Publications (37)
Using SPICA Space Telescope to characterize Exoplanets
J. R. Goicoechea, B. Swinyard, G. Tinetti +26
We present the 3.5m SPICA space telescope, a proposed Japanese-led JAXA-ESA mission scheduled for launch around 2017. The actively cooled (<5 K), single aperture telescope and mono…
Density scaling and anisotropy in supersonic MHD turbulence
A. Beresnyak, A. Lazarian, J. Cho
We study the statistics of density for supersonic turbulence in a medium with magnetic pressure larger than the gaseous pressure. This study is motivated by molecular cloud researc…
Dust polarized emission observations of NGC 6334; BISTRO reveals the details of the complex but organized magnetic field structure of the high-mass star-forming hub-filament network
D. Arzoumanian, R. Furuya, T. Hasegawa +145
[Abridged] Filaments and hubs have received special attention recently thanks to studies showing their role in star formation. While the column density and velocity structures of b…
Physics of Gamma-Ray Bursts: Turbulence, Energy Transfer and Reconnection
A. Lazarian, V. Petrosian, H. Yan +1
Understanding of the nature of gamma-ray bursts (GRBs) is one of the challenging problem facing the astrophysics community. The field of gamma ray bursts is a rapidly developing on…
Skyrmion confinement and dynamics in tracks patterned with magnetic anisotropy: theory and simulations
E. Tamura, C. Liu, S. Miki +5
Skyrmion is a topologically protected spin texture excited in magnetic thin films. The radii of skyrmions are typically 10-100 nm. Because of the size, the skyrmion is expected to…
MHD Turbulence Simulation in a Cosmic Structure Context
T. W. Jones, D. H. Porter, D. Ryu +1
The gaseous media of galaxy clusters and cosmic filaments, which constitute most of the baryonic matter in the universe, is highly dynamic. It is also probably turbulent, although…
Diversity among other worlds: characterization of exoplanets by direct detection
J. Schneider, A. Boccaletti, A. Aylward +34
The physical characterization of exoplanets will require to take spectra at several orbital positions. For that purpose, a direct imaging capability is necessary. Direct imaging re…
The phase-dependent Infrared brightness of the extrasolar planet upsilon Andromedae b
J. Harrington, B. Hansen, S. Luszcz +5
The star upsilon Andromeda is orbited by three known planets, the innermost of which has an orbital period of 4.617 days and a mass at least 0.69 that of Jupiter. This planet is cl…
Response of wavelength-shifting and scintillating-wavelength-shifting fibers to ionizing radiation
W. Bae, J. Cesar, K. Chen +23
We report results of characterizing the response and light transport of wavelength-shifting (WLS) and scintillating-wavelength-shifting (Sci-WLS) fibers under irradiation by radioa…
The Catalogue for Astrophysical Turbulence Simulations (CATS)
B. Burkhart, S. Appel, S. Bialy +18
Turbulence is a key process in many fields of astrophysics. Advances in numerical simulations of fluids over the last several decades have revolutionized our understanding of turbu…
Deep Neural Network (DNN) for Water/Fat Separation: Supervised Training, Unsupervised Training, and No Training
R. Jafari, P. Spincemaille, J. Zhang +6
Purpose: To use a deep neural network (DNN) for solving the optimization problem of water/fat separation and to compare supervised and unsupervised training. Methods: The current T…
Magnetic Field Structure and Stochastic Reconnection in a Partially Ionized Gas
A. Lazarian, E. T. Vishniac, J. Cho
We consider stochastic reconnection in a magnetized, partially ionized medium. Stochastic reconnection is a generic effect, due to field line wandering, in which the speed of recon…
Effects of the magnetic field direction on the Tsallis statistic
Diego F. González-Casanova, A. Lazarian, J. Cho
We extend the use of the Tsallis statistic to measure the differences in gas dynamics relative to the mean magnetic field present from natural eddy-type motions existing in magneto…
Scaling, Intermittency and Decay of MHD Turbulence
A. Lazarian, J. Cho
We discuss a few recent developments that are important for understanding of MHD turbulence. First, MHD turbulence is not so messy as it is usually believed. In fact, the notion of…
Problems and Progress in Astrophysical Dynamos
E. T. Vishniac, A. Lazarian, J. Cho
Astrophysical objects with negligible resistivity are often threaded by large scale magnetic fields. The generation of these fields is somewhat mysterious, since a magnetic field i…
MHD Turbulent Mixing Layers: Equilibrium Cooling Models
A. Esquivel, R. A. Benjamin, A. Lazarian +2
We present models of turbulent mixing at the boundaries between hot (T~10^{6-7} K) and warm material (T~10^4 K) in the interstellar medium, using a three-dimensional magnetohydrody…
Effects of Radiative Transfer on the Observed Anisotropy in MHD Turbulent Molecular Simulations
D. Hernández-Padilla, A. Esquivel, A. Lazarian +2
We study the anisotropy of centroid and integrated intensity maps with synthetic observations. We perform post-process radiative transfer including the optically thick regime that…
Alfvenic Turbulence Beyond the Ambipolar Diffusion Scale
Blakesley Burkhart, A. Lazarian, D. Balsara +2
We investigate the nature of the Alfvénic turbulence cascade in two fluid MHD simulations in order to determine if turbulence is damped once the ion and neutral species become dec…
Sensor operating point calibration and monitoring of the ALICE Inner Tracking System during LHC Run 3
D. Agguiaro, G. Aglieri Rinella, L. Aglietta +282
The new Inner Tracking System (ITS2) of the ALICE experiment began operation in 2021 with the start of LHC Run 3. Compared to its predecessor, ITS2 offers substantial improvements…
Velocity Centroids Anisotropy and the Signature of different MHD Modes in the Turbulent ISM
D. Hernández-Padilla, A. Esquivel, A. Lazarian +3
Magnetic turbulence is anisotropic as the directions of motion are constrained by the magnetic field. Such anisotropy can be observed in velocity centroids obtained from spectrosco…
At-Speed Logic BIST for IP Cores
B. Cheon, E. Lee, L. -T. Wang +6
This paper describes a flexible logic BIST scheme that features high fault coverage achieved by fault-simulation guided test point insertion, real at-speed test capability for mult…
Magnetic Reconnection and Turbulent Mixing: From ISM to Clusters of Galaxies
A. Lazarian, J. Cho
Magnetic reconnection, or the ability of the magnetic field lines that are frozen in plasma to change their topology, is a fundamental problem of magnetohydrodynamics (MHD). We bri…
Discrete -nets and Guichard nets via discrete Koenigs nets
F. E. Burstall, J. Cho, U. Hertrich-Jeromin +2
We provide a convincing discretisation of Demoulin's -surfaces along with their specialisations to Guichard and isothermic surfaces with no loss of integrable structure.
