Estimation of Magnetic Field Strength in the Turbulent Warm Ionized Medium (2009)
Wu, Qingwen, Kim, Jongsoo, Ryu, Dongsu, Cho, Jungyeon, Alexander, Paul
We studied Faraday rotation measure (RM) in turbulent media with the rms Mach number of unity, using isothermal, magnetohydrodynamic turbulence simulations. Four cases with different values of...
Stringent Limits on the Polarized Submillimeter Emission from Protoplanetary Disks (2009)
Hughes, A. Meredith, Wilner, David J., Cho, Jungyeon, Marrone, Daniel P., Lazarian, Alexandre, Andrews, Sean M., ...
We present arcsecond-resolution Submillimeter Array (SMA) polarimetric observations of the 880 um continuum emission from the protoplanetary disks around two nearby stars, HD 163296 and TW Hydrae....
Characteristic Lengths of Magnetic Field in Magnetohydrodynamic Turbulence (2009)
In the framework of turbulence dynamo, flow motions amplify a weak seed magnetic field through the stretching of field lines. Although the amplification process has been a topic of active research,...
Simulations of Electron Magnetohydrodynamic Turbulence (2009)
We present numerical simulations of electron magnetohydrodynamic (EMHD) and electron reduced MHD (ERMHD) turbulence. Comparing scaling relations, we find that both EMHD and ERMHD turbulence show...
Polarization of FIR emission from T Tauri Disks (2008)
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...
We present statistical analysis of diffuse Galactic synchrotron emission and polarized thermal emission from dust. Both Galactic synchrotron emission and polarized thermal emission from dust reflect...
Internal Extinction in the SDSS Late-Type Galaxies (2008)
We study internal extinction of late-type galaxies in the Sloan Digital Sky Survey. We find that the degree of internal extinction depends on both the concentration index c and K_s-band absolute...
Turbulence and Magnetic Fields in the Large Scale Structure of the Universe (2008)
Ryu, Dongsu, Kang, Hyesung, Cho, Jungyeon, Das, Santabrata
The nature and origin of turbulence and magnetic fields in the intergalactic space are important problems that are yet to be understood. We propose a scenario in which turbulent flow motions are...
Propagation of UHE Protons through Magnetized Cosmic Web (2008)
Das, Santabrata, Kang, Hyesung, Ryu, Dongsu, Cho, Jungyeon
If ultra-high-energy cosmic rays (UHECRs) originate from extragalactic sources, understanding the propagation of charged particles through the magnetized large scale structure (LSS) of the universe...
Propagation of UHE protons through a magnetized large scale structure (2007)
Kang, Hyesung, Das, Santabrata, Ryu, Dongsu, Cho, Jungyeon
The propagation of UHECRs is affected by the intergalactic magnetic fields that were produced during the course of the large scale structure formation of the universe. We adopt a novel model where...
A Comparative Study of Velocity Statistics of Hydrodynamic and Magnetohydrodynamic Turbulence (2006)
Hall, Nicholas, Kowal, G., Lazarian, A., Cho, Jungyeon
Turbulence in an incompressible fluid with and without a magnetic field as well as moderately compressible MHD turbulence are compared. For the magnetohydrodynamic (MHD) models the probability...
Grain Alignment and Polarized Emission from Magnetized T Tauri Disks (2006)
The structure of magnetic fields within protostellar disks may be studied via polarimetry provided that grains are aligned in respect to magnetic field within the disks. We explore alignment of dust...
Particle Acceleration by MHD Turbulence (2005)
Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of particle acceleration. We make use of the recently established scaling of slow and fast...
Magnetic turbulence in compressible fluids (2004)
We present high resolution numerical simulations of compressible magnetohydrodynamic (MHD) turbulence. We concentrate on studies of spectra and anisotropy of velocity and density. We describe a...
Simulation of Relativistic Force-free Magnetohydrodynamic Turbulence (2004)
We present numerical studies of 3-dimensional magnetohydrodynamic (MHD) turbulence in a strongly magnetized medium in the extremely relativistic limit, in which the inertia of the charge carriers can...
The Anisotropy of Electron MHD Turbulence (2004)
We present numerical studies of 3-dimensional electron magnetohydrodynamic (EMHD) turbulence. We investigate cascade timescale and anisotropy of freely decaying strong EMHD turbulence with zero...
Ordinary and Viscosity-Damped MHD Turbulence (2003)
Cho, Jungyeon, Lazarian, A., Vishniac, Ethan T.
We compare the properties of ordinary strong magnetohydrodynamic (MHD) turbulence in a strongly magnetized medium with the recently discovered viscosity-damped regime. We focus on energy spectra,...
