Revisiting Metallicity of Long Duration Gamma-Ray Burst Host Galaxies: The Role of Chemical Inhomogeneity within Galaxies
Revisiting Metallicity of Long Duration Gamma-Ray Burst Host Galaxies: The Role of Chemical Inhomogeneity within Galaxies
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DOI：
10.1111/j.1365-2966.2011.19299.x
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发表时间：
2011-03
期刊：
影响因子：
--
通讯作者：
Y. Niino
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文献类型：
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作者：
Y. Niino
我们预测的金属丰度概率分布函数（PDF）的长伽玛射线暴（GRB）的宿主星系在低红移（$z \la 0.3$）时，GRB只发生在低金属丰度的环境，假设经验公式的星系属性。我们讨论了高金属丰度星系对低金属丰度伽玛暴宇宙速率的贡献，考虑了每个星系内金属丰度的内部分散。假设伽玛射线暴跟踪低金属丰度星星形成8.8美元，如果星系的金属丰度的内部分散在银河系中观察到的。我们的研究结果表明，低金属丰度的伽玛暴祖先的情况下，可以调和与最近发现的高金属丰度的伽玛暴宿主星系。我们还显示了可能的双峰性的主机金属丰度PDF，结果从单祖模型的伽玛暴。如果在未来的观察中发现，双峰性可能是限制GRB祖细胞性质的线索。
We predict the metallicity probability distribution function (PDF) of long gamma-ray burst (GRB) host galaxies at low-redshifts ($z \la 0.3$) when GRBs occur only in low-metallicity environment, assuming empirical formulations of galaxy properties. We discuss contribution of high-metallicity galaxies to the cosmic rate of low-metallicity GRBs, taking internal dispersion of metallicity within each galaxy into account. Assuming GRBs trace low-metallicity star formation $ 8.8$, if galaxies have internal dispersion of metallicity comparable to that observed in the Milky Way. Our results show that the low-metallicity scenario of GRB progenitors can be reconciled with the recent discoveries of the high-metallicity host galaxies of GRBs. We also show possible bimodality in the host metallicity PDF that results from the single progenitor model of GRBs. If found in future observation, the bimodality can be a clue to constrain the nature of GRB progenitors.