THE ROLL-OVER OF HELIOSPHERIC NEUTRAL HYDROGEN BELOW 100 eV: OBSERVATIONS AND IMPLICATIONS

Variation of bulk velocity and temperature anisotropy of neutral heliospheric hydrogen during the solar cycle

Using a time-dependent kinetic approach the density, bulk velocity vector, and temperature tensor of interstellar hydrogen in the inner Solar System in several phases of solar cycle were computed. Model solar cycle time-profiles of hydrogen ionisation rate and Lyman-α radiation pressure were used, solar latiudinal effects and filtration at the heliospheric interface were neglected. It was concl...

Observations of Neutral Hydrogen in the Milky Way

Concatenation of Scales Below 1 eV ∗

There are (at least) four numbers of physical and cosmological significance, whose inferred values, when expressed in mass units, cluster in a window below 1 eV. There are: the neutrino mass, the neutrino chemical potential, the cosmological constant, and the size of two extra dimensions (if the fundamental scale of gravity is 1−10 TeV). In this note, we imagine ways in which these four numbers...

The Heliospheric Hydrogen Distribution: a Multifluid Model

We investigate the self-consistent interaction of the local interstellar cloud (LIC) and solar wind, focusing on its manifestations in the heliospheric hydrogen (H) distribution. This system is modeled hydrodynamically as a Ñuid proton-electron plasma and three H Ñuids, each arising from charge exchange production within three distinct plasma environments. Perhaps our most signiÐcant Ðnding is ...

Calibration of distorted wave Born approximation for electron impact excitation of Ne and Ar at incident energies below 100 eV

Abstract We calibrate the distorted wave Born approximation (DWBA) for electron impact excitation processes empirically. Differential cross sections (DCSs) for the excitation of the 2p53s, 2p53p, 2p54s and 2p54p configurations of Ne and the 3p54s and 3p54p configurations of Ar by electron impact are calculated using DWBA for incident energies between 20 and 100 eV. The calculated results are co...