论文标题
一颗星星，两颗星，还是两者？使用Illustristng模拟研究伽马射线爆发祖细胞的金属依赖性模型
One star, two stars, or both? Investigating metallicity-dependant models for Gamma-Ray Burst progenitors with the IllustrisTNG simulation
论文作者
论文摘要
长期伽马射线爆发（GRB）的速率已被确定为跨红移的恒星形成速率（SFR）的潜在代理，但是确切的关系取决于GRB祖细胞模型（单一对二进制）。单生折叠模型解释了对低金属性GRB祖细胞的偏好，但显然具有一些高金属性GRB宿主星系测量的张力。作为一种可能的解决方案，我们考虑了高金属性GRB宿主在其中形成GRB祖细胞的低金属区域的情况。为此，我们使用Illustristng宇宙学水动力学模拟来研究GRB宿主的内部金属性分布，从而实现了后处理不同的GRB形成模型。将预测（GRB速率，宿主金属性和恒星质量）与高度完整性GRB传统调查BAT6和浅滩进行了比较，以及一个高红移GRB-DLA金属度的样本，使我们能够计算其相对可能性。当忽略星系的内部金属性分布时，最合适的模型需要与Trenti，Perna＆Jimenez先前提出的金属无关的通道。但是，当考虑内部金属分布时，$ z_ {max} = 0.35Z_ \ odot $的基本金属偏置模型是最佳拟合。当前的数据不足以区分更详细的金属性偏差模型，例如大量二进制的金属依赖性与折叠质量更强的金属性偏置。在红移$ z> 2 $处的物体样本和直接测量的宿主恒星质量的直接测量将允许进一步限制长GRB的起源。
The rate of long-duration gamma ray bursts (GRBs) has been identified as a potential proxy for the star formation rate (SFR) across redshift, but the exact relationship depends on GRB progenitor models (single versus binary). The single-progenitor collapsar model accounts for the preference towards low-metallicity GRB progenitors, but is in apparent tension with some high-metallicity GRB host galaxy measurements. As a possible solution, we consider the scenario where high-metallicity GRB hosts harbour low metallicity regions in which GRB progenitors form. For this, we use the IllustrisTNG cosmological hydrodynamical simulation to investigate the internal metallicity distribution of GRB hosts, implementing in post-processing different GRB formation models. Predictions (GRB rate, host metallicities and stellar masses) are compared to the high-completeness GRB legacy surveys BAT6 and SHOALS and a sample of high-redshift GRB-DLA metallicities, allowing us to compute their relative likelihoods. When the internal metallicity distribution of galaxies is ignored, the best-fitting model requires a metallicity-independent channel, as previously proposed by Trenti, Perna & Jimenez. However, when the internal metallicity distribution is considered, a basic metallicity bias model with a cutoff at $Z_{max}=0.35Z_\odot$ is the best fitting one. Current data are insufficient to discriminate among more detailed metallicity bias models, such as weak metallicity dependence of massive binaries vs stronger metallicity bias of collapsars. An increased sample of objects, and direct measurements of host stellar masses at redshift $z>2$ would allow to further constrain the origin of long GRBs.
