Related papers: Hydrodynamics, Vortices and Angular Momenta of Cel…
Galactic accretion interacts in complex ways with gaseous halos, including galactic winds. As a result, observational diagnostics typically probe a range of intertwined physical phenomena. Because of this complexity, cosmological…
Spirals in galaxies have long been thought to be caused by gravitational instability in the stellar component of the disk, but discerning the precise mechanism had proved elusive. Tidal interactions, and perhaps bars, may provoke some…
The angular momentum of galaxies controls the kinematics of their stars, which in turn drives observable quantities such as the apparent radius, the bulge fraction, and the alignment with other nearby structures. To show how angular…
We consider a cosmological setting for which the currently expanding era is preceded by a contracting phase, that is, we assume the Universe experienced at least one bounce. We show that scalar hydrodynamic perturbations lead to a singular…
Young, massive star clusters are the most notable and significant end products of violent star-forming episodes triggered by galaxy collisions, mergers, and close encounters. Their contribution to the total luminosity induced by such…
Determining how galaxies accumulate stellar mass is paramount to understanding the Universe. Two primary mechanisms drive this process: star-formation (SF) & mergers. Our understanding of star formation, and to some degree the processes…
[Abridged] Star and planet formation are the complex outcomes of gravitational collapse and angular momentum transport mediated by protostellar and protoplanetary disks. In this review we focus on the role of gravitational instability in…
Recent observations have revealed the presence of a variety of small-scale ``micro-structures'' in Planetary Nebulae images. I discuss numerical hydrodynamics models of planetaries and outline the formation and growth of instabilities that…
Evidence is summarized that suggests that when a protogalaxy collapses, a fraction $f$ of its gas fails to heat to the virial temperature, where $f$ is large for haloes less massive than the value $M^*$ associated with $L^*$ galaxies. Stars…
A rational theory is proposed to describe the large-scale motion in turbulence. The fluid element with inner orientational structures is proposed to be the building block of fluid dynamics. The variance of the orientational structures then…
A typical galaxy consists of a huge number of stars attracted to each other by gravity. For instance, the Milky Way has about $10^{11}$ stars. Thus it is typically modeled by the Vlasov-Poisson system. We prove an existence theorem for…
The traditional view of the morphology-spin connection is being challenged by recent integral-field-unit observations, as the majority of early-type galaxies are found to have a rotational component that is often as large as a dispersion…
Astrophysical fluid bodies that orbit close to one another induce tidal distortions and flows that are subject to dissipative processes. The spin and orbital motions undergo a coupled evolution over astronomical timescales, which is…
We introduce a new model for the structure and evolution of the gas in galactic discs. In the model the gas is in vertical pressure and energy balance. Star formation feedback injects energy and momentum, and non-axisymmetric torques…
Star formation is one of the least understood processes in cosmic evolution. It is difficult to formulate a general theory for star formation in part because of the wide range of physical processes involved. The interstellar gas out of…
Pinning of superfluid vortices to the nuclear lattice of the inner crust of a neutron star supports a velocity difference between the superfluid and the solid as the star spins down. Under the Magnus force that arises on the vortex lattice,…
Their ubiquity and extreme densities make star clusters probes of prime importance of galaxy evolution. Old globular clusters keep imprints of the physical conditions of their assembly in the early Universe, and younger stellar objects,…
Star formation is intimately linked to the dynamical evolution of molecular clouds. Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud…
We reconstruct the history of the cosmic star formation as well as the cosmic production of metals in the universe by means of detailed chemical evolution models for galaxies of different morphological types. We consider a picture of…
There is growing evidence for star formation inside outflows of active galactic nuclei (AGNs). The formed stars are injected into bulges and give rise to perturbation of bulges. In this paper, we investigate the issues of non-rotating,…