Related papers: Feedback by Massive Black Holes in Dwarf Galaxies
We consider the contribution of neutron stars and black holes to the dynamical mass of galactic halos. In particular, we show that if these compact objects were produced by an early generation of stars with initial metallicity less than…
Black holes with hundreds to thousands of solar masses are more massive than can be formed from a single star in the current universe, yet the best candidates for these objects are not located in gas-rich environments where gradual…
Recent studies have established that extreme dwarf galaxies --whether satellites or field objects-- suffer from the so called "too big to fail" (TBTF) problem. Put simply, the TBTF problem consists of the fact that it is difficult to…
A number of so-called ultra-cool white dwarfs have been detected in different surveys so far. However, based on anecdotal evidence it is believed that most or all of these ultra-cool white dwarfs are low-mass products of binary evolution…
Impulsive supernova feedback and non-standard dark matter models, such as self-interacting dark matter (SIDM), are the two main contenders for the role of the dominant core formation mechanism at the dwarf galaxy scale. Here we show that…
We explore the potential cumulative energy production of stellar mass black holes in early galaxies. Stellar mass black holes may accrete substantially from the higher density interstellar media of primordial galaxies, and their energy…
We review numerous arguments for primordial black holes (PBHs) based on observational evidence from a variety of lensing, dynamical, accretion and gravitational-wave effects. This represents a shift from the usual emphasis on PBH…
I review the observational side of the present state of the debate about the dark matter in galaxies, with emphasis on the core/cusp problem in low surface brightness galaxies, and the question of maximum / sub-maximum disks in spiral…
The mere existence of multiple stellar generations in Milky Way globular clusters indicates that each generation was unable to stop star formation, that instead persisted unimpeded for several million years. This evidence argues for an…
Observations of the cosmic microwave background constrain the abundance of primordial black holes, as these would accrete gas and inject energy into the cosmological medium. We have revisited these constraints, taking into account the local…
Experiments are looking for diffuse brown dwarfs in the dark galactic halo through the gravitational lens effect. If brown dwarfs are clumped in dark clusters, the event rate is not changed, but events are spatially clustered, and stars…
We present a new model for the formation of stellar halos in dwarf galaxies. We demonstrate that the stars and star clusters that form naturally in the inner regions of dwarfs are expected to migrate from the gas rich, star forming centre…
The possibility that primordial black hole binary mergers of stellar mass can explain the signals detected by the gravitational-wave interferometers has attracted much attention. In this scenario, primordial black holes can comprise only…
Supernova and multiple supernova events regulate several structural properties of dwarf galaxies. In particular, they govern the metal enrichment and the energy budget of the ISM; they might induce partial (blowout) or total (blowaway) gas…
After summarizing the characteristics of different types of dwarf galaxies I briefly review our current state of knowledge of dwarf galaxy evolution in the Local Group, for which we now have a fairly detailed although by no means…
Cosmological simulations of the $\Lambda$CDM model suggest that the dark matter halos of dwarf galaxies are denser in their center than what observational data of such galaxies imply. In this letter, we propose a novel solution to this…
Recently the problem of singular galactic cores and over-abundant formation of dwarf galaxies, inherent to the standard cold dark matter model, had attracted a great deal of attention. One scenario which may be free of these problems…
The microlensing experiments in the direction of the LMC seem to be indicating that about 60% of the dark matter in the Galactic halo is tied up in objects whose masses are about half the mass of the Sun. This mass is a natural one for old…
Ultra compact dwarf galaxies (UCDs) have similar properties as massive globular clusters or the nuclei of nucleated galaxies. Recent observations suggesting a high dark matter content and a steep spatial distribution within groups and…
By analyzing data from DESI Legacy Imaging Survey of the dwarf galaxies in the Arecibo Legacy Fast Alfa Survey, we have identified five ultra-diffuse galaxies (UDGs) featuring central pseudo-bulges. These UDGs display blue pseudo-bulges…