The evolution of galaxy intrinsic alignments in the MassiveBlackII universe

ABSTRACT We investigate the redshift evolution of the intrinsic alignments (IAs) of galaxies in the MassiveBlackII (MBII) simulation. We select galaxy samples above fixed subhalo mass cuts ($M_h\gt 10^{11,12,13}\,\mathrm{M}_{\odot }\, h^{-1}$) at z = 0.6 and trace their progenitors to z = 3 along their merger trees. Dark matter components of z = 0.6 galaxies are more spherical than their progenitors while stellar matter components tend to be less spherical than their progenitors. The distribution of the galaxy–subhalo misalignment angle peaks at ∼10 deg with a mild increase with time. The evolution of the ellipticity–direction (ED) correlation amplitude ω(r) of galaxies (which quantifies the tendency of galaxies to preferentially point towards surrounding matter overdensities) is governed by the evolution in the alignment of underlying dark matter (DM) subhaloes to the matter density of field, as well as the alignment between galaxies and their DM subhaloes. At scales $\sim 1~\mathrm{Mpc}\, h^{-1}$, the alignment between DM subhaloes and matter overdensity gets suppressed with time, whereas the alignment between galaxies and DM subhaloes is enhanced. These competing tendencies lead to a complex redshift evolution of ω(r) for galaxies at $\sim 1~\mathrm{Mpc}\, h^{-1}$. At scales $\gt 1~\mathrm{Mpc}\, h^{-1}$, alignment between DM subhaloes and matter overdensity does not evolve significantly; the evolution of the galaxy–subhalo misalignment therefore leads to an increase in ω(r) for galaxies by a factor of ∼4 from z = 3 to 0.6 at scales $\gt 1~\mathrm{Mpc}\, h^{-1}$. The balance between competing physical effects is scale dependent, leading to different conclusions at much smaller scales ($\sim 0.1~\mathrm{Mpc}\, h^{-1}$).

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A test of the standard dark matter density evolution law using galaxy clusters and cosmic chronometers

The European Physical Journal C ◽

10.1140/epjc/s10052-022-09987-3 ◽

2022 ◽

Vol 82 (1) ◽

Author(s):

Kamal Bora ◽

R. F. L. Holanda ◽

Shantanu Desai ◽

S. H. Pereira

Keyword(s):

Dark Matter ◽

Galaxy Cluster ◽

Matter Density ◽

Density Evolution ◽

Full Agreement ◽

Evolution Law ◽

Dark Matter Density ◽

The Galaxy ◽

Mass Fractions ◽

Frw Metric

AbstractIn this paper, we implement a test of the standard law for the dark matter density evolution as a function of redshift. For this purpose, only a flat universe and the validity of the FRW metric are assumed. A deformed dark matter density evolution law is considered, given by $$\rho _c(z) \propto (1+z)^{3+\epsilon }$$ ρ c ( z ) ∝ ( 1 + z ) 3 + ϵ , and constraints on $$\epsilon $$ ϵ are obtained by combining the galaxy cluster gas mass fractions with cosmic chronometers measurements. We find that $$\epsilon =0$$ ϵ = 0 within 2$$\sigma $$ σ c.l., in full agreement with other recent analyses.

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Search for topological defect dark matter with a global network of optical magnetometers

Nature Physics ◽

10.1038/s41567-021-01393-y ◽

2021 ◽

Vol 17 (12) ◽

pp. 1396-1401

Author(s):

Samer Afach ◽

Ben C. Buchler ◽

Dmitry Budker ◽

Conner Dailey ◽

Andrei Derevianko ◽

...

Keyword(s):

Dark Matter ◽

Domain Walls ◽

Topological Defect ◽

Topological Defects ◽

Matter Density ◽

Global Network ◽

The Earth ◽

The World ◽

The Galaxy ◽

Long Operation

AbstractUltralight bosons such as axion-like particles are viable candidates for dark matter. They can form stable, macroscopic field configurations in the form of topological defects that could concentrate the dark matter density into many distinct, compact spatial regions that are small compared with the Galaxy but much larger than the Earth. Here we report the results of the search for transient signals from the domain walls of axion-like particles by using the global network of optical magnetometers for exotic (GNOME) physics searches. We search the data, consisting of correlated measurements from optical atomic magnetometers located in laboratories all over the world, for patterns of signals propagating through the network consistent with domain walls. The analysis of these data from a continuous month-long operation of GNOME finds no statistically significant signals, thus placing experimental constraints on such dark matter scenarios.

