CAN GAMMA-RAY BURST JETS BREAK OUT THE FIRST STARS?
CAN GAMMA-RAY BURST JETS BREAK OUT THE FIRST STARS?
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DOI：
10.1088/0004-637x/726/2/107
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发表时间：
2010-09
期刊：
影响因子：
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通讯作者：
Y. Suwa;K. Ioka
中科院分区：
文献类型：
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作者：
Y. Suwa;K. Ioka
我们展示了一个相对论伽马射线暴（GRB）射流可以潜在地穿透一个非常大质量的第一代恒星（星族III，以下简称Pop III）的包络，通过使用恒星密度剖面来估计喷流亮度（通过吸积）和它的穿透能力。即使Pop III恒星有一个没有质量损失的超巨型氢包层，由于包层本身长期存在的强大吸积，喷射爆发也是可能的。虽然Pop III GRB估计是高能的（γ,iso ~ 1055 erg），但超巨星包层将初始明亮阶段隐藏在cocoon成分中，导致GRB具有长持续时间~ 1000(1 + z) s和普通各向同性光度~ 1052 erg s−1（红移z ~ 20处为~ 10−9 erg cm−2 s−1）。由于中心温度较低，Pop III型伽马射线暴的中微子湮灭不有效，而磁机制是可行的。我们还推导了适用于各种祖模型的突破条件的分析估计。GRB的亮度和持续时间对核心和包层质量非常敏感，这为高红移暗时代结束时的第一批发光物体提供了可能的探测。
We show that a relativistic gamma-ray burst (GRB) jet can potentially pierce the envelope of a very massive first generation star (Population III, hereafter Pop III) by using the stellar density profile to estimate both the jet luminosity (via accretion) and its penetrability. The jet breakout is possible even if the Pop III star has a supergiant hydrogen envelope without mass loss, thanks to the long-lived powerful accretion of the envelope itself. While the Pop III GRB is estimated to be energetic (Eγ,iso ∼ 1055 erg), the supergiant envelope hides the initial bright phase in the cocoon component, leading to a GRB with a long duration ∼1000(1 + z) s and an ordinary isotropic luminosity ∼1052 erg s−1 (∼10−9 erg cm−2 s−1 at redshift z ∼ 20). The neutrino annihilation is not effective for Pop III GRBs because of a low central temperature, while the magnetic mechanism is viable. We also derive analytic estimates of the breakout conditions, which are applicable to various progenitor models. The GRB luminosity and duration are found to be very sensitive to the core and envelope mass, providing possible probes of the first luminous objects at the end of the high-redshift dark ages.