Stellar splashback: the edge of the intracluster light

ABSTRACT We examine the outskirts of galaxy clusters in the C-EAGLE simulations to quantify the ‘edges’ of the stellar and dark matter distribution. The radius of the steepest slope in the dark matter, commonly used as a proxy for the splashback radius, is located at $\sim \, r_{200 \rm m}$; the strength and location of this feature depends on the recent mass accretion rate, in good agreement with previous work. Interestingly, the stellar distribution (or intracluster light, ICL) also has a well-defined edge, which is directly related to the splashback radius of the halo. Thus, detecting the edge of the ICL can provide an independent measure of the physical boundary of the halo, and the recent mass accretion rate. We show that these caustics can also be seen in the projected density profiles, but care must be taken to account for the influence of substructures and other non-diffuse material, which can bias and/or weaken the signal of the steepest slope. This is particularly important for the stellar material, which has a higher fraction bound in subhaloes than the dark matter. Finally, we show that the ‘stellar splashback’ feature is located beyond current observational constraints on the ICL, but these large projected distances (≫1 Mpc) and low surface brightnesses (μ ≫ 32 mag arcsec−2) can be reached with upcoming observational facilities such as the Vera C. Rubin Observatory, the Nancy Grace Roman Space Telescope, and Euclid.

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Dark matter distribution in superthin galaxies

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa1427 ◽

2020 ◽

Vol 495 (4) ◽

pp. 3722-3726

Author(s):

Ilia Kalashnikov

Keyword(s):

Dark Matter ◽

Surface Density ◽

Distribution Density ◽

Spherically Symmetric ◽

Matter Distribution ◽

Galactic Disc ◽

Density Profiles ◽

Visible Matter ◽

Simple Physical Model ◽

Dark Matter Distribution

ABSTRACT This paper presents a new method of calculating dark matter density profiles for superthin axial symmetric galaxies without a bulge. This method is based on a simple physical model, which includes an infinitely thin galactic disc immersed in a spherically symmetric halo of dark matter. To obtain the desired distribution density, it suffices to know a distribution of visible matter surface density in a galaxy and a dependence of angular velocity on the radius. As a byproduct, the well-known expression, which reproduces surface density of a superthin galaxy expressed through a rotation law, was obtained.

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Studying the Patterns of the Universe

Open Astronomy ◽

10.1515/astro-2017-0298 ◽

2011 ◽

Vol 20 (2) ◽

Author(s):

T. Sepp ◽

E. Tempel ◽

M. Gramann ◽

P. Nurmi ◽

M. Haupt

Keyword(s):

Dark Matter ◽

Galaxy Cluster ◽

Analytical Models ◽

Matter Distribution ◽

Galaxy Groups ◽

The Galaxy ◽

Dark Matter Distribution ◽

Distribution Studies ◽

The Universe ◽

Good Agreement

AbstractThe SDSS galaxy catalog is one of the best databases for galaxy distribution studies. The SDSS DR8 data is used to construct the galaxy cluster catalog. We construct the clusters from the calculated luminosity density field and identify denser regions. Around these peak regions we construct galaxy clusters. Another interesting question in cosmology is how observable galaxy structures are connected to underlying dark matter distribution. To study this we compare the SDSS DR7 galaxy group catalog with galaxy groups obtained from the semi-analytical Millennium N-Body simulation. Specifically, we compare the group richness, virial radius, maximum separation and velocity dispersion distributions and find a relatively good agreement between the mock catalog and observations. This strongly supports the idea that the dark matter distribution and galaxies in the semi-analytical models and observations are very closely linked.

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Cores vs. Cusps: Dark Matter Density Profiles in Spirals

Symposium - International Astronomical Union ◽

10.1017/s0074180900183469 ◽

2004 ◽

Vol 220 ◽

pp. 311-312

Author(s):

Gianfranco Gentile ◽

Uli Klein ◽

Paolo Salucci ◽

Daniela Vergani

Keyword(s):

Dark Matter ◽

Rotation Curve ◽

Spiral Galaxies ◽

Matter Density ◽

Matter Distribution ◽

Rotation Curves ◽

Density Profiles ◽

The Core ◽

Dark Matter Distribution ◽

A New Technique

We use photometric, Hα and Hi data to investigate the distribution of dark matter in spiral galaxies. A new technique for deriving the Hi rotation curve is presented. the final combined Hα+Hi rotation curves are symmetric, well resolved and extend to large radii. We perform the rotation curve decomposition into the luminous and dark matter contributions. the observations are confronted with different models of the dark matter distribution, including core-dominated and cusp-dominated halos as well as less conventional possibilities. the best agreement with the observations is found for the core-dominated halos.

