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...

Under very general assumptions we show that the quark dispersion relation in the quark-gluon plasma is given by two collective branches, of which one has a minimum at a nonvanishing momentum. This general feature of the quark dispersion relation leads to structures (van Hove singularities, gaps) in the low mass dilepton production rate, which might provide a unique signature for the quark-gluon...

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...

Heavy ion injection events (registered in the C+/N+/O+ mass channel) into the ionosphere at 1700 km height are surveyed using the Swedish-German Freja satellite data. Heavy ion injections from the inner magnetosphere are mostly found in the nightside sector with a few exceptions that occur on the dayside. We report on these exceptional cases, particularly two specific events which seem to have ...

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...

This paper reports that bursty hot spot sizes are a key factor in causing the heavy-tail distribution of flights in human walks. A heavy-tailed distribution of flights is a signature feature of Levy walks. The data analysis based on GPS traces of human walks reveals that the sizes of a few extremely large hot spots are dominating the mean size of hot spots and they cause the bursty (i.e., long-...

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...

In the present work, the use of nano-metallic calcium (Ca) and calcium oxide (CaO) dispersion mixture for the immobilization of heavy metals (As, Cd, Cr and Pb) in soil was investigated. With simple grinding, 85-90% of heavy metals immobilization could be achieved, while it could be enhanced to 98-100% by grinding with the addition of nano-metallic Ca/CaO dispersion mixture. By SEM-EDS elementa...