Prof. Eric Herbst
The gas-phase chemistry of interstellar clouds is powered by ionization caused by primary cosmic rays, mainly protons, and secondary electrons. The cosmic ray ionization rate throughout a cloud, ζH, can be estimated based on the initial energy spectrum entering a cloud. However, there are a number of uncertainties, including poor knowledge of the flux of the lowest energy cosmic rays,...
Dr Cecilia Ceccarelli
Dr Paul Rimmer (Ohio State university Colombus)
MOTIVATION: Low energy ($< 1$ GeV) cosmic rays drive interstellar chemistry and may cause specific spectral features recently measured, such as the 6.7 keV emission line. Yet the origin and flux of low energy cosmic rays is currently unknown because the Sun's magnetic field deflects these particles, so that they cannot be directly observed. A robust model of cosmic ray transport in molecular...
Dr Alexandre Faure (IPAG Grenoble)
In the most energetic regions of space (shocks, photodissociation regions, comets, etc.), the electron fraction, xe, can increase by several orders of magnitude. When xe exceeds about 10-5, free electrons can compete or even dominate over neutrals in the collisional excitation of molecules. Recent theoretical studies, based on the UK molecular R-matrix method, have revisited the...
Dr Franck Lepetit (LUTH Meudon)
Cosmic rays have a strong impact on interstellar chemistry. By ionizing some species, they initiate fast ion-neutral reactions that lead to the formation of complex molecules. So, the measurement of the cosmic ionization rate in different media is crucial to understand the chemical mechanism leading to the composition of interstellar clouds. In diffuse interstellar gas, the abundances of...
Dr Ilya Usoskin
An important factor affecting the terrestrial environment is the flux of cosmic rays permanently impinging on Earth. Energetic cosmic rays initiate a nucleonic-electromagnetic cascade in the atmosphere, affecting its physical-chemical properties. In particular, cosmic rays form the dominant source of ionization in the lower and middle atmosphere. Therefore, a detailed knowledge of processes...
42. Phase lags between 11-yr cycles of Sunspot Number, Cosmic Ray Flux and Length of Day time series.
Dr Edouard Bard (CEREGE Aix-en-Provence)
We analyzed phase lags between the 11-year cycles of solar activity (sunspot numbers, SSN), cosmic ray flux (CRF) and 0.5-year oscillations of the length of day (LOD). The analysis is performed for the solar cycles number 20-23 (1965-2010). Phase lags are calculated by using different methods: time lag between maxima of corresponding cycles, according to maximal coefficient of...