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A solid density target irradiated by a high-intensity laser pulse can become relativistically transparent, which then allows it to sustain an extremely strong laser-driven longitudinal electron current. The current generates a filament with…

Plasma Physics · Physics 2019-01-30 Tao Wang , Toma Toncian , Mingsheng Wei , Alexey Arefiev

The universe in large scales is structured as a network known as cosmic web. Filaments are one of the structural components of this web, which can be introduced as a novel probe to study the formation and evolution of structures and as a…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-16 Mohammad Ansari Fard , Sina Taamoli , Shant Baghram

Strong Alfv\'enic turbulence develops eddy-like motions perpendicular to the local direction of magnetic fields. This local alignment induces velocity gradients perpendicular to the local direction of the magnetic field. We use this fact to…

Astrophysics of Galaxies · Physics 2017-01-25 Diego F. González-Casanova , A. Lazarian

Hand-drawn synoptic maps from the Meudon Observatory (1919 onwards) and the McIntosh archive (1967 onwards) are two important sources of long-term, manually recorded filament observations. In this study, we calibrate the Meudon maps and…

Solar and Stellar Astrophysics · Physics 2021-10-13 Rakesh Mazumder , Subhamoy Chatterjee , Dibyendu Nandy , Dipankar Banerjee

Thread-like structures are pervasive across scales, from polymeric proteins to root systems to galaxy filaments, and their characteristics can be readily investigated in the network formalism. Yet, network links usually represent only parts…

Data Structures and Algorithms · Computer Science 2017-06-01 David Breuer , Zoran Nikoloski

In this work, we identify and analyse the properties of cluster-cluster filaments within a cosmological simulation assuming that they are structures connecting maxima of the density field defined by dark matter halos with masses $M \, \ge…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-25 Luis A. Pereyra , Mario A. Sgró , Manuel E. Merchán , Federico A. Stasyszyn , Dante J. Paz

This paper proposes a novel kernel approach to linear dimension reduction for supervised learning. The purpose of the dimension reduction is to find directions in the input space to explain the output as effectively as possible. The…

Machine Learning · Statistics 2011-09-05 Kenji Fukumizu , Chenlei Leng

Current constraints on models of galaxy evolution rely on morphometric catalogs extracted from multi-band photometric surveys. However, these catalogs are altered by selection effects that are difficult to model, that correlate in non…

Instrumentation and Methods for Astrophysics · Physics 2017-09-06 Sébastien Carassou , Valérie de Lapparent , Emmanuel Bertin , Damien Le Borgne

Magnetic fields, while ubiquitous in many astrophysical environments, are challenging to measure observationally. Based on the properties of anisotropy of eddies in magnetized turbulence, the Velocity Gradient Technique is a method…

Fluorescent molecules emit light in a dipole radiation pattern that can be used to infer their orientation through defocused fluorescence microscopy. Proper measurement of the orientation requires mathematical modeling of the radiation…

Optics · Physics 2025-08-07 E. Dey , M. Elorza , F. W. Foss , J. J. Gomez Cadenas , B. J. P. Jones

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 fields is the issue that the grain alignment theory…

Astrophysics · Physics 2016-08-30 A. Lazarian , J. Cho

We have examined the global structure of the solar magnetic field using data from the FeI spectral line at {\lambda}5250.2{\AA} obtained at the 150-foot tower telescope at the Mt. Wilson Observatory (MWO). For each point on the solar…

Solar and Stellar Astrophysics · Physics 2015-06-15 Roger K. Ulrich , Tham Tran

We use numerical simulations of turbulent cluster-forming regions to study the nature of dense filamentary structures in star formation. Using four hydrodynamic and magnetohydrodynamic simulations chosen to match observations, we identify…

Astrophysics of Galaxies · Physics 2015-06-23 Helen Kirk , Ralph Pudritz , Mikhail Klassen , Samantha Pillsworth

We use extensive 350 um polarimetry and continuum maps obtained with Hertz and SHARC II along with HCN and HCO+ spectroscopic data to trace the orientation of the magnetic field in the Orion A star-forming region. Using the polarimetry…

A novel method for automated assessment of directions of collagen fibers in soft tissues is presented. It is based on multiple rotated images obtained via polarized light microscope with perpendicular and inclined polarizers and thus it…

We propose a new multiscale method to calculate the amplitude of the gradient of the linear polarisation vector using a wavelet-based formalism. We demonstrate this method using a field of the Canadian Galactic Plane Survey (CGPS) and show…

Astrophysics of Galaxies · Physics 2016-03-21 J. -F. Robitaille , A. M. M. Scaife

We report on two quantitative, morphological estimators of the filamentary structure of the Cosmic Web, the so-called global and local skeletons. The first, based on a global study of the matter density gradient flow, allows us to study the…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Christophe Pichon , Christophe Gay , Dmitry Pogosyan , Simon Prunet , Thierry Sousbie , Stephane Colombi , Adrianne Slyz , Julien Devriendt

We analyse the morphology and kinematics of dense filamentary structures produced in a numerical simulation of a star--forming cloud of $1.4 \times 10^4 \, \Msun$ evolving under their own self--gravity in a magnetized medium. This study is…

Astrophysics of Galaxies · Physics 2017-09-20 Manuel Zamora-Avilés , Javier Ballesteros-Paredes , Lee W. Hartmann

Polar fields at the minimum of a sunspot cycle -- which are a manifestation of the radial component of the Sun's poloidal field -- are deemed to be the best indicator of the strength of the toroidal component, and hence the amplitude of the…

Solar and Stellar Astrophysics · Physics 2025-10-15 Srinjana Routh , Shaonwita Pal , Dibyendu Nandy , Subhamoy Chatterjee , Dipankar Banerjee , Mohd. Saleem Khan

Context. Bright heads of penumbral filaments, penumbral grains (PGs), show apparent horizontal motions inwards, towards the umbra, or outwards, away from the umbra. Aims. We aim to prove statistically whether the direction of PGs' apparent…

Solar and Stellar Astrophysics · Physics 2023-11-29 Michal Sobotka , Jan Jurčák , J. Sebastián Castellanos Durán , Marta García-Rivas