Related papers: On the Energy Required to Eject Processed Matter f…
We show that the gas in growing density perturbations is vulnerable to the influence of winds outflowing from nearby collapsed galaxies that have already formed stars. This suggests that the formation of nearby galaxies with masses less…
Strong bursts of star formation in galaxies may be triggered either by internal or external mechanisms. We study the distribution and kinematics of the HI gas in the outer regions of 18 nearby starburst dwarf galaxies, that have accurate…
Optical/UV photons and even harder radiation components in galaxies are absorbed and scattered by dust and re-emitted at infrared wavelengths. For a better understanding of the obscured regions of the galaxies detailed models of the…
Cosmic ray protons interacting with gas at the mean density of the interstellar medium in starburst galaxies lose energy rapidly via inelastic collisions with ambient nuclei. The resulting pions produce secondary electrons and positrons,…
The common approach to compute the cosmic-ray distribution in an starburst galaxy or region is equivalent to assume that at any point within that environment, there is an accelerator inputing cosmic rays at a reduced rate. This rate should…
The surface brightness distribution in the majority of stellar galactic discs falls off exponentially. Often what lies beyond such a stellar disc is the neutral hydrogen gas whose distribution also follows a nearly exponential profile at…
We investigate large-scale galactic winds driven by momentum deposition. Momentum injection is provided by (1) radiation pressure produced by the continuum absorption and scattering of UV photons on dust grains and (2) supernovae. UV…
We argue that any violent galactic winds following early epoch of star bursts would significantly weaken the potentials of galaxies, and leave lasting signatures such as a lowered dark halo density and preferentially radial/escaping orbits…
The fate of ionizing radiation is vital for understanding cosmic ionization, energy budgets in the interstellar and intergalactic medium, and star formation rate indicators. The low observed escape fractions of ionizing radiation have not…
Evidence for the accretion of cold gas in galaxies has been rapidly accumulating in the past years. HI observations of galaxies and their environment have brought to light new facts and phenomena which are evidence of ongoing or recent…
In this work we present a semi-analytical model of galactic wind for dwarf galaxies where thermal and turbulent/momemtum driving mechanisms are studied. The model takes into account wave and internal adiabatic heating mechanisms, as well as…
The interaction of galaxies with their environment, the Intergalactic Medium (IGM), is an important aspect of galaxy formation. One of the most fundamental, but unanswered questions in the evolution of galaxies is how gas circulates in and…
Using a sample of nearly half a million galaxies, intersected by over 8 million lines of sight from the Sloan Digital Sky Survey Data Release 12, we extend our previous study of the recombination radiation emitted by the gaseous halos of…
Observations over the past decade have verified, beyond reasonable doubt, that most galactic nuclei contain massive black holes. Hole masses are being measured and firm evidence for spin is being sought. Attention is now returning to the…
This paper shows that gravitating bodies travelling through the Galaxy can trap lighter interstellar particles that pass nearby with small relative velocities onto temporarily-bound orbits. The capture mechanism is driven by the Galactic…
With a goal toward deriving the physical conditions in external galaxies, we present a survey of the formaldehyde emission in a sample of starburst systems. By extending a technique used to derive the spatial density in star formation…
The under-abundance of very massive galaxies in the universe is frequently attributed to the effect of galactic winds. Although ionized galactic winds are readily observable most of the expelled mass is likely in cooler atomic and molecular…
We present numerical simulations of the dynamical and chemical evolution of galaxy clusters. X-ray spectra show that the intra-cluster medium contains a significant amount of metals. As heavy elements are produced in the stars of galaxies…
We review the origin and structure of hot (cooling flow) gas in elliptical galaxies. X-ray observations can be used to determine the stellar mass to light ratio, the mass profiles of dark matter halos, and the interstellar magnetic field.…
We investigate the dependence of star formation and the distribution of the components of galaxies on the strength of ram pressure. Several mock observations in X-ray, H$\alpha$ and HI wavelength for different ram-pressure scenarios are…