论文标题

从快速无线电爆发和超新星数据的IgM中对宇宙模型的限制无关的约束

Cosmological model-independent constraints on the baryon fraction in the IGM from fast radio bursts and supernovae data

论文作者

Lemos, Thais, Gonçalves, Rodrigo S., Carvalho, Joel C., Alcaniz, Jailson S.

论文摘要

快速无线电爆发(FRB)是毫秒持续的无线电瞬变,观察到的色散度量($ dm $)大于预期的银河系贡献,这表明此类事件具有外层状的起源。尽管已经提出了一些模型来解释脉冲的物理,但FRBS发射背后的机制仍然未知。从具有已知宿主星系的FRB数据中,红移是直接测量的,可以与$ dm $的估计结合使用,以限制宇宙学参数,例如Baryon数字密度和哈勃常数。然而,对男性层间培养基($ f_ {igm} $)中重质质量的不良知识及其与宇宙学参数的退化性对FRB的宇宙学应用施加了限制。在这项工作中,我们提出了一种独立于宇宙模型的方法,以确定$ f_ {igm} $的演变,该方法将最新的FRB观测值与局部宿主星系和当前的超新星数据相结合。我们考虑恒定且与时间有关的$ f_ {igm} $参数化,并通过贝叶斯模型选择分析显示,关于$ f_ {igm} $的时间进步的结论性答案很大程度上取决于$ dm $ $ $ $ $ $ $ $ $ $ $ $ $的波动,这是由于宇宙电子密度($δ$)的空间变化。特别是,我们的分析表明,由于考虑了较大的$δ$的值,因此证据从强度(有利于$ f_ {igm} $的增长的$ f_ {igm} $)变化。

Fast Radio Bursts (FRBs) are millisecond-duration radio transients with an observed dispersion measure ($DM$) greater than the expected Milky Way contribution, which suggests that such events are of extragalactic origin. Although some models have been proposed to explain the physics of the pulse, the mechanism behind the FRBs emission is still unknown. From FRBs data with known host galaxies, the redshift is directly measured and can be combined with estimates of the $DM$ to constrain the cosmological parameters, such as the baryon number density and the Hubble constant. However, the poor knowledge of the fraction of baryonic mass in the intergalactic medium ($f_{IGM}$) and its degeneracy with the cosmological parameters impose limits on the cosmological application of FRBs. In this work we present a cosmological model-independent method to determine the evolution of $f_{IGM}$ combining the latest FRBs observations with localized host galaxy and current supernovae data. We consider constant and time-dependent $f_{IGM}$ parameterizations and show, through a Bayesian model selection analysis, that a conclusive answer about the time-evolution of $f_{IGM}$ depend strongly on the $DM$ fluctuations due to the spatial variation in cosmic electron density ($δ$). In particular, our analysis show that the evidence varies from strong (in favor of a growing evolution of $f_{IGM}$ with redshift) to inconclusive, as larger values of $δ$ are considered.

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