Dependence on the environment of the abundance function of light-cone simulation dark matter haloes

Aims. We study the dependence of the halo abundance function (AF) on different environments in a whole-sky ΛCDM light-cone halo catalogue extending to z ~ 0.65, using a simple and well-defined halo isolation criterion. Methods. The isolation status of each individual dark matter halo is determined by the distance to its nearest neighbour, which defines the maximum spherical region devoid of halos above a threshold mass around it (although the true size of such region may be much larger since it is not necessarily spherical). A versatile double power-law Schechter function is used to fit the dark matter halo AF, and its derived parameters are studied as a function of halo isolation status. Results. (a) Our function fits the halo abundances for all halo isolation statuses extremely well, while the well-established theoretical mass functions, integrated over the volume of the light-cone, provide an adequate but poorer fit than our phenomenological model. (b) As expected, and in agreement with other studies based on snap-shot simulations, we find significant differences of the halo abundance function as a function of halo isolation, indicating different rates of halo formation. The slope of the power law and the characteristic mass of the Schechter-like fitting function decrease with isolation, a result consistent with the formation of less massive haloes in lower density regions. (c) We find an unexpected upturn of the characteristic mass of the most isolated haloes of our sample. This upturn originates and characterises only the higher redshift regime (z ≳ 0.45), which probably implies a significant and recent evolution of the isolation status of the most isolated and most massive haloes.

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HMFcalc: An online tool for calculating dark matter halo mass functions

Astronomy and Computing ◽

10.1016/j.ascom.2013.11.001 ◽

2013 ◽

Vol 3-4 ◽

pp. 23-34 ◽

Cited By ~ 145

Author(s):

S.G. Murray ◽

C. Power ◽

A.S.G. Robotham

Keyword(s):

Dark Matter ◽

Dark Matter Halo ◽

Online Tool ◽

Mass Functions

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Deriving the Nonlinear Cosmological Power Spectrum and Bispectrum from Analytic Dark Matter Halo Profiles and Mass Functions

The Astrophysical Journal ◽

10.1086/317146 ◽

2000 ◽

Vol 543 (2) ◽

pp. 503-513 ◽

Cited By ~ 255

Author(s):

Chung‐Pei Ma ◽

J. N. Fry

Keyword(s):

Dark Matter ◽

Power Spectrum ◽

Dark Matter Halo ◽

Mass Functions

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The stellar-to-halo mass relation over the past 12 Gyr

Astronomy and Astrophysics ◽

10.1051/0004-6361/201936329 ◽

2020 ◽

Vol 634 ◽

pp. A135 ◽

Cited By ~ 6

Author(s):

G. Girelli ◽

L. Pozzetti ◽

M. Bolzonella ◽

C. Giocoli ◽

F. Marulli ◽

...

Keyword(s):

Dark Matter ◽

Star Formation ◽

Galaxy Formation ◽

Stellar Mass ◽

Dark Matter Halo ◽

Mass Relation ◽

Massive Galaxies ◽

Halo Masses ◽

Formation Efficiency ◽

Mass Functions

Aims. Understanding the link between the galaxy properties and the dark matter halos they reside in and their coevolution is a powerful tool for constraining the processes related to galaxy formation. In particular, the stellar-to-halo mass relation (SHMR) and its evolution throughout the history of the Universe provides insights on galaxy formation models and allows us to assign galaxy masses to halos in N-body dark matter simulations. To address these questions, we determine the SHMR throughout the entire cosmic history from z ∼ 4 to the present. Methods. We used a statistical approach to link the observed galaxy stellar mass functions on the COSMOS field to dark matter halo mass functions up to z ∼ 4 from the ΛCDM DUSTGRAIN-pathfinder simulation, which is complete for Mh > 1012.5 M⊙, and extended this to lower masses with a theoretical parameterization. We propose an empirical model to describe the evolution of the SHMR as a function of redshift (either in the presence or absence of a scatter in stellar mass at fixed halo mass), and compare the results with several literature works and semianalytic models of galaxy formation. We also tested the reliability of our results by comparing them to observed galaxy stellar mass functions and to clustering measurements. Results. We derive the SHMR from z = 0 to z = 4, and model its empirical evolution with redshift. We find that M*/Mh is always lower than ∼0.05 and depends both on redshift and halo mass, with a bell shape that peaks at Mh ∼ 1012 M⊙. Assuming a constant cosmic baryon fraction, we calculate the star-formation efficiency of galaxies and find that it is generally low; its peak increases with cosmic time from ∼30% at z ∼ 4 to ∼35% at z ∼ 0. Moreover, the star formation efficiency increases for increasing redshifts at masses higher than the peak of the SHMR, while the trend is reversed for masses lower than the peak. This indicates that massive galaxies (i.e., galaxies hosted at halo masses higher than the SHMR peak) formed with a higher efficiency at higher redshifts (i.e., downsizing effect) and vice versa for low-mass halos. We find a large scatter in results from semianalytic models, with a difference of up to a factor ∼8 compared to our results, and an opposite evolutionary trend at high halo masses. By comparing our results with those in the literature, we find that while at z ∼ 0 all results agree well (within a factor of ∼3), at z > 0 many differences emerge. This suggests that observational and theoretical work still needs to be done. Our results agree well (within ∼10%) with observed stellar mass functions (out to z = 4) and observed clustering of massive galaxies (M* > 1011 M⊙ from z ∼ 0.5 to z ∼ 1.1) in the two-halo regime.

