We use a statistical approach to determine the relationship between the stellar masses of galaxies and the masses of the dark matter halos in which they reside. We obtain a parameterized stellar-to-halo mass (SHM) relation by populating halos and subhalos in an N-body simulation with galaxies and requiring that the observed stellar mass function be reproduced. We find good agreement with constraints from galaxy-galaxy lensing and predictions of semi-analytic models. Using this mapping, and the positions of the halos and subhalos obtained from the simulation, we find that our model predictions for the galaxy two-point correlation function (CF) as a function of stellar mass are in excellent agreement with the observed clustering properties in the SDSS at z=0. We show that the clustering data do not provide additional strong constraints on the SHM function and conclude that our model can therefore predict clustering as a function of stellar mass. We compute the conditional mass function, which yields the average number of galaxies with stellar masses in the range [m, m+dm] that reside in a halo of mass M. We study the redshift dependence of the SHM relation and show that, for low mass halos, the SHM ratio is lower at higher redshift. The derived SHM relation is used to predict the stellar mass dependent galaxy CF and bias at high redshift. Our model predicts that not only are massive galaxies more biased than low mass ones at all redshifts, but the bias increases more rapidly with increasing redshift for massive galaxies than for low mass ones. We present convenient fitting functions for the SHM relation as a function of redshift, the conditional mass function, and the bias as a function of stellar mass and redshift.
The mapping of galaxy clustering from real space to redshift space introduces the anisotropic property to the measured galaxy density power spectrum in redshift space, known as the redshift space distortion (RSD) effect. The mapping formula is intrinsically non-linear, which is complicated by the higher order polynomials due to indefinite orders of cross correlations between density and velocity fields, and the Finger--of--God (FoG) effect due to the randomness of the galaxy peculiar velocity field. In previous works, we have verified the robustness of advanced TNS mapping formula in our hybri…
We study the effect of large-scale tidal fields on internal halo properties using a set of N-body simulations. We measure significant cross-correlations between large-scale tidal fields and several non-scalar halo properties: shapes, velocity dispersion, and angular momentum. Selection effects that couple to these non-scalar halo properties can produce anisotropic clustering even in real-space. We investigate the size of this effect and show that it can produce a non-zero quadrupole similar in size to the one generated by linear redshift-space distortions (RSD). Finally, we investigate the clu…
Gravitational redshifts and other relativistic effects are beginning to be studied in the context of galaxy clustering. Distortions consistent with those expected in General Relativity have been measured in galaxy cluster redshift profiles by Wojtak et al. and others and in the the cross-correlation function of galaxy populations by Alam et al. On scales below ~20 Mpc/$h$ simulations have shown that gravitational redshift dominates over other effects. However, this signal is related to the shape and depth of gravitational potentials, and therefore the matter density in galaxies and galaxy clus…
In this paper we investigate how the halo mass function evolves with redshift, based on a suite of very large (with N_p = 3072^3 - 6000^3 particles) cosmological N-body simulations. Our halo catalogue data spans a redshift range of z = 0-30, allowing us to probe the mass function from the dark ages to the present. We utilise both the Friends-of-Friends (FOF) and Spherical Overdensity (SO) halofinding methods to directly compare the mass function derived using these commonly used halo definitions. The mass function from SO haloes exhibits a clear evolution with redshift, especially during the r…