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Detecting dark photons from atomic rearrangement in the galaxy

Journal of High Energy Physics ◽

10.1007/jhep04(2021)016 ◽

2021 ◽

Vol 2021 (4) ◽

Author(s):

James Eiger ◽

Michael Geller

Keyword(s):

Dark Matter ◽

Ground State ◽

Bound State ◽

Current Data ◽

Dark Sector ◽

Atomic Process ◽

The Galaxy ◽

Atomic States ◽

Atomic Rearrangement

Abstract We study a new dark sector signature for an atomic process of “rearrangement” in the galaxy. In this process, a hydrogen-like atomic dark matter state together with its anti-particle can rearrange to form a highly-excited bound state. This bound state will then de-excite into the ground state emitting a large number of dark photons that can be measured in experiments on Earth through their kinetic mixing with the photon. We find that for DM masses in the GeV range, the dark photons have enough energy to pass the thresholds of neutrino observatories such as Borexino and Super-Kamiokande that can probe for our scenario even when our atomic states constitute a small fraction of the total DM abundance. We study the corresponding bounds on the parameters of our model from current data as well as the prospects for future detectors.

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Dark matter candidates in a type-II radiative neutrino mass model

Journal of High Energy Physics ◽

10.1007/jhep06(2021)072 ◽

2021 ◽

Vol 2021 (6) ◽

Author(s):

Roberto A. Lineros ◽

Mathias Pierre

Keyword(s):

Dark Matter ◽

Neutral Particle ◽

Matter Density ◽

Indirect Detection ◽

Dark Matter Candidate ◽

Neutrino Masses ◽

Type Ii ◽

Mass Model ◽

Direct And Indirect Detection

Abstract We explore the connection between Dark Matter and neutrinos in a model inspired by radiative Type-II seessaw and scotogenic scenarios. In our model, we introduce new electroweakly charged states (scalars and a vector-like fermion) and impose a discrete ℤ2 symmetry. Neutrino masses are generated at the loop level and the lightest ℤ2-odd neutral particle is stable and it can play the role of a Dark Matter candidate. We perform a numerical analysis of the model showing that neutrino masses and flavour structure can be reproduced in addition to the correct dark matter density, with viable DM masses from 700 GeV to 30 TeV. We explore direct and indirect detection signatures and show interesting detection prospects by CTA, Darwin and KM3Net and highlight the complementarity between these observables.

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Celestial-body focused dark matter annihilation throughout the Galaxy

Physical Review D ◽

10.1103/physrevd.103.075030 ◽

2021 ◽

Vol 103 (7) ◽

Author(s):

Rebecca K. Leane ◽

Tim Linden ◽

Payel Mukhopadhyay ◽

Natalia Toro

Keyword(s):

Dark Matter ◽

Celestial Body ◽

Dark Matter Annihilation ◽

The Galaxy

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On the formation and stability of fermionic dark matter halos in a cosmological framework

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3986 ◽

2020 ◽

Author(s):

Carlos R Argüelles ◽

Manuel I Díaz ◽

Andreas Krut ◽

Rafael Yunis

Keyword(s):

