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

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.

scholarly journals Survey of gravitationally-lensed objects in HSC imaging (SuGOHI)

2019 ◽  
Vol 630 ◽  
pp. A71 ◽  
Author(s):  
Alessandro Sonnenfeld ◽  
Anton T. Jaelani ◽  
James Chan ◽  
Anupreeta More ◽  
Sherry H. Suyu ◽  
...  
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Mass Function ◽  
Initial Mass Function ◽  
Dark Matter Halo ◽  
Open Problems ◽  
Massive Galaxies ◽  
Spatially Resolved ◽  
Stellar Masses ◽  
The Imf

Context. The determination of the stellar initial mass function (IMF) of massive galaxies is one of the open problems in cosmology. Strong gravitational lensing is one of the few methods that allow us to constrain the IMF outside of the Local Group. Aims. The goal of this study is to statistically constrain the distribution in the IMF mismatch parameter, defined as the ratio between the true stellar mass of a galaxy and that inferred assuming a reference IMF, of massive galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS) constant mass (CMASS) sample. Methods. We took 23 strong lenses drawn from the CMASS sample, measured their Einstein radii and stellar masses using multi-band photometry from the Hyper Suprime-Cam survey, then fitted a model distribution for the IMF mismatch parameter and dark matter halo mass to the whole sample. We used a prior on halo mass from weak lensing measurements and accounted for strong lensing selection effects in our model. Results. Assuming a Navarro Frenk and White density profile for the dark matter distribution, we infer a value μIMF = −0.04 ± 0.11 for the average base-10 logarithm of the IMF mismatch parameter, defined with respect to a Chabrier IMF. A Salpeter IMF is in tension with our measurements. Conclusions. Our results are consistent with a scenario in which the region of massive galaxies where the IMF normalisation is significantly heavier than that of the Milky Way is much smaller than the scales 5 − 10 kpc probed by the Einstein radius of the lenses in our sample, as recent spatially-resolved studies of the IMF in massive galaxies suggest.

Effects of non-vanishing dark matter pressure in the Milky Way Galaxy

2021 ◽  
Vol 508 (1) ◽  
pp. 1543-1554
Author(s):  
K Boshkayev ◽  
T Konysbayev ◽  
E Kurmanov ◽  
O Luongo ◽  
D Malafarina ◽  
...  
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Gravitational Lensing ◽  
Matter Content ◽  
Dark Matter Halo ◽  
Matter Distribution ◽  
Milky Way Galaxy ◽  
The Galaxy ◽  
Dark Matter Distribution ◽  
Inner Parts

ABSTRACT We consider the possibility that the Milky Way’s dark matter halo possesses a non-vanishing equation of state. Consequently, we evaluate the contribution due to the speed of sound, assuming that the dark matter content of the galaxy behaves like a fluid with pressure. In particular, we model the dark matter distribution via an exponential sphere profile in the galactic core, and inner parts of the galaxy whereas we compare the exponential sphere with three widely used profiles for the halo, i.e. the Einasto, Burkert and Isothermal profile. For the galactic core, we also compare the effects due to a dark matter distribution without black hole with the case of a supermassive black hole in vacuum and show that present observations are unable to distinguish them. Finally we investigate the expected experimental signature provided by gravitational lensing due to the presence of dark matter in the core.

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

2020 ◽  
Vol 634 ◽  
pp. A135 ◽  
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.

scholarly journals THE MASS FUNCTION OF DARK MATTER HALOES IN A COSMOLOGICAL MODEL WITH A RUNNING PRIMORDIAL POWER SPECTRUM

2005 ◽  
Vol 14 (08) ◽  
pp. 1305-1312
Author(s):  
TONG-JIE ZHANG ◽  
HONG LIANG ◽  
WEN-ZHONG LIU ◽  
BAO-QUAN WANG
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Mass Function ◽  
Small Mass ◽  
Cluster Of Galaxies ◽  
Primordial Power Spectrum ◽  
Power Spectral ◽  
Halo Masses ◽  
Mass Functions ◽  
The Universe

We present the first study on the mass functions of Jenkins et al. (J01) and an estimate of their corresponding largest virialized dark halos in the Universe for a variety of dark-energy cosmological models with a running spectral index. Compared with the PL–CDM model, the RSI–CDM model can raise the mass abundance of dark halos for small mass halos at lower redshifts, but it is not apparent on scales of massive mass halos. Particularly, this discrepancy increases largely with the decrease of redshift, and the RSI–CDM model can suppress the mass abundance on any scale of halo masses at higher redshift. As for the largest mass of virialized halos, the spatially flat ΛCDM models give more massive mass of virialized objects than other models for both of PL–CDM and RSI–CDM power spectral indexs, and the RSI–CDM model can enhance the mass of largest virialized halos for all of models considered in this paper. So we probably distinguish the PL–CDM and RSI–CDM models by the largest virialized halos in the future survey of cluster of galaxies.

