The Power Spectrum Dependence of Dark Matter Halo Concentrations

Eke, V. R.; Navarro, Julio F.; Steinmetz, Matthias

doi:10.1086/321345

Cited by 472 publications

(774 citation statements)

References 61 publications

Supporting

Mentioning

720

Contrasting

Order By: Relevance

“…Numerical simulations of galaxy formation find a correlation between ρ NFW and R NFW , which depends on the cosmological model (e.g., Navarro et al 1997;Avila-Reese et al 2001;Eke et al 2001;Bullock et al 2001). Often this correlation is expressed using the concentration parameter C ≡ R vir /R NFW , and V h or M h , the characteristic velocity or mass at R vir .…”

Section: Collisionless Dark Matter: a Comparison With Lcdm Simulationsmentioning

confidence: 99%

Dynamical signatures of a ΛCDM-halo and the distribution of the baryons in M 33

Corbelli

Thilker

Zibetti

et al. 2014

A&A

153

View full text Add to dashboard Cite

Aims. We determine the mass distribution of stars, gas, and dark matter in M 33 to test cosmological models of galaxy formation and evolution. Methods. We map the neutral atomic gas content of M 33 using high resolution Very Large Array and Green Bank Telescope observations of the 21 cm HI line emission. A tilted ring model is fitted to the HI datacube to determine the varying spatial orientation of the extended gaseous disk and the rotation curve. We derive the stellar mass surface density map of M 33's optical disk via pixel-SED fitting methods based on population synthesis models that allow for positional changes in star formation history. Stellar and gas maps are used in the dynamical analysis of the rotation curve to constrain the dark halo properties. Results. The disk of M 33 warps from 8 kpc outward without substantial change of its inclination with respect to the line of sight; the line of nodes rotates clockwise toward the direction of M 31. Rotational velocities rise steeply with radius in the inner disk, reaching 100 km s −1 in 4 kpc, then the rotation curve becomes more perturbed and flatter with velocities as high as 120-130 km s −1 out to 2.7 R 25 . The stellar surface density map highlights a star-forming disk with a varying mass-to-light ratio. At larger radii, a dynamically relevant fraction of the baryons are in gaseous form. A dark matter halo with a Navarro-Frenk-White density profile, as predicted by hierarchical clustering and structure formation in a ΛCDM cosmology, provides the best fits to the rotation curve. Dark matter is relevant at all radii in shaping the rotation curve and the most likely dark halo has a concentration C 9.5 and a total mass of 4.3(±1.0) × 10 11 M . This imples a baryonic fraction of order 0.02 and the evolutionary history of this galaxy should therefore account for loss of a large fraction of its original baryonic content.

show abstract

Section: Collisionless Dark Matter: a Comparison With Lcdm Simulationsmentioning

confidence: 99%

Dynamical signatures of a ΛCDM-halo and the distribution of the baryons in M 33

Corbelli

Thilker

Zibetti

et al. 2014

A&A

153

View full text Add to dashboard Cite

show abstract

“…Cosmological simulations show that the halo concentration depends on both halo mass and redshift at which the halo is identified (e.g. Bullock et al 2001;Eke, Navarro & Steinmetz 2001;Zhao et al 2003Zhao et al , 2009Macciò et al 2007). Here we adopt the recent simulation result of Prada et al (2012) to compute c for a halo with a given mass at a given redshift.…”

Section: Formation History and Structure Of Dark Matter Halosmentioning

confidence: 99%

Formation of disc galaxies in preheated media: a preventative feedback model

Lu¹,

Mo²

2014

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We introduce a semi-analytic galaxy formation model implementing a self-consistent treatment for the hot halo gas configuration and the assembly of central disks. Using the model, we explore a preventative feedback model, in which the circum-halo medium is assumed to be preheated up to a certain entropy level by early starbursts or other processes, and compare it with an ejective feedback model, in which baryons are first accreted into dark matter halos and subsequently ejected out by feedback. The model demonstrates that when the medium is preheated to an entropy comparable to the halo virial entropy the baryon accretion can be largely reduced and delayed. In addition, the preheated medium can establish an extended low density gaseous halo when it accretes into the dark matter halos, and result in a specific angular momentum of the cooling gas large enough to form central disks as extended as those observed. Combined with simulated halo assembly histories, the preventative feedback model can reproduce remarkably well a number of observational scaling relations. These include the cold baryon (stellar plus cold gas) mass fraction-halo mass relations, star formation histories, disk size-stellar mass relation and its evolution, and the number density of low-mass galaxies as a function of redshift. In contrast, the conventional ejective feedback model fails to reproduce these observational trends. Using the model, we demonstrate that the properties of disk galaxies are closely tied to the thermal state of hot halo gas and even possibly the circum-halo medium, which suggests that observational data for the disk properties and circum-galactic hot/warm medium may jointly provide interesting constraints for galaxy formation models.

show abstract

“…Navarro et al 1997;Avila-Reese et al 2001;Eke et al 2001;Bullock et al 2001). Often this correlation is expressed using the concentration parameter C ≡ R Δ /R NFW and M Δ or V Δ .…”

Section: Dark Matter Halo Modelsmentioning

confidence: 99%

A wide-field H I mosaic of Messier 31

Corbelli

Lorenzoni

Walterbos³

et al. 2010

A&A

163

229

View full text Add to dashboard Cite

Aims. We test cosmological models of structure formation using the rotation curve of the nearest spiral galaxy, M 31, determined using a recent deep, full-disk 21-cm imaging survey smoothed to 466 pc resolution. Methods. We fit a tilted ring model to the HI data from 8 to 37 kpc and establish conclusively the presence of a dark halo and its density distribution via dynamical analysis of the rotation curve. Results. The disk of M 31 warps from 25 kpc outwards and becomes more inclined with respect to our line of sight. Newtonian dynamics without a dark matter halo provide a very poor fit to the rotation curve. In the framework of modified Newtonian dynamic (MOND) however the 21-cm rotation curve is well fitted by the gravitational potential traced by the baryonic matter density alone. The inclusion of a dark matter halo with a density profile as predicted by hierarchical clustering and structure formation in a ΛCDM cosmology makes the mass model in newtonian dynamic compatible with the rotation curve data. The dark halo concentration parameter for the best fit is C = 12 and its total mass is 1.2 × 10 12 M . If a dark halo model with a constant-density core is considered, the core radius has to be larger than 20 kpc in order for the model to provide a good fit to the data. We extrapolate the best-fit ΛCDM and constant-density core mass models to very large galactocentric radii, comparable to the size of the dark matter halo. A comparison of the predicted mass with the M 31 mass determined at such large radii using other dynamical tracers, confirms the validity of our results. In particular the ΛCDM dark halo model which best fits the 21-cm data well reproduces the mass of M 31 traced out to 560 kpc. Our best estimate for the total mass of M 31 is 1.3 × 10 12 M , with 12% baryonic fraction and only 6% of the baryons in the neutral gas phase.

show abstract

The Power Spectrum Dependence of Dark Matter Halo Concentrations

Cited by 472 publications

References 61 publications

Dynamical signatures of a ΛCDM-halo and the distribution of the baryons in M 33

Dynamical signatures of a ΛCDM-halo and the distribution of the baryons in M 33

Formation of disc galaxies in preheated media: a preventative feedback model

A wide-field H I mosaic of Messier 31

Contact Info

Product

Resources

About