Results 51 to 60 of about 601,655 (181)
Can Photoionization Squelching Resolve the Sub-structure Crisis? [PDF]
Astrophys.J.572:L23-L26,2002, 2001 Cold Dark Matter theory predicts that the Local Group should contain many more dwarf-sized objects than the observed number of dwarf galaxies --- the so-called sub-structure problem. We investigate whether the suppression of star formation in these small objects due to the presence of a photoionizing background can resolve the problem.
arxiv +1 more source
Cosmic ray feedback from supernovae in dwarf galaxies [PDF]
Astronomy & Astrophysics, 2020 The regulation of the baryonic content in dwarf galaxies is a long-standing problem. Supernovae (SNe) are supposed to play a key role in forming large-scale galactic winds by removing important amounts of gas from galaxies. SNe are efficient accelerators
G. Dashyan, Y. Dubois
semanticscholar +1 more source
Feedback by Massive Black Holes in Dwarf Galaxies [PDF]
, 2017 Could there be intermediate mass black holes in essentially all old dwarf galaxies? I argue that current observations of Active Galactic Nuclei in dwarfs allow such a radical hypothesis which provides early feedback and potentially provides a unifying explanation for many if not all of the apparent dwarf galaxy anomalies, such as the abundance, core ...
arxiv +1 more source
Limits on the significant mass-loss scenario based on the globular clusters of the Fornax dwarf spheroidal galaxy [PDF]
, 2015 Many of the scenarios proposed to explain the origin of chemically peculiar stars in globular clusters (GCs) require significant mass loss (>= 95 per cent) to explain the observed fraction of such stars. In the GCs of the Fornax dwarf galaxy, significant
P. Khalaj, H. Baumgardt
semanticscholar +1 more source
The coherent motion of Cen A dwarf satellite galaxies remains a challenge for ΛCDM cosmology [PDF]
Astronomy & Astrophysics, 2020 The plane-of-satellites problem is one of the most severe small-scale challenges for the standard Λ cold dark matter (ΛCDM) cosmological model: Several dwarf galaxies around the Milky Way and Andromeda co-orbit in thin, planar structures.
O. Muller +8 more
semanticscholar +1 more source
The dark matter crisis: falsification of the current standard model of cosmology [PDF]
, 2012 The current standard model of cosmology (SMoC) requires The Dual Dwarf Galaxy Theorem to be true according to which two types of dwarf galaxies must exist: primordial dark-matter (DM) dominated (type A) dwarf galaxies, and tidal-dwarf and ram-pressure-dwarf (type B) galaxies void of DM.
arxiv +1 more source
Dwarf Galaxies with Central Cores in Modified Newtonian Dynamics Gravity
Astrophysical Journal, 2022 Some dwarf galaxies are within the Mondian regime at all radii, i.e., the gravitational acceleration provided by the observed baryons is always below the threshold of g † ≃ 1.2 × 10−10 m s−2.
J. Sánchez Almeida
semanticscholar +1 more source
The dynamics of isolated Local Group galaxies [PDF]
2014 MNRAS 439 1015, 2014 We measured velocities of 862 individual red giant stars in seven isolated dwarf galaxies in the Local Group: NGC 6822, IC 1613, VV 124 (UGC 4879), the Pegasus dwarf irregular galaxy (DDO 216), Leo A, Cetus, and Aquarius (DDO 210). We also computed velocity dispersions, taking into account the measurement uncertainties on individual stars.
arxiv +1 more source
The abundance of dwarf galaxies around low-mass giants in the Local Volume [PDF]
A&A 644, A91 (2020), 2020 The abundance of satellite dwarf galaxies has long been considered a crucial test for the current model of cosmology leading to the well-known missing satellite problem. Recent advances in both simulations and observations have allowed to study dwarf galaxies around host galaxies in more detail.
arxiv +1 more source
The Magellanic Group and the Seven Dwarfs [PDF]
, 2008 The Magellanic Clouds were the largest members of a group of dwarf galaxies that entered the Milky Way (MW) halo at late times. This group, dominated by the LMC, contained ~4% of the mass of the Milky Way prior to its accretion and tidal disruption, but ~70% of the known dwarfs orbiting the MW.
arxiv +1 more source