The emission in the hyperfine structure 21 cm line of atomic hydrogen arising in the halos with masses $\sim10^6-10^{10}$ M$_\odot$ from the Dark Ages in the models with Warm Dark Matter (WDM) is analysed. The halos are assumed to be formed from Gaussian density peaks of cosmological density perturbations at $10\lesssim z\lesssim50$. Semi-analytical modelling of the formation of individual spherical halos in multi-component models shows that gas in them has the kinetic temperature in the range of $60-800$ K under adiabatic compression of the collapsing halo, and the temperature of each halo de…
CUSP is a powerful formalism that recovers, from first principles and with no free parameter, all the macroscopic properties of dark matter haloes found in cosmological N-body simulations and unveils the origin of their characteristic features. Since it is not restricted by the limitations of simulations, it covers the whole mass and redshift ranges. In the present Paper we use CUSP to calculate the mass-scale relations holding for halo density profiles fitted to the usual NFW and Einasto functions in the most relevant cosmologies and for the most usual mass definitions. We clarify the origin …
An accurate theoretical template of the redshift-space galaxy power spectrum, if applicable out to nonlinear scales, enables us to extract more stringent and robust constraints on cosmological parameters from the measured galaxy clustering. In this work, we develop a simulation-based template, so-called emulator, for the redshift-space power spectrum of dark matter halos. Using the redshift-space halo power spectra measured from the Dark Quest $N$-body simulation suite that covers 101 flat-geometry $w$CDM cosmologies around the Planck $Λ$CDM model, we feed these data into a feed-forward neural…
Reconstruction of halo power spectrum from redshift-space galaxy distribution: cylinder-grouping method and halo exclusion effect
星系巡天观测中红移空间畸变(RSD)测量到的奇特速度场为研究大尺度结构的生长提供了独特的途径。然而,系统的影响时,包括卫星星系的聚类分析。由于卫星星系倾向于居住在具有更大晕偏差的大质量晕中,因此包含物增强了集群能力。此外,维里运动的卫星星系的非线性RSD效应导致了显着的抑制集群的权力。我们发展了一种新的方法来恢复红移空间功率谱的晕从观测到的星系分布,通过最大限度地减少污染的卫星星系。我们研究的圆柱分组方法(CGM)有效地将卫星星系从星系样本中排除。然而,我们发现,这种技术产生明显的各向异性在重建的晕分布在所有规模模仿RSD。在小尺度上,明显的各向异性聚类是由CGM使用的各向异性圆柱体内的晕排除引起的。在大尺度上,将沿视线排列的大尺度结构中的不同晕错误识别为同一CGM组,通过它们与CGM晕的互相关引起明显的各向异性聚类。我们构建了一个经验模型的CGM晕功率谱,其中包括使用CGM窗口函数在小尺度以及线性物质功率谱乘以一个简单的各向异性函数在大尺度上导出的校正项。我们将这个模型应用到z=0.5的模拟星系表中,设计成类似于SDSS-III BOSS CMASS星系,发现我们的模型可以预测宿主晕的四极和四极功率谱,直到k<0.5 h/Mpc,误差在5%以内。
The ecology of dark matter haloes I: The rates and types of halo interactions
合并和飞越等相互作用在塑造星系形态方面发挥着重要作用。使用Horizon Run 4宇宙学N体模拟,我们研究了晕相互作用的频率和类型,以及它们的红移演化作为由大尺度密度,对分离,质量比和目标晕质量定义的环境的函数。大多数相互作用发生在大尺度的密度差$δ\approx 20$,无论红移,对应于集团和相对密集的部分的细丝。然而,相互作用靶标的分数在$δ\approx 1000$处最大。我们提供了一个新的经验拟合形式的相互作用率作为晕质量,大尺度密度和红移的函数。从质量比和相对距离的分布来看,存在两种相互作用模式,这意味着相互作用的两种不同的物理起源。卫星目标在深入宿主晕的过程中失去质量。这两种趋势的相对重要性强烈地依赖于大尺度密度、目标质量和红移。
Galaxy clusters are luminous tracers of the most massive dark matter haloes in the Universe. To use them as a cosmological probe, a detailed description of the properties of dark matter haloes is required. We characterize how the dynamical state of haloes impacts the halo mass function at the high-mass end. We used the dark matter-only MultiDark suite of simulations and the high-mass objects M > 2.7e13 M/h therein. We measured mean relations of concentration, offset, and spin as a function of halo mass and redshift. We investigated the distributions around the mean relations. We measured the h…
An Improved Fit for Linear Halo Bias at High Redshift
