scholarly journals Inference of the cold dark matter substructure mass function at z = 0.2 using strong gravitational lenses

2014 ◽  
Vol 442 (3) ◽  
pp. 2017-2035 ◽  
Author(s):  
S. Vegetti ◽  
L. V. E. Koopmans ◽  
M. W. Auger ◽  
T. Treu ◽  
A. S. Bolton
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Mass Function ◽  
Gravitational Lenses

scholarly journals Warm dark matter chills out: constraints on the halo mass function and the free-streaming length of dark matter with eight quadruple-image strong gravitational lenses

2019 ◽  
Vol 491 (4) ◽  
pp. 6077-6101 ◽  
Author(s):  
Daniel Gilman ◽  
Simon Birrer ◽  
Anna Nierenberg ◽  
Tommaso Treu ◽  
Xiaolong Du ◽  
...  
Keyword(s):  
Dark Matter ◽  
Mass Fraction ◽  
Mass Concentration ◽  
Cold Dark Matter ◽  
Finite Size ◽  
Mass Function ◽  
Line Of Sight ◽  
Gravitational Lenses ◽  
Likelihood Ratios ◽  
Mass Profile

ABSTRACT The free-streaming length of dark matter depends on fundamental dark matter physics, and determines the abundance and concentration of dark matter haloes on sub-galactic scales. Using the image positions and flux ratios from eight quadruply imaged quasars, we constrain the free-streaming length of dark matter and the amplitude of the subhalo mass function (SHMF). We model both main deflector subhaloes and haloes along the line of sight, and account for warm dark matter free-streaming effects on the mass function and mass–concentration relation. By calibrating the scaling of the SHMF with host halo mass and redshift using a suite of simulated haloes, we infer a global normalization for the SHMF. We account for finite-size background sources, and marginalize over the mass profile of the main deflector. Parametrizing dark matter free-streaming through the half-mode mass mhm, we constrain the thermal relic particle mass mDM corresponding to mhm. At $95 \, {\rm per\, cent}$ CI: mhm < 107.8 M⊙ ($m_{\rm {DM}} \gt 5.2 \ \rm {keV}$). We disfavour $m_{\rm {DM}} = 4.0 \,\rm {keV}$ and $m_{\rm {DM}} = 3.0 \,\rm {keV}$ with likelihood ratios of 7:1 and 30:1, respectively, relative to the peak of the posterior distribution. Assuming cold dark matter, we constrain the projected mass in substructure between 106 and 109 M⊙ near lensed images. At $68 \, {\rm per\, cent}$ CI, we infer $2.0{-}6.1 \times 10^{7}\, {{\rm M}_{\odot }}\,\rm {kpc^{-2}}$, corresponding to mean projected mass fraction $\bar{f}_{\rm {sub}} = 0.035_{-0.017}^{+0.021}$. At $95 \, {\rm per\, cent}$ CI, we obtain a lower bound on the projected mass of $0.6 \times 10^{7} \,{{\rm M}_{\odot }}\,\rm {kpc^{-2}}$, corresponding to $\bar{f}_{\rm {sub}} \gt 0.005$. These results agree with the predictions of cold dark matter.

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 Halo concentration strengthens dark matter constraints in galaxy-galaxy strong lensing analyses

2021 ◽  
Author(s):  
Nicola C Amorisco ◽  
James Nightingale ◽  
Qiuhan He ◽  
Aristeidis Amvrosiadis ◽  
Xiaoyue Cao ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Large Population ◽  
Dark Matter Particle ◽  
Mass Function ◽  
Gravitational Lenses ◽  
High Concentration ◽  
Expected Number ◽  
Order Of Magnitude ◽  
Low Mass