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Imprint of Pressure on Characteristic Dark Matter Profiles: The Case of ESO0140040

Galaxies ◽

10.3390/galaxies8040074 ◽

2020 ◽

Vol 8 (4) ◽

pp. 74

Author(s):

Kuantay Boshkayev ◽

Talgar Konysbayev ◽

Ergali Kurmanov ◽

Orlando Luongo ◽

Marco Muccino

Keyword(s):

Dark Matter ◽

Complex Structure ◽

Matter Content ◽

Model Parameters ◽

Matter Distribution ◽

Density Profiles ◽

The Galaxy ◽

Dark Matter Distribution ◽

Observational Signature

We investigate the dark matter distribution in the spiral galaxy ESO0140040, employing the most widely used density profiles: the pseudo-isothermal, exponential sphere, Burkert, Navarro-Frenk-White, Moore and Einasto profiles. We infer the model parameters and estimate the total dark matter content from the rotation curve data. For simplicity, we assume that dark matter distribution is spherically symmetric without accounting for the complex structure of the galaxy. Our predictions are compared with previous results and the fitted parameters are statistically confronted for each profile. We thus show that although one does not include the galaxy structure it is possible to account for the same dynamics assuming that dark matter provides a non-zero pressure in the Newtonian approximation. In this respect, we solve the hydrostatic equilibrium equation and construct the dark matter pressure as a function for each profile. Consequently, we discuss the dark matter equation of state and calculate the speed of sound in dark matter. Furthermore, we interpret our results in view of our approach and we discuss the role of the refractive index as an observational signature to discriminate between our approach and the standard one.

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The splashback boundary of haloes in hydrodynamic simulations

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/stab1221 ◽

2021 ◽

Author(s):

Stephanie O’Neil ◽

David J Barnes ◽

Mark Vogelsberger ◽

Benedikt Diemer

Keyword(s):

Dark Matter ◽

Density Profile ◽

Accretion Rate ◽

Radial Density ◽

Density Profiles ◽

Hydrodynamic Simulations ◽

Mass Accretion Rate ◽

Significant Difference ◽

Satellite Galaxies

Abstract The splashback radius, Rsp, is a physically motivated halo boundary that separates infalling and collapsed matter of haloes. We study Rsp in the hydrodynamic and dark matter only IllustrisTNG simulations. The most commonly adopted signature of Rsp is the radius at which the radial density profiles are steepest. Therefore, we explicitly optimise our density profile fit to the profile slope and find that this leads to a $\sim 5\%$ larger radius compared to other optimisations. We calculate Rsp for haloes with masses between 1013 − 15M⊙ as a function of halo mass, accretion rate and redshift. Rsp decreases with mass and with redshift for haloes of similar M200m in agreement with previous work. We also find that Rsp/R200m decreases with halo accretion rate. We apply our analysis to dark matter, gas and satellite galaxies associated with haloes to investigate the observational potential of Rsp. The radius of steepest slope in gas profiles is consistently smaller than the value calculated from dark matter profiles. The steepest slope in galaxy profiles, which are often used in observations, tends to agree with dark matter profiles but is lower for less massive haloes. We compare Rsp in hydrodynamic and N-body dark matter only simulations and do not find a significant difference caused by the addition of baryonic physics. Thus, results from dark matter only simulations should be applicable to realistic haloes.

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Is diffuse intracluster light a good tracer of the galaxy cluster matter distribution?

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3680 ◽

2020 ◽

Vol 501 (1) ◽

pp. 1300-1315

Author(s):

H Sampaio-Santos ◽

Y Zhang ◽

R L C Ogando ◽

T Shin ◽

Jesse B Golden-Marx ◽

...

