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Related papers: The cusp-core problem in gas-poor dwarf spheroidal…

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The cusp-core problem is one of the main challenges of the cold dark matter paradigm on small scales: the density of a dark matter halo is predicted to rise rapidly toward the center as rho ~ r^alpha with alpha between -1 and -1.5, while…

Astrophysics of Galaxies · Physics 2021-03-10 Yong Shi , Zhi-Yu Zhang , Junzhi Wang , Jianhang Chen , Qiusheng Gu , Xiaoling Yu , Songlin Li

We use $\Lambda$CDM cosmological hydrodynamical simulations to explore the kinematics of gaseous discs in late-type dwarf galaxies. We create high-resolution 21-cm 'observations' of simulated dwarfs produced in two variations of the EAGLE…

We study the distribution of dark matter in dwarf spheroidal galaxies by modelling the moments of their line-of-sight velocity distributions. We discuss different dark matter density profiles, both cuspy and possessing flat density cores.…

Astrophysics · Physics 2009-11-07 Ewa L. Lokas

The rotation curves of some star forming massive galaxies at redshift two decline over the radial range of a few times the effective radius, indicating a significant deficit of dark matter (DM) mass in the galaxy centre. The DM mass deficit…

Astrophysics of Galaxies · Physics 2022-06-15 Go Ogiya , Daisuke Nagai

A promising proposal for resolving the cusp-core anomaly in the density profile of dwarf galaxies is to allow dark matter to interact with itself through a light mediator of mass much less than a GeV. The theoretical challenge is to have a…

High Energy Physics - Phenomenology · Physics 2017-02-22 Ernest Ma

We make a direct comparison of the derived dark matter (DM) distributions between hydrodynamical simulations of dwarf galaxies assuming a LCDM cosmology and the observed dwarf galaxies sample from the THINGS survey in terms of (1) the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Se-Heon Oh , Chris Brook , Fabio Governato , Elias Brinks , Lucio Mayer , W. J. G. de Blok , Alyson Brooks , Fabian Walter

For almost two decades the properties of "dwarf" galaxies have challenged the Cold Dark Matter (CDM) paradigm of galaxy formation. Most observed dwarf galaxies consists of a rotating stellar disc embedded in a massive DM halo with a near…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Fabio Governato , Chris Brook , Lucio Mayer , Alyson Brooks , George Rhee , James Wadsley , Patrik Jonsson , Beth Willman , Greg Stinson , Thomas Quinn , Piero Madau

We propose and successfully test against new cosmological simulations a novel analytical description of the physical processes associated with the origin of cored dark matter density profiles. In the simulations, the potential in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Andrew Pontzen , Fabio Governato

Measurements of the rotation curves of dwarf galaxies are often interpreted as requiring a constant density core at the centre, at odds with the "cuspy" inner profiles predicted by $N$-body simulations of cold dark matter (CDM) haloes. It…

This study investigates the dynamical response of dark matter (DM) halos to recurrent starbursts in forming less-massive galaxies to solve the core-cusp problem. The gas, which is heated by supernova feedback after a starburst, expands and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Go Ogiya , Masao Mori

Recent observations indicate that dark matter haloes have flat central density profiles. Cosmological simulations with non-baryonic dark matter predict however self similar haloes with central density cusps. This contradiction has lead to…

Astrophysics · Physics 2009-10-28 A. Burkert

Dwarf galaxies pose significant challenges for cosmological models. In particular, current models predict a dark matter density that is divergent at the center, in sharp contrast with observations which indicate an approximately constant…

Astrophysics · Physics 2009-11-13 Sergey Mashchenko , James Wadsley , H. M. P. Couchman

A number of dwarf spheroidal (dSph) galaxies are known to contain a more extended, metal-poor population with a flattish velocity dispersion profile, and a more concentrated, metal-rich population with a velocity dispersion declining with…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 N. C. Amorisco , N. W. Evans

One of the predictions of the standard CDM is that dark haloes have centrally divergent density profiles. An extensive body of rotation curve observations of dwarf and low surface brightness galaxies shows the dark haloes of those systems…

Astrophysics · Physics 2009-10-31 C. Firmani , E. D'Onghia , G. Chincarini , X. Hernandez , V. Avila-Reese

We use cosmological hydrodynamical simulations of the APOSTLE project along with high-quality rotation curve observations to examine the fraction of baryons in {\Lambda}CDM haloes that collect into galaxies. This 'galaxy formation…

Using deep HST/ACS observations of the core of the Perseus Cluster, we identify a large population of dwarf elliptical galaxies down to M_V = -12. All these dwarfs are remarkably smooth in appearance, showing no evidence for internal…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Samantha J. Penny , Christopher J. Conselice , Sven De Rijcke , Enrico V. Held

We speculate that the dark halos of dwarf galaxies and low surface brightness galaxies soften their central cusps by the decay of a fraction of cold dark matter (CDM) particles to a stable particle with a recoiling velocity of a few tens km…

Astrophysics · Physics 2011-08-23 F. J. Sanchez-Salcedo

We examine the circular velocity profiles of galaxies in {\Lambda}CDM cosmological hydrodynamical simulations from the EAGLE and LOCAL GROUPS projects and compare them with a compilation of observed rotation curves of galaxies spanning a…

Formation and disruption of dark-matter cusps are reviewed. Accumulation of baryons at the center of a halo can displace the dark matter, converting singular density cusps into low-density cores. The displaced mass can be of order 10 M_b…

Astrophysics · Physics 2007-05-23 David Merritt , Milos Milosavljevic

Dwarf spheroidal galaxies have shallow central dark matter density profiles, low angular momentum and approximately exponential surface brightness distributions. Through N-body simulations and analytic calculations we investigate the extent…

Astrophysics · Physics 2009-11-10 J. I. Read , G. Gilmore