Optical characterization of wavelength-shifting and scintillating-wavelength-shifting fibers
W. Bae, J. Cesar, K. Chen +23
We report results of optical characterizations of new wavelength-shifting and scintillating-wavelength-shifting fibers EJ-182 and EJ-160 from Eljen Technology and compare them to t…
FOSSIL: Regret-minimizing weighting for robust learning under imbalance and small data
J. Cha, J. Lee, J. Cho +1
Imbalanced and small data regimes are pervasive in domains such as rare disease imaging, genomics, and disaster response, where labeled samples are scarce and naive augmentation of…
Theory and Applications of Non-Relativistic and Relativistic Turbulent Reconnection
A. Lazarian, G. Kowal, M. Takamoto +2
Realistic astrophysical environments are turbulent due to the extremely high Reynolds numbers. Therefore, the theories of reconnection intended for describing astrophysical reconne…
The Effects of Clumps in Explaining X-ray Emission Lines from Hot Stars
J. P. Cassinelli, R. Ignace, W. L. Waldron +3
It is now well established that stellar winds of hot stars are fragmentary and that the X-ray emission from stellar winds has a strong contribution from shocks in winds. Chandra hi…
Thermal Conduction in Magnetized Turbulent Gas
J. Cho, A. Lazarian, A. Honein +3
Using numerical methods, we systematically study in the framework of ideal MHD the effect of magnetic fields on heat transfer within a turbulent gas. We measure the rates of passiv…
CHIMPS2: Survey description and CO emission in the Galactic Centre
D. J. Eden, T. J. T. Moore, M. J. Currie +103
The latest generation of Galactic-plane surveys is enhancing our ability to study the effects of galactic environment upon the process of star formation. We present the first data…
Alignment of Dust in Molecular Clouds
A. Lazarian, J. Cho
Polarimetry is one of the most informative techniques of studying magnetic fields in molecular clouds. How reliable the interpretation of the polarization maps in terms of magnetic…
Emergence of stationary many-body entanglement in driven-dissipative Rydberg lattice gases
S. K. Lee, J. Cho, K. S. Choi
Non-equilibrium quantum dynamics represents an emerging paradigm for condensed matter physics, quantum information science, and statistical mechanics. Strongly interacting Rydberg…
Basic Properties of Compressible MHD Turbulence: Implications for Molecular Clouds
A. Lazarian, J. Cho
Recent advances in understanding of the basic properties of compressible Magnetohydrodynamic (MHD) turbulence call for revisions of some of the generally accepted concepts. First,…
Growth of Magnetic Fields Induced by Turbulent Motions
J. Cho, E. Vishniac, A. Beresnyak +2
We present numerical simulations of driven magnetohydrodynamic (MHD) turbulence with weak/moderate imposed magnetic fields. The main goal is to clarify dynamics of magnetic field g…
Grain Alignment by Radiation in Dark Clouds and Cores
J. Cho, A. Lazarian
We study alignment of grains by radiative torques. We found steep rise of radiative torque efficiency as grain size increases. This allows larger grains that are known to exist wit…
Diffusion of magnetic field and removal of magnetic flux from clouds via turbulent reconnection
R. Santos-Lima, A. Lazarian, E. M. de Gouveia Dal Pino +1
The diffusion of astrophysical magnetic fields in conducting fluids in the presence of turbulence depends on whether magnetic fields can change their topology via reconnection in h…
Polarimetry of DG Tau at 350 microns
M. Krejny, T. Matthews, G. Novak +4
We present the first 350 micron polarization measurement for the disk of the T Tauri star (TTS) DG Tau. The data were obtained using the SHARP polarimeter at the Caltech Submillime…
Globular Cluster Systems of Early-type Galaxies in Low-density Environments
J. Cho, R. M. Sharples, J. P. Blakeslee +4
Deep images of 10 early-type galaxies in low-density environments have been obtained with the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. The global properties…