Density profiles of dark matter haloes: diversity and dependence on environment

Avila-Reese, Vladimir; Firmani, C.; Klypin, Anatoly; Kravtsov, Andrey V.

doi:10.1046/j.1365-8711.1999.02968.x

Cited by 95 publications

(114 citation statements)

References 57 publications

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“…Reported in columns (6) to (14) are, respectively, the virial mass, M v , the maximum circular velocity, V max , the c 1/5 and NFW concentration parameters, the average density within 1% the virial radius, and three core radii estimated by different criteria (the latter quantities apply only to halos simulated with v rms ; see x 4.2). The NFW and c 1/5 concentrations are defined, respectively, as the ratios between R v and the NFW scale radius and those between R v and the radius where one-fifth of M v is contained (Avila-Reese et al 1999). As found in previous results, halos with masses below the truncation mass in the power spectrum tend to be less concentrated than ÃCDM halos of similar masses (Avila-Reese et al 2001; Bode et al 2001;Knebe et al 2002).…”

Section: The Structure Of Halos At the Scale Of Dampingmentioning

confidence: 85%

On the Structure of Dark Matter Halos at the Damping Scale of the Power Spectrum with and without Relict Velocities

Colín

Valenzuela

Avila-Reese

2008

ApJ

106

115

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We report a series of high-resolution cosmological N -body simulations designed to explore the formation and properties of dark matter halos with masses close to the damping scale of the primordial power spectrum of density fluctuations. We further investigate the effect that the addition of a random component, v rms , into the particle velocity field has on the structure of halos. We adopted as a fiducial model a ÃWDM cosmology with a nonthermal sterile neutrino mass of 0.5 keV. The filtering mass corresponds then to M f ¼ 2:6 ; 10 12 h À1 M . Halos of masses close to M f were simulated with several million particles. The results show that, on the one hand, the inner density slope of these halos (at radii P0:02 the virial radius R v ) is systematically steeper than the one corresponding to the NFW fit or to the CDM counterpart. On the other hand, the overall density profile (radii >0:02R v ) is less curved and less concentrated than the NFW fit, with an outer slope shallower than À3. For simulations with v rms , the inner halo density profiles flatten significantly at radii smaller than 2Y3 h À1 kpc (P0:010R v Y0:015R v ). A constant density core is not detected in our simulations, with the exception of one halo for which the flat core radius is %1 h À1 kpc. Nevertheless, if ''cored'' density profiles are used to fit the halo profiles, the inferred core radii are %(0:1Y0:8) h À1 kpc, in rough agreement with theoretical predictions based on phase-space constraints and on dynamical models of warm gravitational collapse. A reduction of v rms by a factor of 3 produces a modest decrease in core radii, by less than a factor of 1.5. We discuss the extension of our results into several contexts, for example, to the structure of the cold DM microhalos at the damping scale of this model.

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Section: The Structure Of Halos At the Scale Of Dampingmentioning

confidence: 85%

On the Structure of Dark Matter Halos at the Damping Scale of the Power Spectrum with and without Relict Velocities

Colín

Valenzuela

Avila-Reese

2008

ApJ

106

115

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“…Bullock et al (2001) found that halos in dense environments are more truncated than their isolated counterparts of the same virial mass. Avila-Reese et al (1999, 2005 found that halos in cluster regions are more concentrated than isolated halos. N-body simulations of cluster formation and evolution (Ghigna et al 1998;Ghigna et al 2000) find that the dominant interactions are between the global cluster tidal field and individual galaxies after z = 2.…”

Section: Discussionmentioning

confidence: 99%

Truncation of galaxy dark matter halos in high density environments

Limousin

Kneib

Bardeau

et al. 2006

A&A

107

139

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Aims. Our aim is to constrain the properties of dark matter halos inhabiting high density environments, such as is the case in massive galaxy clusters. Methods. We use galaxy-galaxy lensing techniques that utilize a maximum likelihood method to constrain the parameters of the lenses. It has been demonstrated that such a technique provides strong constraints on the parameters that characterize a galaxy halo, as well as on the aperture mass of these halos. In this analysis, we only use weak shear data and do not include strong lensing constraints.Results. We present the results of a study of galaxy-galaxy lensing in a homogeneous sample of massive x-ray luminous clusters at z ∼ 0.2. These have been observed in three bands with the cfh12k instrument. We find dark matter halos in these clusters to be compact compared to those inferred around isolated field galaxies of equivalent luminosity at this redshift: the half mass radius is found to be smaller than 50 kpc, with a mean total mass of order 0.2× 10 12 M . This is in good agreement with previous galaxy-galaxy lensing results and with numerical simulations, in particular with the tidal stripping scenario. We thus provide a strong confirmation of tidal truncation from a homogeneous sample of galaxy clusters. Moreover, it is the first time that cluster galaxies are probed successfully using galaxy-galaxy lensing techniques from ground based data.

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“…In their simulations on formation of dark halos, Avila-Reese et al (1999) find that most halos tend to have density profiles ∝r −β where β falls in the range 2.5-3.8, in the outer region. Bournaud et al (2003) find from their simulations, that dark halos should extend to at least ten times further than their stellar disks, ) as a function of the galactocentric radius, for the best-fit halo (p = 2) and the isothermal halo (p = 1).…”

Section: Comparison With Other Deductionsmentioning

confidence: 99%

Constraints on the halo density profile using HI flaring in the outer Galaxy

Narayan¹,

Saha²,

Jog³

2005

A&A

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Abstract. The observed flaring of HI disk in the outer region of galaxies has been used in the past to determine the shape of the dark matter halo. Previous studies based on this concept suggest a slightly oblate halo (axis ratio ∼0.8) for our Galaxy. We reinvestigate this problem by calculating the HI scaleheight in the outer Galaxy to a larger radial distance, and by studying its dependence on the shape and the density profile of the halo. We find that a simple isothermal infinite halo of any shape-oblate or prolate, is not able to account for the observed flaring. Instead we show that a spherical halo with density falling faster than isothermal halo in the outer region provides a better fit to the observed HI flaring as well as the observed rotation curve of our Galaxy. These halos have about 95% of their mass within a few hundreds of kpc for R • = 8.5 kpc and Θ • = 220 km s −1 , the central density and core radius can be constrained to the range ρ • = 0.035−0.06 M pc −3 and R c = 8−10 kpc. Our claim for such "finite-sized" spherical halos is supported by recent literature on numerical simulation studies of halo formation as well as analyses of SDSS data.

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Density profiles of dark matter haloes: diversity and dependence on environment

Cited by 95 publications

References 57 publications

On the Structure of Dark Matter Halos at the Damping Scale of the Power Spectrum with and without Relict Velocities

On the Structure of Dark Matter Halos at the Damping Scale of the Power Spectrum with and without Relict Velocities

Truncation of galaxy dark matter halos in high density environments

Constraints on the halo density profile using HI flaring in the outer Galaxy

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