English
Related papers

Related papers: Grain Alignment by Radiation in Dark Clouds and Co…

200 papers

Dust grains grow in interstellar clouds by accretion and coagulation. In this paper, we focus on these two grain growth processes and numerically investigate how they interplay to increase the grain radii. We show that accretion efficiently…

Astrophysics of Galaxies · Physics 2015-06-04 Hiroyuki Hirashita

Interstellar medium is turbulent and this induces relative motions of dust grains. We calculate relative velocities of charged grains in a partially ionized magnetized gas. We account for anisotropy of magnetohydrodynamic (MHD) turbulence,…

Astrophysics · Physics 2009-11-07 A. Lazarian , Huirong Yan

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…

Astrophysics of Galaxies · Physics 2020-09-09 Juris Kalvāns , Juris Roberts Kalnin

Magnetic fields are ubiquitous in the universe and are thought to play an important role in various astrophysical processes. Polarization of thermal dust emission from dust grains aligned with the magnetic field is widely used to measure…

Astrophysics of Galaxies · Physics 2024-02-20 Thiem Hoang , Bao Truong

Recent observation of 850 micron sub-mm polarization from T Tauri disks opens up the possibility of studying magnetic field structure within protostellar disks. The degree of polarization is around 3 % and the direction of polarization is…

Solar and Stellar Astrophysics · Physics 2009-01-21 Jungyeon Cho , A. Lazarian

We present theoretical calculations of the X-ray scattering properties of porous grain aggregates with olivine monomers. The small and large angle scattering properties of these aggregates are governed by the global structure and…

Astrophysics of Galaxies · Physics 2009-06-05 Kevin Heng , Bruce T. Draine

Investigating the dust grain size and its dependence on substructures in protoplanetary disks is a crucial step in understanding the initial process of planet formation. Spectral indices derived from millimeter observations are used as a…

Earth and Planetary Astrophysics · Physics 2024-10-08 Dafa Li , Yao Liu , Hongchi Wang , Min Fang , Lei Wang

Context. Anomalous microwave emission (AME) is a component of interstellar medium emission peaking at 10-60 GHz. Its polarization is both a CMB foreground and a probe of the alignment physics of very small dust grains. Aims. We quantify…

Astrophysics of Galaxies · Physics 2026-04-30 Boy Lankhaar

We discuss the radiative transfer theory for translucent clouds illuminated by an extended background source. First we derive a rigorous solution based on the assumption that multiple scattering produce an isotropic flux. Then we derive a…

Solar and Stellar Astrophysics · Physics 2017-05-10 Davide Biganzoli , Marco Potenza , Massimo Robberto

Aims: Grain growth has been suggested as one possible explanation for the diminished dust optical depths in the inner regions of protoplanetary "transition" disks. In this work, we directly test this hypothesis in the context of current…

Solar and Stellar Astrophysics · Physics 2012-06-28 T. Birnstiel , S. M. Andrews , B. Ercolano

The HD 163296 disk shows ring and gap substructures with ALMA observations. In addition, this is the only disk where the rings and gaps are spatially resolved in millimeter-wave polarization measurements. In this paper, we conduct radiative…

Earth and Planetary Astrophysics · Physics 2020-01-08 Satoshi Ohashi , Akimasa Kataoka

We present a new gas-grain chemical model to constrain the effect of grain size distribution on molecular abundances in starless and pre-stellar cores. We introduce grain-size dependence simultaneously for cosmic-ray (CR)-induced desorption…

Astrophysics of Galaxies · Physics 2020-08-19 O. Sipilä , B. Zhao , P. Caselli

The dust sublimation walls of disks around T Tauri stars represent a directly observable cross-section through the disk atmosphere and midplane. Their emission properties can probe the grain size distribution and composition of the…

Earth and Planetary Astrophysics · Physics 2015-06-16 M. K. McClure , P. D'Alessio , N. Calvet , C. Espaillat , L. Hartmann , B. Sargent , D. M. Watson , L. Ingleby , J. Hernandez

Mixing grains with different properties is a remarkably challenging process, relevant to many industrial applications. Rotating drums have been used extensively as model systems to study granular media flow and mixing and segregation.…

Soft Condensed Matter · Physics 2018-09-05 Claudia Piacenza , Marco Marconati , Colin Hare , Andrea C. Santomaso , Marco Ramaioli

Dusty disks around young stars are formed out of interstellar dust that consists of amorphous, submicrometre grains. Yet the grains found in comets and meteorites, and traced in the spectra of young stars, include large crystalline grains…

Earth and Planetary Astrophysics · Physics 2010-11-02 Dejan Vinkovic

We study the physical processes that affect the alignment of grains subject to radiative torques (RATs). To describe the action of RATs, we use the analytical model (AMO) of RATs introduced in Paper I. We focus our discussion on the…

Astrophysics · Physics 2009-06-23 Thiem Hoang , Alex Lazarian

Interstellar dust grains can be spun up by radiative torques, and the resulting centrifugal force may be strong enough to disrupt large dust grains. We examine the effect of this rotational disruption on the evolution of grain size…

Astrophysics of Galaxies · Physics 2020-04-08 Hiroyuki Hirashita , Thiem Hoang

The origin of the grains with diameters less than 4 micron from the inclusions in Antarctic ice cores is discussed. It is proposed that these grains were initiated by ions stopped in the upper atmosphere. The ions form molecules, which…

Geophysics · Physics 2009-09-29 W. Baltensperger , W. Woelfli

Observations of far-infrared (FIR) and submillimeter (SMM) polarized emission are used to study magnetic fields and dust grains in dense regions of the interstellar medium (ISM). These observations place constraints on models of molecular…

Astrophysics · Physics 2009-03-19 John E. Vaillancourt

We present a new method for using the observed starlight polarization and polarized submm emission to constrain the shapes and porosities of interstellar grains. We present the modified picket fence approximation (MPFA), and verify that it…

Astrophysics of Galaxies · Physics 2021-10-04 B. T. Draine , Brandon S. Hensley