Keyword(s):

Dark Matter ◽

Total Mass ◽

Galaxy Cluster ◽

Stellar Mass ◽

Diffuse Light ◽

Matter Distribution ◽

The Galaxy ◽

Cluster Satellite ◽

Dark Matter Distribution ◽

Intracluster Light

ABSTRACT We explore the relation between diffuse intracluster light (central galaxy included) and the galaxy cluster (baryonic and dark) matter distribution using a sample of 528 clusters at 0.2 ≤ z ≤ 0.35 found in the Dark Energy Survey (DES) Year 1 data. The surface brightness of the diffuse light shows an increasing dependence on cluster total mass at larger radius, and appears to be self-similar with a universal radial dependence after scaling by cluster radius. We also compare the diffuse light radial profiles to the cluster (baryonic and dark) matter distribution measured through weak lensing and find them to be comparable. The IllustrisTNG galaxy formation simulation, TNG300, offers further insight into the connection between diffuse stellar mass and cluster matter distributions – the simulation radial profile of the diffuse stellar component does not have a similar slope with the total cluster matter content, although that of the cluster satellite galaxies does. Regardless of the radial trends, the amount of diffuse stellar mass has a low-scatter scaling relation with cluster’s total mass in the simulation, out-performing the total stellar mass of cluster satellite galaxies. We conclude that there is no consistent evidence yet on whether or not diffuse light is a faithful radial tracer of the cluster matter distribution. Nevertheless, both observational and simulation results reveal that diffuse light is an excellent indicator of the cluster’s total mass.

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NIHAO – XXIII. Dark matter density shaped by black hole feedback

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slaa058 ◽

2020 ◽

Vol 495 (1) ◽

pp. L46-L50 ◽

Cited By ~ 7

Author(s):

Andrea V Macciò ◽

Samuele Crespi ◽

Marvin Blank ◽

Xi Kang

Keyword(s):

Black Hole ◽

Dark Matter ◽

Stellar Mass ◽

Matter Density ◽

Matter Distribution ◽

Density Profiles ◽

Systematic Analysis ◽

Dark Matter Density ◽

Dark Matter Distribution ◽

Halo Masses

ABSTRACT We present a systematic analysis of the reaction of dark matter distribution to galaxy formation across more than eight orders of magnitude in stellar mass. We extend the previous work presented in the NIHAO-IV paper by adding 46 new high-resolution simulations of massive galaxies performed with the inclusion of black hole feedback. We show that outflows generated by the active galactic nucleus (AGN) are able to partially counteract the dark matter contraction due to the large central stellar component in massive haloes. The net effect is to relax the central dark matter distribution that moves to a less cuspy density profiles at halo mass larger than ≈3 × 1012 M⊙. The scatter around the mean value of the density profile slope (α) is fairly constant (Δα ≈ 0.3), with the exception of galaxies with halo masses around 1012 M⊙, at the transition from stellar to AGN feedback dominated systems, where the scatter increases by almost a factor of 3. We provide useful fitting formulae for the slope of the dark matter density profiles at few per cent of the virial radius for the whole stellar mass range: 105–1012 M⊙ (2 × 109 to 5 × 1013 M⊙ in halo mass).

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DARK MATTER DYNAMICS AND INDIRECT DETECTION

Modern Physics Letters A ◽

10.1142/s0217732305017391 ◽

2005 ◽

Vol 20 (14) ◽

pp. 1021-1036 ◽

Cited By ~ 82

Author(s):

GIANFRANCO BERTONE ◽

DAVID MERRITT

Keyword(s):

Dark Matter ◽

Total Mass ◽

Galactic Center ◽

Direct Detection ◽

Indirect Detection ◽

Matter Distribution ◽

Dark Matter Distribution ◽

Particle Dark Matter ◽

The Universe ◽

Rule Out

Non-baryonic, or "dark", matter is believed to be a major component of the total mass budget of the Universe. We review the candidates for particle dark matter and discuss the prospects for direct detection (via interaction of dark matter particles with laboratory detectors) and indirect detection (via observations of the products of dark matter self-annihilations), focusing in particular on the Galactic center, which is among the most promising targets for indirect detection studies. The gravitational potential at the Galactic center is dominated by stars and by the supermassive black hole, and the dark matter distribution is expected to evolve on sub-parsec scales due to interaction with these components. We discuss the dominant interaction mechanisms and show how they can be used to rule out certain extreme models for the dark matter distribution, thus increasing the information that can be gleaned from indirect detection searches.

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