相关论文: Cosmic rays and grain alignment

Cosmic-ray-induced whole-grain heating induces evaporation and other processes that affect the chemistry of interstellar clouds. With recent data on grain heating frequencies as an input for a modified rate-equation astrochemical model,…

Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of cosmic rays inside a cloud also determines the $\gamma$-ray flux produced by…

Cosmic-rays are the primary initiators of interstellar chemistry, and getting a better understanding of the varying impact they have on the chemistry of interstellar clouds throughout the Milky Way will not only expand our understanding of…

Synchrotron radiation from cosmic rays is a key observational probe of the galactic magnetic field. Interpreting synchrotron emission data requires knowledge of the cosmic ray number density, which is often assumed to be in energy…

During the evolution of protoplanetary disks, dust grains start to grow, form larger particles, settle to the midplane, and rearrange the disk, mainly by the inward radial drift. Because of this, dust pebbles with an irregular shape usually…

The density of cosmic rays inside molecular clouds determines the ionization rate in the dense cores where stars form. It is also one of the drivers of astrochemistry leading to the creation of complex molecules. Through Fermi Large Area…

We discuss the dynamics of dust grains subjected to uncompensated torques arising from H_2 formation. In particular, we discuss grain dynamics when a grain spins down and goes through a ``crossover''. As first pointed out by Spitzer &…

Several sets of data show that small interstellar grains captured in interstellar magnetic fields draped over the heliosphere appear to polarize the light of nearby stars. The maximum polarization direction is offset in ecliptic longitude…

Recent results from multi-wavelength observations of the inner few hundred pc of the Galactic center have added two new characteristics to the ISM in this unique region. One is the cosmic ray ionization rate derived from H$_3^+$…

We study the properties of cosmic-ray (CR) driven galactic winds from the warm interstellar medium using idealized spherically symmetric time-dependent simulations. The key ingredients in the model are radiative cooling and…

Paramagnetic alignment of non-spherical dust grains rotating at thermal velocities is studied. The analytical solution is found for the alignment measure of oblate grains. Perturbative approach is used for solving the problem. It is shown…

Grain-surface reactions play an essential role in interstellar chemistry, since dust grain catalyses reactions at its surface allowing for the formation of molecules. We used a chemical model in which both gas-phase and grain-surface…

Context. While radiative cooling of interstellar grains is a well-known process, little detail is known about the cooling of grains with an icy mantle that contains volatile adsorbed molecules. Aims. We explore basic details for the cooling…

There is a long-standing discussion in the astrophysical/astrochemical community as to the structure and morphology of dust grains in various astrophysical environments (e.g., interstellar clouds, protostellar envelopes, protoplanetary and…

Radiative Torques (RATs) or Mechanical Torques (METs) acting on irregular grains can induce the alignment of dust grains in respect to the alignment axis (AA), which can be either the direction of the magnetic field, or the direction of the…

Context. Evaporative (sublimation) cooling of icy interstellar grains occurs when the grains have been suddenly heated by a cosmic-ray (CR) particle or other process. It results in thermal desorption of icy species, affecting the chemical…

Interstellar grain alignment studies are currently experiencing a renaissance due to the development of a new quantitative theory based on Radiative Alignment Torques (RAT). One of the distinguishing predictions of this theory is a…

Cosmic-ray-induced sputtering is one of the important desorption mechanisms at work in astrophysical environments. The chemical evolution observed in high-density regions, from dense clouds to protoplanetary disks, and the release of…

The Zeeman effect and dust grain alignment are two major methods for probing magnetic fields (B-fields) in molecular clouds, largely motivated by the study of star formation, as the B-field may regulate gravitational contraction and channel…

In this analysis we illustrate how the relatively new emission mechanism known as spinning dust can be used to characterize dust grains in the interstellar medium. We demonstrate this by using spinning dust emission observations to…