Abstract A defining prediction of the cold dark matter (CDM) cosmological model is the existence of a very large population of low-mass haloes. This population is absent in models in which the dark matter particle is warm (WDM). These alternatives can, in principle, be distinguished observationally because halos along the line-of-sight can perturb galaxy-galaxy strong gravitational lenses. Furthermore, the WDM particle mass could be deduced because the cut-off in their halo mass function depends on the mass of the particle. We systematically explore the detectability of low-mass haloes in WDM models by simulating and fitting mock lensed images. Contrary to previous studies, we find that halos are harder to detect when they are either behind or in front of the lens. Furthermore, we find that the perturbing effect of haloes increases with their concentration: detectable haloes are systematically high-concentration haloes, and accounting for the scatter in the mass-concentration relation boosts the expected number of detections by as much as an order of magnitude. Haloes have lower concentration for lower particle masses and this further suppresses the number of detectable haloes beyond the reduction arising from the lower halo abundances alone. Taking these effects into account can make lensing constraints on the value of the mass function cut-off at least an order of magnitude more stringent than previously appreciated.

The Expected Mass Function for Low‐Mass Galaxies in a Cold Dark Matter Cosmology: Is There a Problem?

2001 ◽  
Vol 563 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Weihsueh A. Chiu ◽  
Nickolay Y. Gnedin ◽  
Jeremiah P. Ostriker
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Mass Function ◽  
Low Mass

scholarly journals The lensing properties of subhaloes in massive elliptical galaxies in sterile neutrino cosmologies

2019 ◽  
Vol 491 (1) ◽  
pp. 1295-1310 ◽  
Author(s):  
Giulia Despali ◽  
Mark Lovell ◽  
Simona Vegetti ◽  
Robert A Crain ◽  
Benjamin D Oppenheimer
Keyword(s):  
Dark Matter ◽  
Power Spectrum ◽  
Galaxy Formation ◽  
Cold Dark Matter ◽  
Distribution Density ◽  
Sterile Neutrino ◽  
Power Spectra ◽  
Mass Function ◽  
Elliptical Galaxies ◽  
Hydrodynamical Simulations

ABSTRACT We use high-resolution hydrodynamical simulations run with the EAGLE model of galaxy formation to study the differences between the properties of – and subsequently the lensing signal from – subhaloes of massive elliptical galaxies at redshift 0.2, in Cold and Sterile Neutrino (SN) Dark Matter models. We focus on the two 7 keV SN models that bracket the range of matter power spectra compatible with resonantly produced SN as the source of the observed 3.5 keV line. We derive an accurate parametrization for the subhalo mass function in these two SN models relative to cold dark matter (CDM), as well as the subhalo spatial distribution, density profile, and projected number density and the dark matter fraction in subhaloes. We create mock lensing maps from the simulated haloes to study the differences in the lensing signal in the framework of subhalo detection. We find that subhalo convergence is well described by a lognormal distribution and that signal of subhaloes in the power spectrum is lower in SN models with respect to CDM, at a level of 10–80 per cent, depending on the scale. However, the scatter between different projections is large and might make the use of power spectrum studies on the typical scales of current lensing images very difficult. Moreover, in the framework of individual detections through gravitational imaging a sample of ≃30 lenses with an average sensitivity of $M_{\rm {sub}} = 5 \times 10^{7}\, {\rm M}_{\odot}$ would be required to discriminate between CDM and the considered sterile neutrino models.

The mass function of galaxy halos in a cold dark matter universe

1992 ◽  
Vol 394 ◽  
pp. 409 ◽  
Author(s):  
T. G. Brainerd ◽  
J. V. Villumsen
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Mass Function ◽  
Galaxy Halos

scholarly journals Clues to the nature of dark matter from first galaxies

2019 ◽  
Vol 489 (1) ◽  
pp. 487-496 ◽  
Author(s):  
Boyan K Stoychev ◽  
Keri L Dixon ◽  
Andrea V Macciò ◽  
Marvin Blank ◽  
Aaron A Dutton
Keyword(s):  
Dark Matter ◽  
Star Formation ◽  
Galaxy Formation ◽  
Cold Dark Matter ◽  
High Redshift ◽  
Formation Rate ◽  
Neutral Hydrogen ◽  
Mass Function ◽  
Stellar Mass ◽  
The Impact

