Charge exchange ionization rate of interplanetary hydrogen atoms and Lyman α intensity pattern in the inflow direction of the interstellar gas

2001 ◽  
pp. 133-136 ◽  
Author(s):  
T. Summanen ◽  
T. Mäkinen ◽  
E. Kyrölä ◽  
W. Schmidt
Keyword(s):  
Charge Exchange ◽  
Ionization Rate ◽  
Hydrogen Atoms ◽  
Interstellar Gas ◽  
Intensity Pattern ◽  
Charge Exchange Ionization

Low energetic Interstellar hydrogen atoms in the heliosphere: Decade of IBEX observations

2020 ◽  
Author(s):  
Olga Katushkina ◽  
Vladislav Izmodenov ◽  
André Galli
Keyword(s):  
Charge Exchange ◽  
Signal To Noise Ratio ◽  
Velocity Distribution Function ◽  
Solar Radiation Pressure ◽  
Ionization Rate ◽  
Temporal Variations ◽  
Model Parameters ◽  
Hydrogen Distribution ◽  
Hydrogen Atoms ◽  
Parametric Search

<p>This work is devoted to the analysis of the interstellar hydrogen fluxes measured by IBEX spacecraft from 2009 to 2018. To calculate the fluxes we use our 3D time-dependent kinetic model of the hydrogen distribution in the heliosphere that takes into account non-maxwellian behavior of the velocity distribution function of hydrogen atoms due to charge exchange with protons at the heliospheric boundary. The temporal variations of the hydrogen fluxes during the entire solar cycle are considered and analyzed by comparison of the IBEX-Lo data and the model results. During solar maximum the measured fluxes are too low, therefore we choose several years 2009-2011 and 2017-2018 when the signal-to-noise ratio is appropriate. A parametric search is performed to determine the influence of different model parameters on the full sky maps of the fluxes. It is found that solar radiation pressure is the most crucial parameter for the position of the maximum fluxes, while the heliolatitudinal variations of the charge exchange ionization rate influence the shape of the maps during solar minimum conditions. The quantitative differences between the data and the model results are demonstrated, and several possible reasons for them are discussed.</p>

Remarks on the diffuse interstellar lines

1967 ◽  
Vol 31 ◽  
pp. 91-93 ◽  
Author(s):  
G. Herzberg
Keyword(s):  
Hydrogen Atoms ◽  
Interstellar Gas

It is suggested that the diffuse interstellar lines are produced in the interstellar gas by molecules consisting of a few hydrogen atoms and one other atom, such as CH4+ or NH4. Diffuseness of the lines is assumed to result from predissociation of these molecules.

scholarly journals Model Calculations of Solar Wind Expansion Including an Enhanced Fraction of Ionizing Electrons

1980 ◽  
Vol 91 ◽  
pp. 159-162
Author(s):  
E. F. Petelski ◽  
H. J. Fahr ◽  
H. W. Ripken
Keyword(s):  
Solar Wind ◽  
Impact Ionization ◽  
Hydrogen Atoms ◽  
Interstellar Gas ◽  
Model Calculations ◽  
Neutral Gas ◽  
Continuity Equations ◽  
Velocity Effect ◽  
Collective Interactions ◽  
Ionization Velocity

Collective interactions of the solar wind and newly ionized interstellar gas cause turbulent electron heating to ionizing energies analogous to laboratory experiments on the critical ionization velocity effect. Implications for solar wind and interstellar gas dynamics are calculated by simultaneously solving continuity equations for solar wind protons, interstellar hydrogen atoms, and energetic electrons. Electron impact ionization is shown to be practically as important as photoionization, giving rise to a stronger deceleration and heating of the distant solar wind, a weaker terminating shock, a smaller stand-off distance of the helio pause, and implying higher densities of the outer solar wind and the interstellar neutral gas.

scholarly journals Hydride spectroscopy of the diffuse interstellar medium: new clues on the gas fraction in molecular form and cosmic ray ionization rate in relation to H 3 +

2012 ◽  
Vol 370 (1978) ◽  
pp. 5174-5185 ◽  
Author(s):  
M. Gerin ◽  
F. Levrier ◽  
E. Falgarone ◽  
B. Godard ◽  
P. Hennebelle ◽  
...  
Keyword(s):  
Molecular Form ◽  
Chemical Properties ◽  
Cosmic Ray ◽  
Building Blocks ◽  
Ionization Rate ◽  
Spectral Lines ◽  
Interstellar Gas ◽  
Interstellar Molecules ◽  
Star Forming ◽  
Star Forming Regions

The Herschel-guaranteed time key programme PRobing InterStellar Molecules with Absorption line Studies (PRISMAS) 1 is providing a survey of the interstellar hydrides containing the elements C, O, N, F and Cl. As the building blocks of interstellar molecules, hydrides provide key information on their formation pathways. They can also be used as tracers of important physical and chemical properties of the interstellar gas that are difficult to measure otherwise. This paper presents an analysis of two sight-lines investigated by the PRISMAS project, towards the star-forming regions W49N and W51. By combining the information extracted from the detected spectral lines, we present an analysis of the physical properties of the diffuse interstellar gas, including the electron abundance, the fraction of gas in molecular form, and constraints on the cosmic ray ionization rate and the gas density.

Charge Exchange Ionization (CEI)

2016 ◽  
Author(s):  
Kermit K. Murray ◽  
Robert K. Boyd ◽  
Marcos N. Eberlin ◽  
G. John Langley ◽  
Liang Li ◽  
...  
Keyword(s):  
Charge Exchange ◽  
Charge Exchange Ionization
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