The Radio-FIR correlation: Is MHD Turbulence the Cause? (2003)
Groves, Brent, Cho, Jungyeon, Dopita, Michael, Lazarian, Alex
The radio - far infrared correlation is one of the tightest correlations found in astronomy. Many of the models explaining this correlation rely on the association of of global magnetic field...
Generation of Compressible Modes in MHD Turbulence (2003)
Astrophysical turbulence is magnetohydrodynamic (MHD) in its nature. We discuss fundamental properties of MHD turbulence. In particular, we discuss the generation of compressible MHD waves by...
We present numerical simulations and explore scalings and anisotropy of compressible magnetohydrodynamic (MHD) turbulence. Our study covers both gas pressure dominated (high beta) and magnetically...
Compressible MHD Turbulence: Mode Coupling, Anisotropies and Scalings (2002)
Compressible turbulence, especially the magnetized version of it, traditionally has a bad reputation with researchers. However, recent progress in theoretical understanding of incompressible MHD as...
The Properties of Compressible MHD and Cosmic Ray Transport (2002)
Lazarian, A., Cho, Jungyeon, Yan, Huirong
Turbulence is the most common state of astrophysical flows. In typical astrophysical fluids, turbulence is accompanied by strong magnetic fields, which has a large impact on the dynamics of the...
Polarized Foreground Emission from Dust: Grain Alignment and MHD Turbulence (2002)
Aligned grains present a foreground for cosmic microwave emission studies. We review basic physical processes involved in grain alignment and discuss the niches for different alignment mechanisms. We...
Esquivel, Alejandro, Lazarian, A., Pogosyan, D., Cho, Jungyeon
In a previous work Lazarian and Pogosyan suggested a technique to extract velocity and density statistics, of interstellar turbulence, by means of analysing statistics of spectral line data cubes. In...
Compressible Sub-Alfvenic MHD turbulence in Low-beta Plasmas (2002)
We present a model for compressible sub-Alfvenic isothermal magnetohydrodynamic (MHD) turbulence in low-beta plasmas and numerically test it. We separate MHD fluctuations into 3 distinct families -...
MHD Turbulence as a Foreground for CMB Studies (2002)
Measurements of intensity and polarization of diffuse Galactic synchrotron emission as well as starlight polarization reveal power law spectra of fluctuations. We show that these fluctuations can...
MHD Turbulence: Scaling Laws and Astrophysical Implications (2002)
Cho, Jungyeon, Lazarian, A., Vishniac, Ethan
Turbulence is the most common state of astrophysical flows. In typical astrophysical fluids, turbulence is accompanied by strong magnetic fields, which has a large impact on the dynamics of the...
Scaling of ISM Turbulence: Implications for HI (2001)
Cho, Jungyeon, Lazarian, Alex, Yan, Huirong
Galactic HI is a gas that is coupled to magnetic field because of its fractional ionization. Many properties of HI are affected by turbulence. Recently, there has been a significant breakthrough on...
New Regime of MHD Turbulence: Cascade Below Viscous Cutoff (2001)
Cho, Jungyeon, Lazarian, A., Vishniac, Ethan
In astrophysical situations, e.g. in the interstellar medium (ISM), neutrals can provide viscous damping on scales much larger than the magnetic diffusion scale. Through numerical simulations, we...
Numerical Simulations of Incompressible MHD Turbulence (2001)
The study of incompressible magnetohydrodynamic (MHD) turbulence gives useful insights on many astrophysical problems. We describe a pseudo-spectral MHD code suitable for the study of incompressible...
Simulations of MHD Turbulence in a Strongly Magnetized Medium (2001)
Cho, Jungyeon, Lazarian, Alex, Vishniac, Ethan
We analyze 3D numerical simulations of driven incompressible magnetohydrodynamic (MHD) turbulence in a periodic box threaded by a moderately strong external magnetic field. We sum over nonlinear...
Magnetic Helicity Conservation and Astrophysical Dynamos (2000)
Vishniac, Ethan T., Cho, Jungyeon
We construct a magnetic helicity conserving dynamo theory which incorporates a calculated magnetic helicity current. In this model the fluid helicity plays a small role in large scale magnetic field...
The Anisotropy of MHD Alfv\'{e}nic Turbulence (2000)
Cho, Jungyeon, Vishniac, Ethan T.
We perform direct 3-dimensional numerical simulations for magnetohydrodynamic (MHD) turbulence in a periodic box of size $2\pi$ threaded by strong uniform magnetic fields. We use a pseudo-spectral...
The Generation of Magnetic Fields Through Driven Turbulence (2000)
Cho, Jungyeon, Vishniac, Ethan T.
We have tested the ability of driven turbulence to generate magnetic field structure from a weak uniform field using three dimensional numerical simulations of incompressible turbulence. We used a...