scholarly journals Testing dark matter halo properties using self-similarity

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.

scholarly journals LARGE SCALE STRUCTURE BY GLOBAL MONOPOLES AND COLD DARK MATTER

1992 ◽  
Vol 07 (10) ◽  
pp. 903-910 ◽  
Author(s):  
LEANDROS PERIVOLAROPOULOS
Keyword(s):  
Dark Matter ◽  
Cosmological Model ◽  
Gravitational Wave ◽  
Large Scale ◽  
Cold Dark Matter ◽  
Mass Range ◽  
Large Scale Structure ◽  
Mass Function ◽  
Global Monopoles ◽  
Good Agreement

A cosmological model in which the primordial perturbations are provided by global monopoles and in which the dark matter is cold has several interesting features. The model is normalized by choosing its single parameter within the bounds obtained from gravitational wave constraints and by demanding coherent velocity flows of about 600 km/sec on scales of 50h-1 Mpc . Using this normalization, the model predicts the existence of dominant structures with mass 2×1016M⊙ on a scale 35h-1 Mpc , i.e., larger than the horizon at t ep . The magnitude of the predicted mass function in the galactic mass range is in good agreement with the observed Schechter function.

scholarly journals Galaxy Halo Masses from Weak Gravitational Lensing

2014 ◽  
Vol 10 (S311) ◽  
pp. 86-95 ◽  
Author(s):  
Rachel Mandelbaum
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Dark Matter Halo ◽  
Dark Matter Halos ◽  
Weak Gravitational Lensing ◽  
Galaxy Halo ◽  
Halo Masses ◽  
The Masses ◽  
The Relationship ◽  
Intrinsic Scatter

AbstractIn this review, I discuss the use of galaxy-galaxy weak lensing measurements to study the masses of dark matter halos in which galaxies reside. After summarizing how weak gravitational lensing measurements can be interpreted in terms of halo mass, I review measurements that were used to derive the relationship between optical galaxy mass tracers, such as stellar mass or luminosity, and dark matter halo mass. Measurements of galaxy-galaxy lensing from the past decade have led to increasingly tight constraints on the connection between dark matter halo mass and optical mass tracers, including both the mean relationships between these quantities and the intrinsic scatter between them. I also review some of the factors that can complicate analysis, such as the choice of modeling procedure, and choices made when dividing up samples of lens galaxies.

scholarly journals Probing dark matter structure down to 107 solar masses: flux ratio statistics in gravitational lenses with line-of-sight haloes

2019 ◽  
Vol 487 (4) ◽  
pp. 5721-5738 ◽  
Author(s):  
Daniel Gilman ◽  
Simon Birrer ◽  
Tommaso Treu ◽  
Anna Nierenberg ◽  
Andrew Benson
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
High Redshift ◽  
Flux Ratio ◽  
Mass Function ◽  
Line Of Sight ◽  
Gravitational Lenses ◽  
Modelling Framework ◽  
Powerful Means ◽  
Mass Functions

Abstract Strong lensing provides a powerful means of investigating the nature of dark matter as it probes dark matter structure on sub-galactic scales. We present an extension of a forward modelling framework that uses flux ratios from quadruply imaged quasars (quads) to measure the shape and amplitude of the halo mass function, including line-of-sight (LOS) haloes and main deflector subhaloes. We apply this machinery to 50 mock lenses – roughly the number of known quads – with warm dark matter (WDM) mass functions exhibiting free-streaming cut-offs parametrized by the half-mode mass mhm. Assuming cold dark matter (CDM), we forecast bounds on mhm and the corresponding thermal relic particle masses over a range of tidal destruction severity, assuming a particular WDM mass function and mass–concentration relation. With significant tidal destruction, at 2σ we constrain $m_{\rm {hm}}\lt 10^{7.9} \left(10^{8.4}\right) \, \mathrm{M}_{\odot }$, or a 4.4 (3.1) keV thermal relic, with image flux uncertainties from measurements and lens modelling of $2{{\ \rm per\ cent}} \left(6{{\ \rm per\ cent}}\right)$. With less severe tidal destruction we constrain $m_{\rm {hm}}\lt 10^{7} \left(10^{7.4}\right) \, \mathrm{M}_{\odot }$, or an 8.2 (6.2) keV thermal relic. If dark matter is warm, with $m_{\rm {hm}} = 10^{7.7} \, \mathrm{M}_{\odot }$ (5.1 keV), we would favour WDM with $m_{\rm {hm}} \gt 10^{7.7} \, \mathrm{M}_{\odot }$ over CDM with relative likelihoods of 22:1 and 8:1 with flux uncertainties of $2{{\ \rm per\ cent}}$ and $6{{\ \rm per\ cent}}$, respectively. These bounds improve over those obtained by modelling only main deflector subhaloes because LOS objects produce additional flux perturbations, especially for high-redshift systems. These results indicate that ∼50 quads can conclusively differentiate between WDM and CDM.

