The Epoch of Reionization in Warm Dark Matter Scenarios

In this paper we investigate how the Reionization process is affected by early galaxy formation in different cosmological scenarios. We use a semi-analytic model with suppressed initial power spectra to obtain the UV Luminosity Function in thermal Warm Dark Matter and sterile neutrino cosmologies. We retrace the ionization history of intergalactic medium with hot stellar emission only, exploiting fixed and variable photons escape fraction models (fesc). For each cosmology, we find an upper limit to fixed fesc, which guarantees the completion of the process at z<6.7. The analysis is tested with two limit hypothesis on high-z ionized hydrogen volume fraction, comparing our predictions with observational results.

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The Epoch of Reionization in Warm Dark Matter Scenarios

10.20944/preprints202106.0521.v1 ◽

2021 ◽

Author(s):

M. Romanello ◽

N. Menci ◽

M. Castellano

Keyword(s):

Dark Matter ◽

Galaxy Formation ◽

Volume Fraction ◽

Power Spectra ◽

Neutral Hydrogen ◽

Wave Model ◽

Hydrogen Ionization ◽

Uv Photons ◽

Initial Power ◽

Mass Dependent

In this paper we investigate how the Reionization process is affected by early galaxy formation in different cosmological scenarios. We use a semi-analytic model with suppressed initial power spectra to obtain the UV Luminosity Function in thermal Warm Dark Matter and sterile neutrino cosmologies. We retrace the ionization history of intergalactic medium with hot stellar emission only, exploiting fixed and mass-dependent photons escape fraction (fesc). For each cosmology, we find an upper limit to fixed fesc, which guarantees the completion of the process at z&lt;6.7. The analysis is tested with two limit hypothesis on high-z ionized hydrogen volume fraction, comparing our predictions with observational results. We then implement a blast-wave model, which explains the genesis of UV photons escape fraction in the context of feedback and co-evolution between galaxies and Active Galactic Nuclei. Including the AGNs contribution, we find that the neutral hydrogen ionization is almost complete at z&lt;7, with a weak dependence on initial gaseous ionized fraction and accretion UV spectral slope.

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

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stz3068 ◽

2019 ◽

Vol 491 (1) ◽

pp. 1295-1310 ◽

Cited By ~ 4

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.

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Does the reionization model influence the constraints on dark matter decay or annihilation?

Journal of Cosmology and Astroparticle Physics ◽

10.1088/1475-7516/2021/12/034 ◽

2021 ◽

Vol 2021 (12) ◽

pp. 034

Author(s):

Lu Chen ◽

Ke Wang

Keyword(s):

Dark Matter ◽

Star Formation ◽

Star Formation Rate ◽

Formation Rate ◽

Power Spectra ◽

Microwave Background ◽

Dark Matter Annihilation ◽

Planck Data ◽

Upper Limit ◽

History Of

Abstract If dark matter decay or annihilate, a large amount of energy and particles would be released into the cosmic plasma. Therefore, they could modify the thermal and ionization history of our universe, then leave footprints on the cosmic microwave background power spectra. In this paper, we take dark matter annihilation as an example and investigate whether different reionization models influence the constraints on dark matter annihilation. We consider the ionization history including both dark matter annihilation and star formation, then put constraints on DM annihilation. Combining the latest Planck data, BAO data, SNIa measurement, Q HII constraints from observations of quasars, as well as the star formation rate density from UV and IR data, the optical depth is τ = 0.0571+0.0005 -0.0006 at 68%C.L. and the upper limit of ϵ0 f d reads 2.7765 × 10-24 at 95%C.L.. By comparison, we also constrain dark matter annihilation in the instantaneous reionization model from the same data combination except the Q HII constraints and star formation rate density. We get τ = 0.0559+0.0069 -0.0076 at 68%C.L. and the upper limit of ϵ0 f d is 2.8468 × 10-24 at 95%C.L.. This indicates various reionization models have little influence (≲ 2.5%) on constraining parameters of dark matter decay or annihilation.

