Long Gamma-Ray Burst Rate at Very High Redshift
Long Gamma-Ray Burst Rate at Very High Redshift
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DOI：
10.3847/1538-4357/ab2188
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发表时间：
2019-01
期刊：
影响因子：
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通讯作者：
T. Kinugawa;Y. Harikane;K. Asano
中科院分区：
文献类型：
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作者：
T. Kinugawa;Y. Harikane;K. Asano
未来的高红移长伽马射线暴(GRB)观测任务，如揭开黑暗时代任务的高z伽马射线暴和瞬变高能天空和早期宇宙探测器，将为我们宇宙中的恒星形成历史提供线索。本文以高红移(z>；8)伽玛暴为研究对象，考虑群I星、群II星和群III星作为伽玛暴的前身，计算了未来观测对长伽玛暴的探测率。对于群I和群II的恒星形成率(SFR)，我们采用了基于晕质量函数和从宇宙学模拟得到的暗物质吸积率的高红移SFR的最新模型。结果表明，随着红移的增加，种群I和II的GRB率急剧下降。这将使我们能够探测到红移非常高的不同类型的伽玛暴--种群III伽玛暴。如果10%或更多的人口III恒星作为超长伽玛暴死亡，未来的任务将在一年内探测到这样的伽玛暴，尽管它们的通量很低。通过双星合并产生的巨型致密星系III恒星有望产生更明亮的伽玛暴。在我们的常规情况下，这种发光的伽玛暴的探测率是3-20年−1(z>；8)。这些未来的观测有助于揭示恒星群III的恒星形成历史。
Future missions for long gamma-ray burst (GRB) observations at high redshift, such as the High-z Gamma-ray bursts for Unraveling the Dark Ages Mission and the Transient High-Energy Sky and Early Universe Surveyor, will provide clues to the star formation history in our universe. In this paper focusing on high-redshift (z > 8) GRBs, we calculate the detection rate of long GRBs by future observations, considering both Population I and II stars and Population III stars as GRB progenitors. For the Population I and II star formation rate (SFR), we adopt an up-to-date model of a high-redshift SFR based on the halo mass function and the dark matter accretion rate obtained from cosmological simulations. We show that the Population I and II GRB rate steeply decreases with redshift. This would rather enable us to detect the different type of GRBs, Population III GRBs, at very high redshift. If 10% or more Population III stars die as an ultra-long GRB, the future missions would detect such GRBs in one year in spite of their low fluence. More luminous GRBs are expected from massive compact Population III stars produced via the binary merger. In our conventional case, the detection rate of such luminous GRBs is 3–20 yr−1 (z > 8). Those future observations contribute to revealing the Population III star formation history.