Related papers: Possible origin of Larson's lows

In the cold dark matter scenario, dark matter halos are assembled hierarchically from smaller subunits. Some of these subunits are disrupted during the merging process, whereas others survive temporarily in the form of subhalos. A…

In the context of the standard model of particle physics, there is a definite upper limit to the density of stable compact stars. However, if there is a deeper layer of constituents, below that of quarks and leptons, stability may be…

A standard paradigm is now available for the recent evolution (z < 10) of structure on galactic and larger scales. Most of the matter is assumed to be dark and dissipationless and to cluster hierarchically from gaussian initial conditions.…

The gravitational lensing constraints on the small mass end of the LCDM mass function are discussed. Here a conservative approach is taken where only the most difficult to explain image flux anomalies in strong QSO lenses are emphasized.…

There are compelling reasons to believe that the dark matter of the universe is constituted, in large part, by non-baryonic collisionless particles with very small primordial velocity dispersion. Such particles are called cold dark matter…

We discuss two slightly counter-intuitive findings about the environmental dependence of clustering in the Sloan Digital Sky Survey. First, we find that the relation between clustering strength and density is not monotonic: galaxies in the…

The most recent observational evidence seems to indicate that giant molecular clouds are predominantly gravitationally unbound objects. In this paper we show that this is a natural consequence of a scenario in which cloud-cloud collisions…

Low-mass stars are generally understood to form by the gravitational collapse of the dense molecular clouds known as starless cores. Continuum observations have not been able to distinguish among the several different hypotheses that…

Observations of density profiles of galaxies and clusters constrain the properties of dark matter. Formation of stable halos by collisional fluids with very low mass particles appears as the most probable interpretation, while halos formed…

Stars form within molecular clouds, so characterizing the physical states of molecular clouds is key in understanding the process of star formation. Cloud structure and stability is frequently assessed using metrics including the virial…

Galaxy clusters show large-scale azimuthal X-ray surface brightness fluctuations known as cold fronts. Cold fronts are argued to originate due to sloshing driven by sub-halo passage at close proximity to the cluster center. While this…

For about two decades, a population of relative small and nearby molecular clouds has been known to exist at high Galactic latitudes. Lying more than 10$^\circ$ from the Galactic plane, these clouds have typical distances of $\sim$150 pc,…

It is generally thought that galaxies are embedded in dark matter halos extending well beyond their luminous matter. The existence of these galactic halos is mainly derived from the larger than expected velocities of stars and gas in the…

Clouds containing molecular dark matter in quantities relevant for star formation may exist in minihaloes of the type of cold dark matter included in many cosmological simulations or in the regions of some galaxies extending far beyond…

A simple consistency argument for hypothesis of the galactic halo origin of the Ly-alpha forest absorption lines is advanced, based on the recent determination of column-density vs. impact parameter relation for the low-redshift gaseous…

By means of high-resolution N-body simulations in a LambdaCDM cosmology, we verify that scaling relations similar to those observed for nearby galaxy clusters are also defined by their dark matter hosts; the slopes, however, are not the…

Giant molecular clouds (GMCs) are the major reservoirs of molecular gas in galaxies, and the starting point for star formation. As such, their properties play a key role in setting the initial conditions for the formation of stars. We…

Recent observations suggest appreciable star formation activity in early-type galaxies down to redshift $z\sim 0.5$. If so, there is likely to be dust in these galaxies. We consider the possibility that obscuration by dust can reconcile the…

It is now, generally, believed that the presence of some form of dark matter is essential to explain the flat rotation curves of galaxies, and anomalous large velocities of galaxies in the clusters and superclusters. This dark matter turns…

Observed rotational curves of neutral hydrogen clouds strongly support the fact that galactic halo contains huge amount of nonluminous matter, the so called gravitational dark matter. The nature of dark matter is a point of debate among the…