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arXiv 1907.09772astro-ph.COastro-ph.HE
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用FRB和H(z)数据约束IGM中重子分数的演化

Constraining the Evolution of the Baryon Fraction in the IGM with FRB and H(z) data

Jun-Jie Wei, Zhengxiang Li, He Gao, Xue-Feng Wu

摘要:

通过对快速射电暴(FRB)观测获得的河外色散测量(DM)是探测星系际介质(IGM)和进行宇宙学研究的一个很好的工具。然而,来自IGM的DM贡献(${\rm DM_{IGM}}$)取决于IGM中重子质量的分数$f_{\rm IGM}$,这没有被适当地约束。由于$f_{\rm IGM}(z)$与哈勃参数$H(z)$和${\rm DM_{IGM}}(z)$在几何上相关,本文提出结合两个在相似红移范围内的FRB和$H(z)$的独立测量,提供了一种新的无宇宙学约束的方法来约束$f_{\rm IGM}(z)$的演化.在假设$f_{\rm IGM}$随红移以函数形式演化的前提下,我们预测,通过对FRB的$\sim3000$ ${\rm DM_{IGM}}(z)$和哈勃参数数据的$\sim50$ $H(z)$的综合分析,可以很好地推断出$f_{\rm IGM}(z)$的演化.虽然我们的方法的效率不如其他模型无关的方法,涉及的DM和光度距离的FRB的联合测量,我们的方法提供了一个新的模型无关的方式来约束$f_{\rm IGM}(z)$。

英文摘要:

Extragalactic dispersion measures (DMs) obtained from observations of fast radio bursts (FRBs) are an excellent tool for probing intergalactic medium (IGM) and for conducting cosmography. However, the DM contribution from the IGM (${\rm DM_{IGM}}$) depends on the fraction of baryon mass in the IGM, $f_{\rm IGM}$, which is not properly constrained. As $f_{\rm IGM}(z)$ is geometrically related to the Hubble parameter $H(z)$ and ${\rm DM_{IGM}}(z)$, here we propose that combining two independent measurements of FRBs and $H(z)$ in similar redshift ranges provides a novel and cosmology-free method to constrain the evolution of $f_{\rm IGM}(z)$. Under the assumption that $f_{\rm IGM}$ is evolving with redshift in a functional form, we forecast that the evolution of $f_{\rm IGM}(z)$ can be well inferred in a combined analysis of $\sim3000$ ${\rm DM_{IGM}}(z)$ derived from FRBs and $\sim50$ $H(z)$ derived from the Hubble parameter data. Though the efficiency of our method is not as good as that of the other model-independent method involving the joint measurements of DM and luminosity distance of FRBs, our method offers a new model-independent way to constrain $f_{\rm IGM}(z)$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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