Related papers: Missing Mass in Collisional Debris from Galaxies
Debris disks are optically thin, almost gas-free dusty disks observed around a significant fraction of main-sequence stars older than about 10 Myr. Since the circumstellar dust is short-lived, the very existence of these disks is considered…
Minutes into the big bang, nucleosynthesis finds 96 percent of matter nonreactive. Massive pure disk protogalaxies must be formed in the early universe as their galaxies are found at high redshift. Surrounded by hot gas, they made little…
Astronomical observations reveal a gap in the mass spectrum of relativistic objects: neither black holes nor neutron stars with 2 - 5 solar masses have ever been observed. In this article I proceed in presenting the scenario which discloses…
The dynamics of the merger of a dwarf disc galaxy with a massive spiral galaxy of the Milky Way type have been studied in detail. The remnant of such interaction after numerous crossings of the satellite through the disc of the main galaxy…
Recent observations on structural properties of the Large Magellanic Cloud (LMC) based on the Deep Near-Infrared Southern Sky Survey (DENIS) and Two Micron All-Sky Survey (2MASS) have revealed that the LMC has an off-center bar even in the…
Starting from the 1970s, some relations connecting dark matter and baryons were discovered, such as the Tully-Fisher relation. However, many of the relations found in galaxies are quite different from that found in galaxy clusters. Here, we…
Growing evidence has been accumulated for that some gas-rich dwarf galaxies are formed from material liberated by galaxy collisions and/or mergers. Also, gas-poor dwarf elliptical galaxies are often found in the central regions of clusters…
Possible observational consequences of dark matter in the Galaxy in the form of dense molecular gas clouds - clumpuscules of masses $M_c\sim 10^{-3} \msun$ and radii $R_c\sim 3\times 10^{13}$ cm - are considered. Recent models of the…
Approximately half of the Universe's dark matter resides in collapsed halos; significantly less than half of the baryonic matter (protons and neutrons) remains confined to halos. A small fraction of baryons are in stars and the interstellar…
Galaxies are biased tracers of the underlying cosmic web, which is dominated by dark matter components that cannot be directly observed. The relationship between dark matter density fields and galaxy distributions can be sensitive to…
We examine the gas content of field dwarf galaxies in a high-resolution cosmological simulation. In agreement with previous work, we find that galaxies inhabiting dark matter haloes with mass below a critical value, $M_{200} \lesssim M_{\rm…
New simulations are presented which investigate the formation of smaller groups of galaxies in a CDM like universe. The simulations follow the evolution of dark matter and gas and are performed with an SPH code adapted for the…
It has been proposed that mergers induce starbursts and lead to important morphological changes in galaxies. Most studies so far have focused on large galaxies, but dwarfs might also experience such events, since the halo mass function is…
We propose experimental schemes for detection an axionic condensate supposed to be cosmic dark matter. Various procedures are considered in dependence on the value of the axion mass. There are well known indications that a large part of the…
A surprisingly large number of galaxies with masses of $\sim10^9-10^{10}M_\odot$ at redshifts of $z\geq9$ are discovered with the James Webb Space Telescope. A possible explanation for the increase in the mass function can be the presence…
The recently observed Deuterium abundance in a low- metallicity high-redshift hydrogen cloud, which is about ten times larger than that observed in the near interstellar medium, is that expected from the Standard Big Bang Nucleosynthesis…
The observed excess of gravitational forces in galaxies and galactic clusters is usually referred as the existence of "dark matter particles" of unknown origin. An alternative explanation of the dark matter effect is presented here by…
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…
The existence of macroscopic regions with antibaryon excess in the baryon asymmetric Universe with general baryon excess is the possible consequence of practically all models of baryosynthesis. Diffusion of matter and antimatter to the…
The observed tightness of the mass discrepancy-acceleration relation (MDAR) poses a fine-tuning challenge to current models of galaxy formation. We propose that this relation could arise from collisional interactions between baryons and…