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The normalization and slope of the dark matter (sub-)halo mass function on sub-galactic scales

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa341 ◽

2020 ◽

Vol 493 (1) ◽

pp. 1268-1276

Author(s):

Andrew J Benson

Keyword(s):

Dark Matter ◽

Gravitational Lensing ◽

Cold Dark Matter ◽

Mass Range ◽

Mass Function ◽

Matter Content ◽

Dark Matter Halo ◽

Halo Masses ◽

Near Future ◽

Mass Functions

ABSTRACT Simulations of cold dark matter make robust predictions about the slope and normalization of the dark matter halo and subhalo mass functions on small scales. Recent observational advances utilizing strong gravitational lensing have demonstrated the ability of this technique to place constraints on these quantities on subgalactic scales corresponding to dark matter halo masses of 106–$10^9\, \mathrm{M}_\odot$. On these scales the physics of baryons, which make up around 17 per cent of the matter content of the Universe but which are not included in pure dark matter N-body simulations, are expected to affect the growth of structure and the collapse of dark matter haloes. In this work, we develop a semi-analytic model to predict the amplitude and slope of the dark matter halo and subhalo mass functions on subgalactic scales in the presence of baryons. We find that the halo mass function is suppressed by up to 25 per cent, and the slope is modified, ranging from −1.916 to −1.868 in this mass range. These results are consistent with current measurements, but differ sufficiently from the expectations for a dark matter only universe that it may be testable in the near future.

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Testing dark matter halo properties using self-similarity

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3435 ◽

2020 ◽

Author(s):

M Leroy ◽

L Garrison ◽

D Eisenstein ◽

M Joyce ◽

S Maleubre

Keyword(s):

Dark Matter ◽

Particle Number ◽

Percent Level ◽

Mass Function ◽

Dark Matter Halo ◽

Self Similarity ◽

Good Convergence ◽

Scale Free ◽

Point Correlation ◽

Mass Functions

Abstract We use self-similarity in N-body simulations of scale-free models to test for resolution dependence in the mass function and two-point correlation functions of dark matter halos. We use 10243 particle simulations performed with Abacus, and compare results obtained with two halo finders: friends-of-friends (fof) and Rockstar. The fof mass functions show a systematic deviation from self-similarity which is explained by resolution dependence of the fof mass assignment previously reported in the literature. Weak evidence for convergence is observed only starting from halos of several thousand particles, and mass functions are overestimated by at least as much as $20-25\%$ for halos of 50 particles. The mass function of the default Rockstar halo catalog (with bound virial spherical overdensity mass), on the other hand, shows good convergence from of order 50 to 100 particles per halo, with no detectable evidence at the few percent level of any systematic dependence for larger particle number. Tests show that the mass unbinding procedure in Rockstar is the key factor in obtaining this much improved resolution. Applying the same analysis to the halo-halo two point correlation function, we find again strong evidence for convergence only for Rockstar halos, at separations sufficiently large so that halos do not overlap. At these separations we can exclude dependence on resolution at the $5-10\%$ level once halos have of order 50 to 100 particles. At smaller separations results are not converged even at significantly larger particle number, and bigger simulations would be required to establish the resolution required for convergence.

