论文标题
在宇宙黎明和电离时期，高Z星系光度函数中的营业额对21厘米信号的影响
Impact of the turnover in the high-z galaxy luminosity function on the 21-cm signal during Cosmic Dawn and Epoch of Reionization
论文作者
论文摘要
高Z星系光度函数（LF）的微弱末端的形状为早期的恒星形成和电离物理学在宇宙黎明和电离时期的过程中提供了信息。直到最近，基于强力重力镜头簇深度调查，哈勃边境领域（HFF）发现紫外线（UV）LF的潜在营业额为z $ \ sim $ 6。在本文中，我们分析了极度微弱的星系的贡献，其幅度大于LF中的失误幅度对宇宙电离的贡献。我们将HFF的测量方法应用于被抑制的星形形成效率模型，包括三个免费参数：HALO质量阈值$ M_T $，曲率参数$β$和UV转换因子$ L _ {\ rm UV} $。根据我们的68 \％置信度的拟合度，光环中的高红移星形成小于$ m_t = 1.82^{+2.86} _ { - 1.08} \ times10^{10} \ rm m _ {\ odot} $。失误级$ \ rm \ gtrsim -13.99-2.45 $，相应地，halo smos $ \ sillesim（4.57+20.03）\ times10^{9} \ rm m _ {\ odot} $。我们发现全局21-CM信号中的吸收槽对我们的SFE模型参数敏感。与（$β$，$ l _ {\ rm uv} $）=（$ 2.17^{+2.42} _ { - 1.72} $，$ 9.33^{+0.43} _ { - 0.42} \ 0.42} \ rm〜erg〜 yr〜 yr〜 yr〜s^s^$ 1} $ 1} $ 1}位于$ \ sim $ $ 134^{+10} _ { - 17} $ $ \ rm MHz $，振幅为$ \ sim $ $ -237^{ - 6} _ {+7} $ \ 7} $ \ $ \ rm Mk $，与（106 \ rm MHz，-212 \ rmMMMMMMM MM MK）相比此外，我们发现微弱星系的恒星形成也对21厘米的功率谱也有影响。最佳拟合峰值功率降低了$ \ sim4 \％$，并从$ 0.88 h \ rm mpc^{ - 1} $转移到$ 0.91 h \ rm mpc^{ - 1} $。根据我们的计算，即即将到来的平方公里阵列可以区分这种影响。
The shape of the faint-end of the high-z galaxy luminosity function (LF) informs early star formation and reionization physics during the Cosmic Dawn and Epoch of Reionization. Until recently, based on the strong gravitational lensing cluster deep surveys, the Hubble Frontier Fields (HFF) has found a potential turnover in the ultraviolet (UV) LF at z$\sim$6. In this paper, we analyze the contribution of extremely faint galaxies with the magnitude larger than the turnover magnitude in LF to cosmic reionization. We apply the measurement from HFF to our suppressed star formation efficiency model, including three free parameters: halo mass threshold $M_t$, curvature parameter $β$ and a UV conversion factor $l_{\rm UV}$. According to our fit of 68\% confidence level, the high-redshift star formation in haloes smaller than $ M_t=1.82^{+2.86}_{-1.08}\times10^{10} \rm M_{\odot}$ is found to be dampened. The turnover magnitude $\rm \gtrsim -13.99-2.45$, correspondingly the halo mass $\lesssim(4.57+20.03)\times10^{9} \rm M_{\odot}$. We find that the absorption trough in the global 21-cm signal is sensitive to our SFE model parameters. Together with ($β$, $l_{\rm UV}$) = ($2.17^{+2.42}_{-1.72}$, $9.33^{+0.43}_{-0.42} \rm ~erg~yr ~s^{-1}M_{\odot}^{-1})$, the trough locates at $\sim$ $134^{+10}_{-17}$ $\rm MHz$ with an amplitude of $\sim$ $-237^{-6}_{+7}$ $\rm mK$, compared to (106\rm MHz, -212\rm mK) in the absence of turnover. Besides, we find that the star formation of faint galaxies has also an impact on the 21-cm power spectra. The best fitting peak power decreases by $\sim4\%$ and shifts towards smaller scales from $0.88 h \rm Mpc^{-1}$ to $0.91 h \rm Mpc^{-1}$. According to our calculation, such impact is distinguishable with the forthcoming Square Kilometre Array.
