Impact of the turnover in the high-z galaxy luminosity function on the 21-cm signal during Cosmic Dawn and Epoch of Reionization

Abstract

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 $\beta$ and a UV conversion factor $l_{\mathrm{UV}}$. According to our fit of 68\% confidence level, the high-redshift star formation in haloes smaller than $M_t=1.82_{-1.08}^{+2.86}\times 10^{10}{\mathrm{M}}_{\odot }$ is found to be dampened. The turnover magnitude $\gtrsim -13.99-2.45$, correspondingly the halo mass $\lesssim (4.57+20.03)\times 10^9{\mathrm{M}}_{\odot }$. We find that the absorption trough in the global 21-cm signal is sensitive to our SFE model parameters. Together with ($\beta$, $l_{\mathrm{UV}}$) = ($2.17_{-1.72}^{+2.42}$, $9.33_{-0.42}^{+0.43}\mathrm{erg}\mathrm{yr}{\mathrm{s}}^{-1}{\mathrm{M}}_{\odot }^{-1})$, the trough locates at $\sim$ $134_{-17}^{+10}$ $\mathrm{MHz}$ with an amplitude of $\sim$ $-237_{+7}^{-6}$ $\mathrm{mK}$, 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 $\sim 4\%$ and shifts towards smaller scales from $0.88h\mathrm{Mp}{\mathrm{c}}^{-1}$ to $0.91h\mathrm{Mp}{\mathrm{c}}^{-1}$. According to our calculation, such impact is distinguishable with the forthcoming Square Kilometre Array.

11 pages, 5 figures; Accepted by MNRAS

References in corpus (14)

• Cosmic Star Formation History
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• Model-independent evidence in favor of an end to reionization by z~6
• The Global 21 Centimeter Background from High Redshifts
• Line Emitting Galaxies Beyond a Redshift of 7: An Improved Method for Estimating the Evolving Neutrality of the Intergalactic Medium
• New observations of z~7 galaxies: evidence for a patchy reionization
• Hubble Frontier Fields First Complete Cluster Data: Faint Galaxies at $z\sim 5-10$ for UV Luminosity Functions and Cosmic Reionization
• Accelerated Evolution of Ly$\alpha$ Luminosity Function at $\text{z}\gtrsim 7$ Revealed by the Subaru Ultra-Deep Survey for Ly$\alpha$ Emitters at $\text{z}=7.3$
• The Global 21-cm Signal in the Context of the High-z Galaxy Luminosity Function
• BIGHORNS - Broadband Instrument for Global HydrOgen ReioNisation Signal
• The Evolution of the UV Luminosity Function from z ~ 0.75 to z ~ 2.5 using HST ERS WFC3/UVIS Observations
• Decoding the X-ray Properties of Pre-Reionization Era Sources
• Ultra-faint high-redshift galaxies in the Frontier Fields
• Direct Parameter Inference from Global EoR Signal with Bayesian Statistics

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• POLAR -- I: linking the 21-cm signal from the epoch of reionization to galaxy formation
• Constraints on the galaxy formation models during epoch of reionization with high redshift observations