分类： 天文学 >> 天文学 提交时间： 2023-02-19
Shiming Gu
Marc-Antoine Dor
Ludovic van Waerbeke
Marika Asgari
Alexander Mead
Tilman Tröster
Ziang Yan
摘要： Semi-analytical computation of the matter power spectrum often relies on the halo mass function (HMF) as a key component. In this paper, we explore how certain variations of the HMF affect the modelling of the matter power spectra and quantify the impact on the structure growth parameter $S_8 = \sigma_8\sqrt{\Omega_\mathrm{m}/0.3}$. We use the weak gravitational lensing 2-point correlation functions from both Kilo Degree Survey (KiDS-1000) and Dark Energy Survey (DES-y3) to constrain the HMF parameters, which are sensitive to dark matter properties, structure formation, and baryonic feedback. When assuming the Planck cosmology, the canonical HMF parameters are rejected at more than $2\sigma$ level for both KiDS and DES, where reconstructed HMF from these posteriors give a $48.8\%^{+8.3\%}_{-9.4\%}$ lower for KiDS-1000 and a $29.5\%^{+8.5\%}_{-8.5\%}$ lower for DES-y3 in terms of total halo mass larger than $M_\mathrm{Halo} > 10^{14} M_\odot$ compared to a canonical HMF model. In addition, a Planck-like $S_8$ is also preferred if massive haloes were to have a $\sim 20\%$ lower abundance compared to a canonical halo mass function. Under one of these alternative HMFs, we found $S_8 \sim 0.826_{-0.019}^{+0.021}$ for KiDS-1000 and $0.851_{-0.021}^{+0.020}$ for DES-y3. Our work suggests that varying the halo abundance provides an alternative to varying the matter power spectrum when exploring possible solutions to the $S_8$ tension. By comparing the posteriors of both cosmological and HMF parameters between two different surveys (KiDS-1000 and DES-y3), we are also testing the self-consistency of the cosmological interpretation at a level that has corresponding particle and/or astrophysical interpretations.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Ziang Yan
Ludovic van Waerbeke
Tilman Tröster
Angus H. Wright
David Alonso
Marika Asgari
Maciej Bilicki
Thomas Erben
Shiming Gu
Catherine Heymans
Hendrik Hildebrandt
Gary Hinshaw
Nick Koukoufilippas
Arun Kannawadi
Konrad Kuijken
Alexander Mead
HuanYuan Shan
摘要： We constrain the redshift dependence of gas pressure bias $\left\langle b_{y} P_{\mathrm{e}}\right\rangle$ (bias-weighted average electron pressure), which characterises the thermodynamics of intergalactic gas, through a combination of cross-correlations between galaxy positions and the thermal Sunyaev-Zeldovich (tSZ) effect, as well as galaxy positions and the gravitational lensing of the cosmic microwave background (CMB). The galaxy sample is from the fourth data release of the Kilo-Degree Survey (KiDS). The tSZ $y$ map and the CMB lensing map are from the {\textit{Planck}} 2015 and 2018 data releases, respectively. The measurements are performed in five redshift bins with $z\lesssim1$. With these measurements, combining galaxy-tSZ and galaxy-CMB lensing cross-correlations allows us to break the degeneracy between galaxy bias and gas pressure bias, and hence constrain them simultaneously. In all redshift bins, the best-fit values of $\bpe$ are at a level of $\sim 0.3\, \mathrm{meV/cm^3}$ and increase slightly with redshift. The galaxy bias is consistent with unity in all the redshift bins. Our results are not sensitive to the non-linear details of the cross-correlation, which are smoothed out by the {\textit{Planck}} beam. Our measurements are in agreement with previous measurements as well as with theoretical predictions. We also show that our conclusions are not changed when CMB lensing is replaced by galaxy lensing, which shows the consistency of the two lensing signals despite their radically different redshift ranges. This study demonstrates the feasibility of using CMB lensing to calibrate the galaxy distribution such that the galaxy distribution can be used as a mass proxy without relying on the precise knowledge of the matter distribution.
分类： 天文学 >> 天文学 提交时间： 2023-02-19
Ziang Yan
Ludovic van Waerbeke
Angus H. Wright
Maciej Bilicki
Shiming Gu
Hendrik Hildebrandt
Abhishek S. Maniyar
Tilman Tröster
摘要： In this work, we probe the star formation history of the Universe using tomographic cross-correlation between the cosmic infrared background (CIB) and galaxy samples. The galaxy samples are from the Kilo-Degree Survey (KiDS), while the CIB maps are made from \planck\, sky maps. We measure the cross-correlation in harmonic space with a significance of 43$\sigma$. We model the cross-correlation with a halo model, which links CIB anisotropies to star formation rates (SFR) and galaxy abundance. We assume that SFR has a lognormal dependence on halo mass, while galaxy abundance follows the halo occupation distribution (HOD) model. The cross-correlations give a best-fit maximum star formation efficiency of $\eta_{\mathrm{max}}= 0.41^{+0.09}_{-0.14}$ at a halo mass $\log_{10}(M_{\mathrm{peak}}/M_{\odot})= {12.14\pm 0.36}$. The derived star formation rate density (SFRD) is well constrained up to $z\sim 1.5$. The constraining power at high redshift is mainly limited by the KiDS survey depth. A combination with external SFRD measurements from previous studies gives $\log_{10}(M_{\mathrm{peak}}/M_{\odot})=12.42^{+0.35}_{-0.19}$. This tightens the SFRD constraint up to $z=4$, yielding a peak SFRD of $0.09_{-0.004}^{+0.003}\,M_{\odot} \mathrm { year }^{-1} \mathrm{Mpc}^{-3}$ at $z=1.74^{+0.06}_{-0.02}$, corresponding to a lookback time of $10.05^{+0.12}_{-0.03}$ Gyr. Both constraints are consistent, and the derived SFRD agrees with previous studies and simulations. Additionally, we estimate the galaxy bias $b$ of KiDS galaxies from the constrained HOD parameters and yield an increasing bias from $b=1.1_{-0.31}^{+0.17}$ at $z=0$ to $b=1.96_{-0.64}^{+0.18}$ at $z=1.5$. Finally, we provide a forecast for future galaxy surveys and conclude that, due to their considerable depth, future surveys will yield a much tighter constraint on the evolution of the SFRD.
点击量
待评议
点击量
下载量
评论