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Observational tests of wave VS. particle dark matter predictions for early galaxy formation in the hubble frontier fields

10.5353/th_991044081528803414 ◽

2018 ◽

Author(s):

Yi-lok, Enoch Leung

Keyword(s):

Dark Matter ◽

Galaxy Formation ◽

Particle Dark Matter ◽

Early Galaxy

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Dark Matter Substructure and Dwarf Galactic Satellites

Advances in Astronomy ◽

10.1155/2010/281913 ◽

2010 ◽

Vol 2010 ◽

pp. 1-21 ◽

Cited By ~ 116

Author(s):

Andrey Kravtsov

Keyword(s):

Dark Matter ◽

Galaxy Formation ◽

Luminosity Function ◽

Cold Dark Matter ◽

Dynamical Friction ◽

Density Profiles ◽

Tidal Forces ◽

Central Regions ◽

Galactic Satellites ◽

Virial Mass

A decade ago cosmological simulations of increasingly higher resolution were used to demonstrate that virialized regions of Cold Dark Matter (CDM) halos are filled with a multitude of dense, gravitationally bound clumps. These dark mattersubhalosare central regions of halos that survived strong gravitational tidal forces and dynamical friction during the hierarchical sequence of merging and accretion via which the CDM halos form. Comparisons with observations revealed that there is a glaring discrepancy between abundance of subhalos and luminous satellites of the Milky Way and Andromeda as a function of their circular velocity or bound mass within a fixed aperture. This large discrepancy, which became known as the “substructure” or the “missing satellites” problem, begs for an explanation. In this paper, the author reviews the progress made during the last several years both in quantifying the problem and in exploring possible scenarios in which it could be accommodated and explained in the context of galaxy formation in the framework of the CDM paradigm of structure formation. In particular, he shows that the observed luminosity function, radial distribution, and the remarkable similarity of the inner density profiles of luminous satellites can be understood within hierarchical CDM framework using a simple model in which efficiency of star formation monotonically decreases with decreasing virial mass satellites had before their accretionwithout any actual sharp galaxy formation threshold.

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THE LINK BETWEEN GALAXIES AND DARK MATTER

International Journal of Modern Physics D ◽

10.1142/s0218271811019840 ◽

2011 ◽

Vol 20 (10) ◽

pp. 1771-1777

Author(s):

HOUJUN MO

Keyword(s):

Dark Matter ◽

Galaxy Formation ◽

Luminosity Function ◽

The Other ◽

Dark Matter Halos ◽

Galaxy Formation And Evolution ◽

The Galaxy ◽

Galaxy Halo ◽

Formation And Evolution ◽

The Universe

Given that dark matter is gravitationally dominant in the universe, and that galaxy formation is closely related to dark matter halos, a key first step in understanding galaxy formation and evolution in the CDM paradigm is to quantify the galaxy-halo connection for galaxies of different properties. Here I will present results about the halo/galaxy connection obtained from two different methods. One is based on the conditional luminosity function, which describes the occupation of galaxies in halos of different masses, and the other is based on galaxy systems properly selected to represent dark halos.

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DARK MATTER IN SPIRAL HALOS AND THE HALO MASS FUNCTION

International Journal of Modern Physics D ◽

10.1142/s0218271894000988 ◽

1994 ◽

Vol 03 (supp01) ◽

pp. 87-92

Author(s):

KEITH M. ASHMAN ◽

PAOLO SALUCCI ◽

MASSIMO PERSIC

Keyword(s):

Dark Matter ◽

Hierarchical Clustering ◽

Galaxy Formation ◽

Luminosity Function ◽

Mass Function ◽

Dark Halo ◽

Constant Mass ◽

High Luminosity ◽

The Galaxy ◽

Galaxy Luminosity Function

Evidence that low-luminosity spirals have a higher dark matter fraction than their high-luminosity counterparts is discussed. The empirical correlation between dark matter fraction and luminosity is used, in conjunction with the galaxy luminosity function of spirals, to derive the dark halo mass function of these galaxies. The mass function is shown to be consistent with hierarchical clustering models of galaxy formation. This contrasts with previous results based on the assumption of a constant mass-to-light ratio for all spirals, which predict too many low-luminosity galaxies.

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