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相关论文: Decaying Dark Matter and the Deficit of Dwarf Halo…

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Numerical simulations of Milky-Way size Cold Dark Matter (CDM) halos predict a steeply rising mass function of small dark matter subhalos and a substructure count that greatly outnumbers the observed satellites of the Milky Way. Several…

We used high resolution dark matter only cosmological simulations to investigate the structural properties of Lambda Cold Dark Matter ($\Lambda$CDM) haloes over cosmic time. The haloes in our study range in mass from $\sim 10^{10}$ to $\sim…

宇宙学与河外天体物理 · 物理学 2018-11-28 Silviu M. Udrescu , Aaron A. Dutton , Andrea V. Macciò , Tobias Buck

The shallow faint-end slope of the galaxy mass function is usually reproduced in $\Lambda$CDM galaxy formation models by assuming that the fraction of baryons that turns into stars drops steeply with decreasing halo mass and essentially…

星系天体物理 · 物理学 2018-03-16 Azadeh Fattahi , Julio F. Navarro , Carlos S. Frenk , Kyle Oman , Till Sawala , Matthieu Schaller

We present new cosmological hydrodynamic simulations that incorporate Dark Matter Annihilation Feedback (DMAF), whereby energy released from the annihilation of dark matter particles through decay channels such as photon or…

星系天体物理 · 物理学 2019-02-20 N. Iwanus , P. J. Elahi , F. List , G. F. Lewis

Decaying dark matter (DDM) is a candidate which can solve the discrepancies between predictions of the concordance $\Lambda$CDM model and observations at small scales such as the number counts of companion galaxies of the Milky Way and the…

宇宙学与河外天体物理 · 物理学 2014-07-17 Shohei Aoyama , Toyokazu Sekiguchi , Kiyotomo Ichiki , Naoshi Sugiyama

In the generic CDM cosmogony, dark-matter halos emerge too lumpy and centrally concentrated to host observed galactic disks. Moreover, disks are predicted to be smaller than those observed. We argue that the resolution of these problems may…

天体物理学 · 物理学 2009-10-31 J. Binney , O. Gerhard , J. Silk

We consider models in which a dark-matter particle decays to a slightly less massive daughter particle and a noninteracting massless particle. The decay gives the daughter particle a small velocity kick. Self-gravitating dark-matter halos…

宇宙学与河外天体物理 · 物理学 2010-05-28 Annika H. G. Peter , Christopher E. Moody , Marc Kamionkowski

We study properties of dark matter halos at high redshifts z=2-10 for a vast range of masses with the emphasis on dwarf halos with masses 10^7-10^9 Msun/h. We find that the density profiles of relaxed dwarf halos are well fitted by the NFW…

天体物理学 · 物理学 2009-11-10 P. Colin , A. Klypin , O. Valenzuela , S. Gottlober

We present results from high-resolution N-Body/SPH simulations of rotationally supported dwarf irregular galaxies moving on bound orbits in the massive dark matter halo of the Milky Way.The dwarf models span a range in disk surface density…

We use high resolution Hydro$+$N-Body cosmological simulations to compare the assembly and evolution of a small field dwarf (stellar mass ~ 10$^{6-7}$ M$\odot$, total mass 10$^{10}$ M$\odot$ in $\Lambda$ dominated CDM and 2keV WDM…

The standard cold dark matter (CDM) model has recently been challenged by the claim that dwarf galaxies have dark matter halos with constant density cores. Consequently, numerous alternative dark matter candidates have recently been…

天体物理学 · 物理学 2008-11-26 Frank C. van den Bosch , Rob A. Swaters

We show that dissipationless LCDM simulations predict that the majority of the most massive subhaloes of the Milky Way are too dense to host any of its bright satellites (L_V > 10^5 L_sun). These dark subhaloes have circular velocities at…

宇宙学与河外天体物理 · 物理学 2011-07-11 Michael Boylan-Kolchin , James S. Bullock , Manoj Kaplinghat

Two dimensional calculations of the evolution of remnants generated by the strong mechanical energy deposited by stellar clusters in dwarf galaxies (M \si $10^9 - 10^{10}$ \msun) are presented. The evolution is followed for times longer…

天体物理学 · 物理学 2009-10-30 Sergey A. Silich , Guillermo Tenorio-Tagle

Based on the observed paucity of the dwarf spheroidal (dSph) satellites of the Milky Way at small Galactocentric distances, we put forward the hypothesis that subsequent to the formation of the Milky Way and its satellites, those dSphs that…

天体物理学 · 物理学 2008-11-26 R. Cowsik , Charu Ratnam , Pijushpani Bhattacharjee , Subhabrata Majumdar

We study the formation of dark halos in a $\Lambda$CDM universe under the assumption that Cold Dark Matter particles have a finite cross-section for elastic collisions. We compare evolution when CDM mean free paths are comparable to halo…

天体物理学 · 物理学 2011-07-18 Naoki Yoshida , Volker Springel , Simon D. M. White , Giuseppe Tormen

Context: Dwarf galaxies can arise from self-gravitating structures emerging from tidal tails. What fraction of the known dwarf galaxies in the Local Universe can have this origin is still a matter of debate. Aims: In our effort to…

天体物理学 · 物理学 2009-11-13 S. Recchi , Ch. Theis , P. Kroupa , G. Hensler

The observed luminosity function (LF) of satellite galaxies shows several interesting features that require a better understanding of gas-thermodynamic processes and feedback effects related to reionization and galaxy formation. In galaxy…

天体物理学 · 物理学 2009-11-13 Asantha Cooray , Renyue Cen

The Cold Dark Matter (CDM) theory predicts a wealth of substructure within dark halos. These predictions match observations of galaxy clusters like the nearby Virgo cluster. However, CDM has a "small scale crisis" since galaxies dominate…

天体物理学 · 物理学 2009-11-10 Elena D'Onghia , George Lake

By fitting a flexible stellar anisotropy model to the observed surface brightness and line-of-sight velocity dispersion profiles of Draco we derive a sequence of cosmologically plausible two-component (stars + dark matter) models for this…

天体物理学 · 物理学 2009-11-13 Sergey Mashchenko , Alison Sills , H. M. P. Couchman

The mass and composition of dark matter (DM) particles and the shape and damping scales of the power spectrum of density perturbations can be estimated from recent observations of the DM dominated relaxed objects -- dwarf galaxies and…

宇宙学与河外天体物理 · 物理学 2014-08-22 M. Demianski , A. Doroshkevich