Related papers: Securing Fuel for Our Frigid Cosmic Future
Gas accretion is necessary to maintain star formation, spiral and bar structure, and secular evolution in galaxies. This can occur through tidal interaction, or mass accretion from cosmic filaments. Different processes will be reviewed to…
How much matter is there in the universe? Does the universe have the critical density needed to stop its expansion, or is the universe underweight and destined to expand forever? We show that several independent measures, especially those…
In this paper it is suggested that inclusion of mutual gravitational interactions among the particles in the early dense universe can lead to a 'pre-big bang' scenario, with particle masses greater than the Planck mass implying an…
Recent observations show a large concentration of galaxies at high redshift. At first sight strong clustering of galaxies at high redshifts seems to be in contradiction with the models of structure formation. In this paper we show that such…
Massive quiescent galaxies have much smaller physical sizes at high redshift than today. The strong evolution of galaxy size may be caused by progenitor bias, major and minor mergers, adiabatic expansion, and/or renewed star formation, but…
Star clusters are observed to form in a highly compact state and with low star-formation efficiencies, and only 10 per cent of all clusters appear to survive to middle- and old-dynamical age. If the residual gas is expelled on a dynamical…
Star clusters are observed to form in a highly compact state and with low star-formation efficiencies. If the residual gas is expelled on a dynamical time the clusters disrupt thereby (i) feeding a hot kinematical stellar component into…
Current evidence suggests that the cosmological constant is not zero, or that we live in an open universe. We examine the implications for the future under these assumptions, and find that they are striking. If the Universe is cosmological…
It is shown that the number of members, $N_A$, and the linear radius of the Abell clusters at $z<0.18$ increase with redshift. The increase is caused by observational selection: the number of rich and large clusters is small in the nearby…
In this paper, we focus on ram-pressure stripping and evaporation of disk galaxies in and around a cluster. We show that the evolution of the disk surface density affects the efficiency of ram-pressure stripping of galaxies at z>~1. We also…
In cold dark matter cosmologies, the most massive dark matter halos are predicted to undergo rapid growth at z<1. While there is the expectation that massive galaxies will also rapidly grow via merging, recent observational studies conclude…
There are three major axes to describe the evolution of galaxies, namely, time (redshift), space (environment) and mass (stellar mass). In this article, one topic each will be presented along these axes. (1) Based on the Subaru wide-field…
The properties of old globular cluster systems in galaxy halos are used to infer quantitative constraints on aspects of generic star (cluster) formation. First, the spatial distribution of globulars in three large galaxies, together with…
It is suggested that the recently observed size evolution of very massive compact galaxies in the early universe can be explained, if dark matter is in Bose Einstein condensate. In this model the size of the dark matter halos and galaxies…
The decay of globular clusters to the center of their mother galaxy corresponds to carrying a quantity of mass sufficient to sustain the gravitational activity of a small pre-existing nucleus and to accrete it in a significant way. This is…
According to current theories, tidal interactions between a disk and an embedded planet may lead to the rapid migration of the protoplanet on a timescale shorter than the disk lifetime or estimated planetary formation timescales. Therefore,…
The gas reservoir of galaxies can be altered by outflows driven by star-formation and luminous active galactic nuclei. Jets heating the surroundings of host galaxies can also prevent gas cooling and inflows. Spectacular examples for these…
Gravitational merging (or clustering) of cosmic objects is regarded as a possible source of the extra-acceleration of the universe at large scale. The merging/clustering of cosmic objects introduces a correction term in the equation of…
Globular clusters (GCs) constitute a system which is evolving because of various interactions with the galactic environment. Evolution may be the explanation of many observed features of Globular Cluster Systems (GCSs); the different radial…
Cosmic surveys of large scale structure have imaged hundreds of millions of galaxies and mapped the 3D positions of over a million. Surveys starting over the next few years will increase these numbers more than tenfold. Simultaneously,…