相关论文: Testing analytical methods to derive the cosmic-ra…
The cosmic-ray ionization rate ($\zeta_2$) is one of the key parameters in star formation, since it regulates the chemical and dynamical evolution of molecular clouds by ionizing molecules and determining the coupling between the magnetic…
Context. Cosmic rays (CRs) play an important role in the chemistry and dynamics of the interstellar medium. In dense environments, they represent the main ionising agent, driving the rich chemistry of molecular ions and determining the…
Context: Cosmic rays drive several key processes for the chemistry and dynamical evolution of star-forming regions. Their effect is quantified mainly by means of the cosmic-ray ionisation rate $\zeta_2$. Aims: We aim to obtain a sample of…
Cosmic rays are a global source of ionisation, and the ionisation fraction represents a fundamental parameter in the interstellar medium. Ions couple to magnetic fields, affect the chemistry, and the dynamics of star-forming regions as well…
Cosmic rays (CRs) at sub-TeV energies play a fundamental role in the chemical and dynamical evolution of molecular clouds, as they control the ionisation, dissociation, and excitation of H$_{2}$. Their characterisation is important both for…
Stars and planets form within cold, dark molecular clouds. In these dense regions, where starlight cannot penetrate, cosmic rays (CRs) are the dominant source of ionization -- driving interstellar chemistry(Dalgarno (2006, PNAS, 103,…
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…
Chemistry in diffuse molecular clouds relies primarily on rapid ion-molecule reactions. Formation of the initial ions, H$^+$ and H$_2^+$, is dominated by cosmic-ray ionization of H and H$_2$, making the cosmic-ray ionization rate (denoted…
The energy spectrum of electrons produced in molecular gas by interstellar cosmic rays (CRs) is rigorously calculated as a function of gas column density $N$ traversed by the CRs. This allows us to accurately compute the local value of the…
We present a new method for the simultaneous calculation of the cosmic ray ionization rate, zeta(H2), and the ionization fraction, chi(e), in dense molecular clouds. A simple network of chemical reactions dominant in the creation and…
The cosmic-ray ionization rate (CRIR, $\zeta_2$) is one of the key parameters controlling the formation and destruction of various molecules in molecular clouds. However, the current most commonly used CRIR tracers, such as H$_3^+$, OH$^+$,…
A proper modelling of the cosmic-ray ionisation rate within gas clouds is crucial to describe their chemical evolution accurately. However, this modelling is computationally demanding because it requires the propagation of cosmic rays…
The spatial distribution of the cosmic-ray flux is important in understanding the Interstellar Medium (ISM) of the Galaxy. This distribution can be analyzed by studying different molecular species along different sight lines whose…
The ionization fraction is an important factor in determining the chemical and physical evolution of star forming regions. In the dense, dark starless cores of such objects, the ionization rate is dominated by cosmic rays; it is therefore…
Cosmic rays regulate the dynamics and the chemical processes in the densest and coldest regions of the ISM. Still, the determination of the cosmic-ray ionisation rate of H$_2$ (${\zeta^{\rm ion}_{{\rm H}_2}}$) is plagued by uncertainties in…
Low-energy cosmic rays are a fundamental source of ionization for molecular clouds, influencing their chemical, thermal and dynamical evolution. The purpose of this work is to explore the possibility that a low-energy component of…
All current estimates of the cosmic-ray (CR) ionization rate rely on assessments of the gas density along the probed sight lines. Until now, these have been based on observations of different tracers, with C$_2$ being the most widely used…
We utilize a modified astrochemistry code which includes cosmic ray attenuation in-situ to quantify the impact of different cosmic-ray models on the CO-to-H$_2$ and CI-to-H$_2$ conversion factors, $X_{\rm CO}$ and $X_{\rm CI}$,…
Cosmic rays are an important source of heating in the interstellar medium, in particular in dense molecular cloud cores shielded from the external ultraviolet radiation field. The limits placed on the cosmic-ray ionization rate from…
Low energy cosmic-rays (CRs) are responsible for gas heating and ionization of interstellar clouds, which in turn introduces coupling to Galactic magnetic fields. So far the CR ionization rate (CRIR) has been estimated using indirect…