Related papers: Low energy cosmic rays
Cosmic-ray energy densities in central regions of starburst galaxies, as inferred from radio and gamma-ray measurements of, respectively, non-thermal synchrotron and neutral pion decay emission, are typically U_p = O(100)eV/cm3, i.e.…
Solar flare observations are used to demonstrate the new technique of abundance determination based on gamma ray line emission produced by accelerated particle bombardment. Some of the implications of similar gamma ray line emission…
Cosmic rays are crucial for the chemistry of molecular clouds and their evolution. They provide essential ionizations, dissociations, heating and energy to the cold, dense cores. As cosmic rays pierce through the clouds they are attenuated…
Low-energy cosmic rays ($<1$ TeV) are a pivotal source of ionisation of the interstellar medium, where they play a central role in determining the gas chemical composition and drastically influence the formation of stars and planets. Over…
The physics of energetic particle propagation in magnetised environments plays a crucial role in both the processes of acceleration and transport of cosmic rays. Recent theoretical developments in the field of cosmic ray research have been…
As long as magnetic fields remain frozen into the gas, the magnetic braking prevents the formation of protostellar discs. This condition is subordinate to the ionisation fraction characterising the inmost parts of a collapsing cloud. The…
The study of the gamma-ray radiation produced by cosmic rays that escape their accelerators is of paramount importance for (at least) two reasons: first, the detection of those gamma-ray photons can serve to identify the sources of cosmic…
Low-frequency radio observations of diffuse synchrotron radiation offer a unique vantage point for investigating the intricate relationship between gas and magnetic fields in the formation of structures within the Galaxy, spanning from the…
The propagation of high-energy cosmic rays through giant molecular clouds constitutes a fundamental process in astronomy and astrophysics. The diffusion of cosmic-rays through these magnetically turbulent environments is often studied…
We demonstrate for the first time that Galactic cosmic rays with energies as high as 1e10 eV can trigger a cascade of low-energy (< 20 eV) secondary electrons that could be a significant contributor to the interstellar synthesis of…
Low energy galactic cosmic rays as well as particles accelerated to high energies either at the solar surface or in the interplanetary medium have access to the atmosphere above a given position on the Earth depending upon the state of the…
We consider the rate of ionization of diffuse and molecular clouds in the interstellar medium by Galactic cosmic rays (GCR) in order to constrain its low energy spectrum. We extrapolate the GCR spectrum obtained from PAMELA at high energies…
Cosmic rays (CRs) can significantly impact dense molecular clouds in galaxies, heating the interstellar medium (ISM) and altering its chemistry, ionization, and thermal properties. Their influence is particularly relevant in environments…
Low energy cosmic rays are the major ionization agents of molecular clouds. However, it has been shown that, if the cosmic ray spectrum measured by Voyager 1 is representative of the whole Galaxy, the predicted ionization rate in diffuse…
We assess the ionising effect of low energy protostellar cosmic rays in protoplanetary disks around a young solar mass star for a wide range of disk parameters. We assume a source of low energy cosmic rays located close to the young star…
Cosmic rays (CR) play an important role in dense molecular cores, affecting their thermal and dynamical evolution and initiating the chemistry. Several studies have shown that the formation of protostellar discs in collapsing clouds is…
When examining the abundance of elements in the placid interstellar medium, a deep hollow between helium and carbon becomes apparent. Notably, the fragile light nuclei Lithium, Beryllium, and Boron (collectively known as LiBeB) are not…
We will here discuss how the gamma-ray emission from molecular clouds can be used to probe the cosmic ray flux in distant regions of the Galaxy and to constrain the highly unknown cosmic ray diffusion coefficient. In particular we will…
In the absence of magnetic fields and cosmic rays, radiative cooling laws with a range of dependences on temperature affect the stability of interstellar gas. For about four and a half decades, astrophysicists have recognised the importance…
Cosmic rays produce molecular cluster ions as they pass through the lower atmosphere. Neutral molecular clusters such as dimers and complexes are expected to make a small contribution to the radiative balance, but atmospheric absorption by…