In a previous paper a method was developed to determine the shapes of dark matter halos of spiral galaxies from the flaring and velocity dispersion of the gas layer. Here I present the results for the almost edge-on Scd galaxy NGC 4244 and preliminary results for the Milky Way. NGC 4244’s dark matter halo is found to be highly flattened with a shortest-to-longest axis ratio of 0.2 −0.1 . If the...

Using monolayer graphene as a model system for a purely two-dimensional (2D) electron gas, we show by energy electron loss spectroscopy, highly resolved both in energy and momentum, that there is a significant probability for the excitation of not only one but two dispersing losses. The appearance of both losses is independent of the substrate (we tested graphene on the Si face of 6H-SiC(0001),...

In a previous paper (Olling 1995, AJ, 110, 591) a method was developed to determine the shapes of dark matter halos of spiral galaxies from an accurate determination of the rotation curve, the flaring of the gas layer and the velocity dispersion in the H I . Here this method is applied to the almost edge-on Scd galaxy NGC 4244 for which the necessary parameters are determined in the accompanyin...

The objective of this study is to carry out a parametric sensitivity analysis of PHAST atmospheric dispersion modelling for an accidental toxic gas release scenario. A methodology is developed and is applied to a nitric oxide gas dispersion scenario. We study the relative influence of uncertainty in independent input parameters (storage conditions, atmospheric variables, release parameters and ...

We present analysis of the near-infrared spectra of 114 rest-frame UV-selected star-forming galaxies at z ∼ 2. By combining the Hα spectra with photometric measurements from observed 0.3–8 μm, we assess the relationships between kinematics, dynamical masses, inferred gas fractions, and stellar masses and ages. The Hα line widths give a mean velocity dispersion σ = 101 ± 5 km s and a mean dynami...

Accurate knowledge of molecular diffusion coeffi· cients and their temperature dependence is important in obtaining fundamental information on forces be· tween unlike molecules. Until recently most diffusion measurements were conducted over short temperature intervals because the conventional methods such as the Loschmidt or the Stefan, require the thermostating of large, static systems. Walker...

Wepresent CO(1-0) andCO(2-1) observations of the two nearly face-on galaxies NGC628 and NGC3938, in particular cuts along the major and minor axis. The contribution of the beam-smeared in-plane velocity gradients to the observed velocity width is quite small in the outer parts of the galaxies. This allows us to derive the velocity dispersion of the molecular gas perpendicular to the plane. We f...

Sightlines through high-and intermediate-velocity clouds allow measurements of ionic gas phase abundances, A, at very low values of H I column density, N(H I). Present observations cover over 4 orders of magnitude in N(H I). Remarkably, for several ions we find that the A vs N(H I) relation is the same at high and low column density and that the abundances have a relatively low dispersion (fact...

the analytical theory of one dimensional, dispersion free miscible displacement of oil by injection gas with nc component has shown that: the mmp is the lowest pressure at which any one of the initial oil, injection gas or crossover key tie lines becomes critical, which means that its length approaches to zero. in this paper, we propose a method for a solving multi component system based on ana...

In this paper, we investigated the corrected plasmon dispersion relation for graphene in presence of a constant magnetic field which it includes a quantum term arising from the collective electron density wave interference effects. By using quantum hydrodynamic plasma model which incorporates the important quantum statistical pressure and electron diffraction force, the longitudinal plasmons ar...