Results 31 to 40 of about 148,135 (75)
Are dwarf spheroidal galaxies dark matter dominated or remnants of disrupted larger satellite galaxies? -- A possible test [PDF]
Astrophys.J. 566 (2002) 838-844, 2001 The failure of standard cosmolocical models in accounting for the statistics of dwarf satellites and the rotation curve of gas-rich dwarf galaxies in detail has led us to examine whether earlier non-equilibrium models of dwarf spheroidal satellites without any dark matter should be reconsidered in more detail.
arxiv +1 more source
The mass of dwarf spheroidal galaxies and the missing satellite problem [PDF]
, 2005 We present the results from a suite of N-body simulations of the tidal stripping of two-component dwarf galaxies comprising some stars and dark matter. We show that recent kinematic data from the local group dwarf spheroidal (dSph) galaxies suggests that dSph galaxies must be sufficiently massive ($10^9 - 10^{10}$M$_\odot$) that tidal stripping is of ...
arxiv +1 more source
Abundance ratios of red giants in low mass ultra faint dwarf spheroidal galaxies [PDF]
A&A 588, A7 (2016), 2015 Low mass dwarf spheroidal galaxies are key objects for our understanding of the chemical evolution of the pristine Universe and the Local Group of galaxies. Abundance ratios in stars of these objects can be used to better understand their star formation and chemical evolution.
arxiv +1 more source
Globular Clusters and Dwarf Spheroidal Galaxies [PDF]
, 2007 Traditionally globular clusters and dwarf spheroidal galaxies have been distinguished by using one or more of the following criteria: (1) mass, (2) luminosity, (3) size, (4) mass-to-light ratio and (5) spread in metallicity. However, a few recently discovered objects show some overlap between the domains in parameter space that are occupied by galaxies
arxiv +1 more source
The effect of gravitational tides on dwarf spheroidal galaxies [PDF]
, 2014 The effect of the local environment on the evolution of dwarf spheroidal galaxies is poorly understood. We have undertaken a suite of simulations to investigate the tidal impact of the Milky Way on the chemodynamical evolution of dwarf spheroidals that resemble present day classical dwarfs using the SPH code GEAR.
arxiv +1 more source
Dwarf spheroidal galaxies and Bose-Einstein condensate dark matter [PDF]
Phys. Rev. D 90, 043517 (2014), 2014 We constrain the parameters of a self-interacting massive dark matter scalar particle in a condensate using the kinematics of the eight brightest dwarf spheroidal satellites of the Milky Way. For the case of a repulsive self-interaction the condensate develops a mass density profile with a characteristic scale radius that is closely related to the ...
arxiv +1 more source
Dark matter distribution and dynamics of dwarf spheroidal galaxies [PDF]
, 2019 I review the current status of dynamical modelling of dwarf spheroidal galaxies focusing on estimates of their dark matter content. Starting with the simplest methods using the velocity dispersion profiles I discuss the inherent issues of mass-anisotropy degeneracy and contamination by unbound stars.
arxiv +1 more source
Dormant dwarf spheroidal galaxies, deactivated by Type Ia supernovae [PDF]
Submitted to The Astrophysical Journal (Letters), 1996 Some dwarf spheroidal galaxies have experienced many Gyrs long periods without star formation. We show that Type Ia supernovae, formed from a first generation of stars, can delay a second epoch of star formation by several Gyrs, if the total gas mass in the dwarf spheroidals is smaller than $10^8 M_{\odot}$.
arxiv +1 more source
Exploring the Evolution of a Dwarf Spheroidal Galaxy with SPH Simulations. II. AGN Feedback
The Astrophysical JournalWe investigate active galactic nucleus (AGN) feedback from an intermediate-mass black hole at the center of a dwarf spheroidal galaxy, by performing isolated galaxy simulations using a modified version of the GADGET-3 code. We consider Leo II (PGC 34176)
Roberto Hazenfratz +3 more
doaj +1 more source
Maximally self-interacting dark matter: models and predictions
Journal of High Energy Physics, 2020 We study self-interacting dark matter (SIDM) scenarios, where the s-wave self-scattering cross section almost saturates the Unitarity bound. Such self-scattering cross sections are singly parameterized by the dark matter mass, and are featured by strong ...
Ayuki Kamada +2 more
doaj +1 more source