ABSTRACT We use 38 high-resolution simulations of galaxy formation between redshift 10 and 5 to study the impact of a 3 keV warm dark matter (WDM) candidate on the high-redshift Universe. We focus our attention on the stellar mass function and the global star formation rate and consider the consequences for reionization, namely the neutral hydrogen fraction evolution and the electron scattering optical depth. We find that three different effects contribute to differentiate warm and cold dark matter (CDM) predictions: WDM suppresses the number of haloes with mass less than few 109 M⊙; at a fixed halo mass, WDM produces fewer stars than CDM, and finally at halo masses below 109 M⊙, WDM has a larger fraction of dark haloes than CDM post-reionization. These three effects combine to produce a lower stellar mass function in WDM for galaxies with stellar masses at and below 107 M⊙. For z > 7, the global star formation density is lower by a factor of two in the WDM scenario, and for a fixed escape fraction, the fraction of neutral hydrogen is higher by 0.3 at z ∼ 6. This latter quantity can be partially reconciled with CDM and observations only by increasing the escape fraction from 23 per cent to 34 per cent. Overall, our study shows that galaxy formation simulations at high redshift are a key tool to differentiate between dark matter candidates given a model for baryonic physics.

scholarly journals Galaxy Formation in a Universe Dominated by Cold Dark Matter

1987 ◽  
Vol 117 ◽  
pp. 360-360
Author(s):  
Edmund Bertschinger
Keyword(s):  
Dark Matter ◽  
Galaxy Formation ◽  
Globular Clusters ◽  
Cold Dark Matter ◽  
Mass Function ◽  
Spherical Approximation ◽  
De Sitter ◽  
Density Peaks ◽  
Lower Amplitude ◽  
Baryonic Mass

ABSTRACT The mass spectrum of bound baryonic systems (galaxies and globular clusters) is computed as a function of redshift in an Einstein-de Sitter (Ω=1) universe dominated by weakly interacting, cold dark matter. Baryons are assumed to fall into primordial density peaks in the cold particle distribution when the mass in the peaks exceeds the baryon Jeans mass. The distribution of peaks is computed using Gaussian statistics. As the universe expands the baryonic mass attached to a given peak increases because of infall (treated in a spherical approximation), and new peaks of lower amplitude become nonlinear. Globular clusters form first (by z∼40 if the galaxies represent a biased mass distribution). The remaining gas may be reheated to ∼10000 K if a few percent of globular cluster (or Pop. III) stars are very massive. Reheating increases the baryon Jeans mass and delays galaxy formation until z≲10. The present method reproduces the shape (but not the amplitude) of the Schechter galaxy mass function when merging of substructure is included in an approximate fashion.

scholarly journals An excess of small-scale gravitational lenses observed in galaxy clusters

Science ◽  
2020 ◽  
Vol 369 (6509) ◽  
pp. 1347-1351 ◽  
Author(s):  
Massimo Meneghetti ◽  
Guido Davoli ◽  
Pietro Bergamini ◽  
Piero Rosati ◽  
Priyamvada Natarajan ◽  
...  
Keyword(s):  
Dark Matter ◽  
Galaxy Clusters ◽  
Gravitational Lensing ◽  
Cold Dark Matter ◽  
Small Scale ◽  
Gravitational Lenses ◽  
Strong Lensing ◽  
Luminous Matter ◽  
Order Of Magnitude ◽  
The Universe

Cold dark matter (CDM) constitutes most of the matter in the Universe. The interplay between dark and luminous matter in dense cosmic environments, such as galaxy clusters, is studied theoretically using cosmological simulations. Observations of gravitational lensing are used to characterize the properties of substructures—the small-scale distribution of dark matter—in clusters. We derive a metric, the probability of strong lensing events produced by dark-matter substructure, and compute it for 11 galaxy clusters. The observed cluster substructures are more efficient lenses than predicted by CDM simulations, by more than an order of magnitude. We suggest that systematic issues with simulations or incorrect assumptions about the properties of dark matter could explain our results.

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.

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