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The environments of supernova explosions are often inhomogeneous, and there may be jumps in their density structure. We have developed a semianalytic model under the thin-shell approximation for super...
High-Density Molecular Gas in the Infrared-bright Galaxy System VV 114
kinematics and dynamics VV 114
2014/12/24
The new high-resolution CO (3-2) interferometric map of the IR-bright interacting galaxy system VV 114 observed with the Submillimeter Array reveals a substantial amount of warm and dense gas in the I...
Supernova Blast Waves in Low-Density Hot Media: A Mechanism for Spatially Distributed Heating
structure supernova remnants
2014/12/24
Most supernovae are expected to explode in low-density hot media, particularly in galactic bulges and elliptical galaxies. The remnants of such supernovae, although difficult to detect individually, c...
On the origin of cold dark matter halo density profiles
dark matter large-scale structure of the universe
2014/12/24
N-body simulations predict that cold dark matter (CDM) halo-assembly occurs in two phases: (i) a fast-accretion phase with a rapidly deepening potential well; and (ii) a slow-accretion phase character...
LINEAR POLARIZATION AND TOTAL FLUX DENSITY OF SILICON MONOXIDE MASERS AND ACTIVE EXTRAGALACTIC OBJECTS AT MILLIMETER WAVELENGTHS
Millimeter-wave wireless resources Linear polarization Radio astronomy observatory telescope Maser The Milky Way
2014/12/10
In order to investigate the linear polarization properties of millimeter-wave radio sources, a polarimeter was constructed for use on the Five College Radio Astronomy Observatory 14m telescope. Linear...
Evidence for top-heavy stellar initial mass functions with increasing density and decreasing metallicity
formation mass-functionlatetype globular clusters general top-heavy stellar metallicity
2012/2/23
Residual-gas expulsion after cluster formation has recently been shown to leave an imprint in the low-mass present-day stellar mass function (PDMF) which allowed the estimation of birth conditions of ...
A Density Independent Formulation of Smoothed Particle Hydrodynamics
Density Independent Formulation Smoothed Particle Hydrodynamics Cosmology and Extragalactic Astrophysics
2012/2/21
In the standard formulation of the smoothed particle hydrodynamics (SPH), it is assumed that the local density distribution is differentiable. This assumption is used to derive the spatial derivatives...
Flux density measurements of a complete sample of faint blazars
fl ux density spectral index polarisation – galaxies quasars BL Lacs radio continuum galaxies
2011/10/18
We performed observations with the Effelsberg 100-m radio telescope to measure flux densities and polarised emission of sources selected from the "Deep X-ray Radio Blazar Survey" (DXRBS) to better def...
Constraints from the CMB temperature and other common observational data-sets on variable dark energy density models
Cosmology Dark energy Thermodynamics
2011/10/13
The thermodynamic and dynamical properties of a variable dark energy model with density scaling as rho_x \propto (1+z)^m, z being the redshift, are discussed following the outline of Jetzer et al. Thi...
The Turbulence Spectrum of Molecular Clouds in the Galactic Ring Survey: A Density-Dependent PCA Calibration
Turbulence Spectrum Molecular Clouds Galactic Ring Survey
2011/10/13
Turbulence plays a major role in the formation and evolution of molecular clouds. The problem is that turbulent velocities are convolved with the density of an observed region. To correct for this con...
An HI column density threshold for cold gas formation in the Galaxy
column density threshold cold gas formation Galaxy
2011/9/28
We report the discovery of a threshold in the HI column density of Galactic gas clouds below which the formation of the cold phase of HI is inhibited. This threshold is at $N_{HI} = 2 \times 10^{20}$ ...
Gas density and star formation in the rarified regions of discs of normal and LSB galaxies
Gas density star formation rarified regions discs normal
2011/10/11
We calculated the radial profiles of the azimuthally averaged midplane gas volume density $\rho_g$ for 11 high surface brightness (HSB) spiral galaxies, 7 low surface brightness (LSB) galaxies and 3 S...
Magnetic Energy Storage and Current Density Distributions for Different Force-Free Models
Magnetic fi elds Corona - Active Regions Structure - Electric Cur- rents Current Sheets
2011/10/10
The change in the magnetic configuration due to the increase/decrease of electric current for different force-free models (potential, linear and nonlinear force-free fields) has never been studied in ...
Gravitationally Induced Density Wake of a Circularly Orbiting Object As an Interpretative Framework of Ubiquitous Spirals and Arcs
Induced Density Circularly Orbiting Interpretative Framework Ubiquitous Spirals
2011/10/9
An orbiting object in a gas rich environment creates a gravitational density wake containing information about the object and its orbit. Using linear perturbation theory, we analyze the observable pro...
A Model for the Origin of High Density in Loop-top X-ray Sources
Model Origin Density Loop-top X-ray Sources
2011/10/8
Super-hot looptop sources, detected in some large solar flares, are compact sources of HXR emission with spectra matching thermal electron populations exceeding 30 megakelvins. High observed emission ...