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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The Influence of Heavy Cosmic Rays in Energy Deposition in Molecular Clouds Employing the GEANT4 Code and Voyager I Data

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Author(s):
Pilling, Sergio [1] ; Pazianotto, Mauricio Tizziani [2] ; de Souza, Lucas Alves [2]
Total Authors: 3
Affiliation:
[1] Univ Vale Paraiba UNIVAP, Sao Jose Dos Campos - Brazil
[2] Inst Tecnol Aeronaut ITA, Sao Jose Dos Campos - Brazil
Total Affiliations: 2
Document type: Journal article
Source: ASTROPHYSICAL JOURNAL; v. 921, n. 2 NOV 2021.
Web of Science Citations: 0
Abstract

Galactic and extragalactic cosmic rays fully illuminate and trigger several physical and physicochemical changes in molecular clouds (MCs), including gas and grain heating, molecular destruction and formation, and molecular and atomic desorption (sputtering) from dust/ices to gas phase. Besides the major component in cosmic ray inventory (in flux) being electrons, protons, and alphas, particles with larger atomic numbers have a higher rate of energy delivery (due to richer cosmic ray showers) than the lighter particles, and this may add extra energy input into MCs. To understand this issue, we perform complementary calculations to the previous work on MCs, now adding the heavy ions (12 <= Z <= 29) in the cosmic ray incoming inventory. Once more, the calculations were performed employing the Monte Carlo toolkit GEANT4 code (considering nuclear and hadron physics). We observe that most projectiles in the heavy ion group have lower deposited energies (roughly 10 times less) than iron with the exception of magnesium (Z = 12) and silicon (Z = 14) which are about double. Cobalt presents the lowest deposited energies with respect to iron (only 0.5%). The total energy deposition in the current model was only roughly 10% higher (outer layers) and virtually the same at the center of the cloud when compared with the previous model (with only protons + alphas + electrons sources). The results show that energy deposition by heavy ions is small compared with the values from light particles, and also suggest a very low temperature enhancement due to heavy ions within the MC, being the protons the dominant agent in the energy delivery and also in the cloud's heating. (AU)

FAPESP's process: 19/13577-0 - Computational platform for simulation of cosmic radiation in the aeronautical environment
Grantee:Maurício Tizziani Pazianotto
Support Opportunities: Regular Research Grants