Black Hole ◽

Dark Matter ◽

Space Distribution ◽

Coarse Grained ◽

Dark Matter Halos ◽

The Core ◽

The Galaxy ◽

Gravitating Systems ◽

The Given ◽

First Time

Abstract The formation and stability of collisionless self-gravitating systems is a long standing problem, which dates back to the work of D. Lynden-Bell on violent relaxation, and extends to the issue of virialization of dark matter (DM) halos. An important prediction of such a relaxation process is that spherical equilibrium states can be described by a Fermi-Dirac phase-space distribution, when the extremization of a coarse-grained entropy is reached. In the case of DM fermions, the most general solution develops a degenerate compact core surrounded by a diluted halo. As shown recently, the latter is able to explain the galaxy rotation curves while the DM core can mimic the central black hole. A yet open problem is whether this kind of astrophysical core-halo configurations can form at all, and if they remain stable within cosmological timescales. We assess these issues by performing a thermodynamic stability analysis in the microcanonical ensemble for solutions with given particle number at halo virialization in a cosmological framework. For the first time we demonstrate that the above core-halo DM profiles are stable (i.e. maxima of entropy) and extremely long lived. We find the existence of a critical point at the onset of instability of the core-halo solutions, where the fermion-core collapses towards a supermassive black hole. For particle masses in the keV range, the core-collapse can only occur for Mvir ≳ E9M⊙ starting at zvir ≈ 10 in the given cosmological framework. Our results prove that DM halos with a core-halo morphology are a very plausible outcome within nonlinear stages of structure formation.

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Direct detection of atomic dark matter in white dwarfs

Journal of High Energy Physics ◽

10.1007/jhep03(2021)166 ◽

2021 ◽

Vol 2021 (3) ◽

Author(s):

David Curtin ◽

Jack Setford

Keyword(s):

Dark Matter ◽

Energy Loss ◽

Cooling Rate ◽

White Dwarf ◽

White Dwarfs ◽

Luminosity Function ◽

Direct Detection ◽

Matter Density ◽

Mixing Parameter ◽

First Time

Abstract Dark matter could have a dissipative asymmetric subcomponent in the form of atomic dark matter (aDM). This arises in many scenarios of dark complexity, and is a prediction of neutral naturalness, such as the Mirror Twin Higgs model. We show for the first time how White Dwarf cooling provides strong bounds on aDM. In the presence of a small kinetic mixing between the dark and SM photon, stars are expected to accumulate atomic dark matter in their cores, which then radiates away energy in the form of dark photons. In the case of white dwarfs, this energy loss can have a detectable impact on their cooling rate. We use measurements of the white dwarf luminosity function to tightly constrain the kinetic mixing parameter between the dark and visible photons, for DM masses in the range 10−5–105 GeV, down to values of ϵ ∼ 10−12. Using this method we can constrain scenarios in which aDM constitutes fractions as small as 10−3 of the total dark matter density. Our methods are highly complementary to other methods of probing aDM, especially in scenarios where the aDM is arranged in a dark disk, which can make direct detection extremely difficult but actually slightly enhances our cooling constraints.

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What to expect when using globular clusters as tracers of the total mass distribution in Milky Way-mass galaxies

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab196 ◽

2021 ◽

Vol 502 (2) ◽

pp. 2828-2844

Author(s):

Meghan E Hughes ◽

Prashin Jethwa ◽

Michael Hilker ◽

Glenn van de Ven ◽

Marie Martig ◽

...

Keyword(s):

Dark Matter ◽

Radial Distribution ◽

Globular Clusters ◽

Dominant Factor ◽

Quality Uncertainty ◽

Dynamical Models ◽

Accuracy And Precision ◽

The Galaxy ◽

Dark Matter Distribution ◽

Ideal Tracer

ABSTRACT Dynamical models allow us to connect the motion of a set of tracers to the underlying gravitational potential, and thus to the total (luminous and dark) matter distribution. They are particularly useful for understanding the mass and spatial distribution of dark matter (DM) in a galaxy. Globular clusters (GCs) are an ideal tracer population in dynamical models, since they are bright and can be found far out into the halo of galaxies. We aim to test how well Jeans-Anisotropic-MGE (JAM) models using GCs (positions and line-of-sight velocities) as tracers can constrain the mass and radial distribution of DM haloes. For this, we use the E-MOSAICS suite of 25 zoom-in simulations of L* galaxies. We find that the DM halo properties are reasonably well recovered by the JAM models. There is, however, a strong correlation between how well we recover the mass and the radial distribution of the DM and the number of GCs in the galaxy: the constraints get exponentially worse with fewer GCs, and at least 150 GCs are needed in order to guarantee that the JAM model will perform well. We find that while the data quality (uncertainty on the radial velocities) can be important, the number of GCs is the dominant factor in terms of the accuracy and precision of the measurements. This work shows promising results for these models to be used in extragalactic systems with a sample of more than 150 GCs.

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