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Clustering of dark halos on the lightcone

Symposium - International Astronomical Union ◽

10.1017/s0074180900207791 ◽

2003 ◽

Vol 208 ◽

pp. 467-468

Author(s):

Naoki Yoshida ◽

Takashi Hamana ◽

Yasushi Suto ◽

August Evrard

Keyword(s):

Dark Matter ◽

Phenomenological Model ◽

Correlation Functions ◽

Light Cone ◽

Theoretical Models ◽

Dark Matter Halos ◽

Model Predictions ◽

Astrophysical Objects ◽

Point Correlation ◽

Good Agreement

We present a phenomenological model to predict the clustering of dark matter halos on the light-cone. The model is constructed by combining several existing theoretical models. We test our model against the Hubble Volume N-body simulation and examine its validity. A good agreement is found in two-point correlation functions of dark matter halos between our model predictions and measurements from the simulation. The model is quite general and thus can be applied to a wider range of astrophysical objects, such as galaxies and quasars.

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Equilibrium initial data for luminous matter on top of a BEC dark matter halo

Journal of Physics Conference Series ◽

10.1088/1742-6596/1010/1/012004 ◽

2018 ◽

Vol 1010 ◽

pp. 012004

Author(s):

J. A. González ◽

F. S. Guzmán

Keyword(s):

Dark Matter ◽

Initial Data ◽

Dark Matter Halo ◽

Luminous Matter

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Two-component galaxy models with a central BH – II. The ellipsoidal case

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3338 ◽

2020 ◽

Vol 500 (1) ◽

pp. 1054-1070

Author(s):

Luca Ciotti ◽

Antonio Mancino ◽

Silvia Pellegrini ◽

Azadeh Ziaee Lorzad

Keyword(s):

Dark Matter ◽

Stellar Dynamics ◽

Azimuthal Velocity ◽

Dark Matter Halo ◽

Gas Flows ◽

Total Density ◽

Density Distributions ◽

Stellar Component ◽

Two Component ◽

Analytical Formulae

ABSTRACT Recently, two-component spherical galaxy models have been presented, where the stellar profile is described by a Jaffe law, and the total density by another Jaffe law, or by an r−3 law at large radii. We extend these two families to their ellipsoidal axisymmetric counterparts: the JJe and J3e models. The total and stellar density distributions can have different flattenings and scale lengths, and the dark matter halo is defined by difference. First, the analytical conditions required to have a nowhere negative dark matter halo density are derived. The Jeans equations for the stellar component are then solved analytically, in the limit of small flattenings, also in the presence of a central BH. The azimuthal velocity dispersion anisotropy is described by the Satoh k-decomposition. Finally, we present the analytical formulae for velocity fields near the centre and at large radii, together with the various terms entering the virial theorem. The JJe and J3e models can be useful in a number of theoretical applications, e.g. to explore the role of the various parameters (flattening, relative scale lengths, mass ratios, rotational support) in determining the behaviour of the stellar kinematical fields before performing more time-expensive integrations with specific galaxy models, to test codes of stellar dynamics and in numerical simulations of gas flows in galaxies.

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Brightest cluster galaxies: the centre can(not?) hold

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3286 ◽

2020 ◽

Vol 500 (1) ◽

pp. 310-318

Author(s):

Roberto De Propris ◽

Michael J West ◽

Felipe Andrade-Santos ◽

Cinthia Ragone-Figueroa ◽

Elena Rasia ◽

...

Keyword(s):

Dark Matter ◽

Local Environment ◽

Major Axis ◽

Theoretical Models ◽

Dark Matter Halo ◽

Gas Distribution ◽

X Ray ◽

Cluster Galaxies ◽

Peculiar Velocities ◽

Brightest Cluster Galaxies

ABSTRACT We explore the persistence of the alignment of brightest cluster galaxies (BCGs) with their local environment. We find that a significant fraction of BCGs do not coincide with the centroid of the X-ray gas distribution and/or show peculiar velocities (they are not at rest with respect to the cluster mean). Despite this, we find that BCGs are generally aligned with the cluster mass distribution even when they have significant offsets from the X-ray centre and significant peculiar velocities. The large offsets are not consistent with simple theoretical models. To account for these observations BCGs must undergo mergers preferentially along their major axis, the main infall direction. Such BCGs may be oscillating within the cluster potential after having been displaced by mergers or collisions, or the dark matter halo itself may not yet be relaxed.

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