distances to GRBs are estimated from those of large numbers of Type Ia supernovae with z < 1.755. This calibrated Yonetoku relation can be used as a new cosmic distance ladder towards higher redshifts. We determined the luminosity distances of 30 GRBs in 1.8 < z < 5.6 using the calibrated relation, and plotted the likelihood contour in the (Ωm, ΩΛ) plane. We obtained (Ωm, ΩΛ) = (0.37+0.14−0.11, 0.63+0.11−0.14) for a flat universe. Because our method is free from the circularity problem, we can say that our universe in 1.8 < z < 5.6 is compatible with the so-called concordance cosmological model derived for z < 1.8. This suggests that the time variation of the dark energy is small or zero up to z∼ 6.