scholarly journals Luminous and dark matter in early-type lens galaxies

2009 ◽  
Vol 5 (H15) ◽  
pp. 70-70
Author(s):  
C. Grillo
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Gravitational Lensing ◽  
Elliptical Galaxy ◽  
Matter Content ◽  
Effective Radius ◽  
Dark Matter Halo ◽  
Early Type ◽  
The Galaxy ◽  
Lens Galaxies

In the past few years gravitational lensing has allowed astrophysicists to make great progress in the understanding of the internal structure of early-type galaxies. By taking advantage of accurate photometric and spectroscopic measurements, the luminous and dark matter content of lens galaxies can in principle be disentangled (e.g., Grillo et al. 2008, 2009). SDSS J1538+5817 is an extraordinary strong lensing system composed of an elliptical galaxy and two equally-distant sources located, respectively, at redshifts 0.143 and 0.531 (Grillo et al., submitted to ApJ). The sources are lensed into two and four images with an almost complete Einstein ring, covering a rather large region on the lens plane. By using HST/ACS and WFPC2 imaging and NOT/ALFOSC spectroscopy, we have investigated the lens total mass distribution within one effective radius. Then, we have fitted the SDSS multicolor photometry of the galaxy with composite stellar population models to obtain its luminous mass. By combining lensing and photometric measurements, we have estimated the lens mass in terms of luminous and dark matter components and studied the global properties of the dark matter halo. The exceptional lensing configuration of this system has allowed us to conclude that the galaxy dark matter density distribution is shallower and more diffused than the luminous one and the former starts exceeding the latter at a distance of approximately 1.5 times the effective radius. Extending these results to a larger number of lenses would help us to decipher the processes that rule galaxy formation and evolution in the LCDM scenario.

scholarly journals Dark matter-deficient dwarf galaxies form via tidal stripping of dark matter in interactions with massive companions

2021 ◽  
Vol 502 (2) ◽  
pp. 1785-1796
Author(s):  
R A Jackson ◽  
S Kaviraj ◽  
G Martin ◽  
J E G Devriendt ◽  
A Slyz ◽  
...  
Keyword(s):  
Dark Matter ◽  
Galaxy Evolution ◽  
Cold Dark Matter ◽  
Dwarf Galaxies ◽  
Stellar Mass ◽  
Matter Content ◽  
Mass Relation ◽  
Potential Wells ◽  
Tidal Interactions ◽  
New Interactions

ABSTRACT In the standard ΛCDM (Lambda cold dark matter) paradigm, dwarf galaxies are expected to be dark matter-rich, as baryonic feedback is thought to quickly drive gas out of their shallow potential wells and quench star formation at early epochs. Recent observations of local dwarfs with extremely low dark matter content appear to contradict this picture, potentially bringing the validity of the standard model into question. We use NewHorizon, a high-resolution cosmological simulation, to demonstrate that sustained stripping of dark matter, in tidal interactions between a massive galaxy and a dwarf satellite, naturally produces dwarfs that are dark matter-deficient, even though their initial dark matter fractions are normal. The process of dark matter stripping is responsible for the large scatter in the halo-to-stellar mass relation in the dwarf regime. The degree of stripping is driven by the closeness of the orbit of the dwarf around its massive companion and, in extreme cases, produces dwarfs with halo-to-stellar mass ratios as low as unity, consistent with the findings of recent observational studies. ∼30 per cent of dwarfs show some deviation from normal dark matter fractions due to dark matter stripping, with 10 per cent showing high levels of dark matter deficiency (Mhalo/M⋆ < 10). Given their close orbits, a significant fraction of dark matter-deficient dwarfs merge with their massive companions (e.g. ∼70 per cent merge over time-scales of ∼3.5 Gyr), with the dark matter-deficient population being constantly replenished by new interactions between dwarfs and massive companions. The creation of these galaxies is therefore a natural by-product of galaxy evolution and their existence is not in tension with the standard paradigm.

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