University of Texas at Austin(德克萨斯大学奥斯汀分校);Cosmic Frontier Center(宇宙前沿中心);Texas Center for Cosmology & Astroparticle Physics(德克萨斯宇宙学与高能物理中心);Space Telescope Science Institute(太空望远镜科学研究所)
Ecology of dark matter haloes -II. Effects of interactions on the alignment of halo pairs
我们使用Horizon Run 4宇宙学N体模拟来研究远距离和近距离相互作用对目标晕与其邻居的形状、自旋和轨道对齐的影响,以及它们对局部密度环境和邻居分离的依赖性。相互作用的目标具有比所有目标明显更低的自旋和更高的球度和扁率。相互作用的电子对最初具有反平行的自旋,但随着时间的推移,自旋发展成平行排列。邻居倾向于在目标的旋转平面内演化,并且在长晕的主轴方向上。此外,相互作用优先是径向的,而具有非径向轨道的电子对优先是非径向的。对准信号在高质量和紧密分离时更强,并且与大尺度密度无关。正的对齐信号被发现在红移高达4,并增加减少红移。此外,轨道在低红移时趋于倾斜,而在高红移(z = 4)时没有发现对齐。
A redshift-independent theoretical halo mass function validated with Uchuu simulations
Instituto de Astrofisica de Andalucia (CSIC)(安达卢西亚天体物理研究所);Instituto de Astrofisica de Canarias(加那利天体物理研究所);Facultad de Fisica, Universidad de La Laguna(拉帕尔马大学物理学院);Digital Transformation Enhancement Council, Chiba University(千叶大学数字化转型促进委员会);Department of Astronomy, University of Virginia(弗吉尼亚大学天文学系)
The concentrations of dark matter haloes provide crucial information about their internal structure and how it depends on mass and redshift -- the so-called concentration-mass-redshift relation, denoted $c(M,z)$. We present here an extensive study of the cosmology-dependence of $c(M,z)$ that is based on a suite of 72 gravity-only, full N-body simulations in which the following cosmological parameters were varied: $σ_{8}$, $Ω_{\mathrm{M}}$, $Ω_{\mathrm{b}}$, $n_{\mathrm{s}}$, $h$, $M_ν$, $w_{0}$ and $w_{\mathrm{a}}$. We characterize the impact of these parameters on concentrations for different…
We study the halo mass function and inner halo structure at high redshifts ($z\geq5$) for a suite of simulations within the structure formation ETHOS framework. Scenarios such as cold dark matter (CDM), thermal warm dark matter (WDM), and dark acoustic oscillations (DAO) of various strengths are contained in ETHOS with just two parameters $h_{\rm peak}$ and $k_{\rm peak}$, the amplitude and scale of the first DAO peak. The Extended Press-Schechter (EPS) formalism with a smooth-$k$ filter is able to predict the cut-off in the halo mass function created by the suppression of small scale power in…
We introduce the Ultramarine simulation, an extremely large $N$-body simulation of the structure formation and evolution to redshift 5.5 at which cosmic reionization was just completed. The simulation evolves 2.1 trillion particles within a $512~h^{-1}$Mpc cube and has an unprecedented mass and force resolution for large volume simulations of this kind, $5.6\times 10^6 h^{-1}$M$_\odot$ and $1.2~h^{-1}$kpc, respectively. We present some basic statistical results of the simulation, including the halo mass function, halo bias parameter as well as halo mass-concentration relation at high redshifts…
We have studied the galaxy-group cross-correlations in redshift space for the Galaxy And Mass Assembly (GAMA) Survey. We use a set of mock GAMA galaxy and group catalogues to develop and test a novel 'halo streaming' model for redshift-space distortions. This treats 2-halo correlations via the streaming model, plus an empirical 1-halo term derived from the mocks, allowing accurate modelling into the nonlinear regime. In order to probe the robustness of the growth rate inferred from redshift-space distortions, we divide galaxies by colour, and divide groups according to their total stellar mass…
We study the ability of perturbative models with effective field theory contributions and infra-red resummation to model the redshift space clustering of biased tracers in models where the linear power spectrum has "features" -- either imprinted during inflation or induced by non-standard expansion histories. We show that both Eulerian and Lagrangian perturbation theory are capable of reproducing the Fourier space two-point functions of halos up to the non-linear scale from a suite of $4096^3$ particle N-body simulations. This is the first demonstration that perturbative models can accurately …