The magnetic field structure of the Small Magellanic Cloud

In this paper, we analyze the stability of a homogeneous self-gravitating plasma, having a non-zero resistivity. This study provides a generalization of the Jeans paradigm for determining the critical scale above which gravitational collapse is allowed.We start by discussing the stability of an ideal self-gravitating plasma embedded in a constant magnetic field. We outline the existence of an anisotropic feature of the gravitational collapse. In fact, while in the plane orthogonal to the magnetic field the Jeans length is enhanced by the contribution of the magnetic pressure, outside this plane perturbations are governed by the usual Jeans criterium. The anisotropic collapse of a density contrast is sketched in details, suggesting that the linear evolution provides anisotropic initial conditions for the non-linear stage, where this effect could be strongly enforced.The same problem is then faced in the presence of non-zero resistivity and the conditions for the gravitational collapse are correspondingly extended. The relevant feature emerging in this resistive scenario is the cancellation of the collapse anisotropy in weakly conducting plasmas. In this case, the instability of a self-gravitating resistive plasma is characterized by the standard isotropic Jeans length in any directions. The limit of very small resistivity coefficient is finally addressed, elucidating how reminiscence of the collapse anisotropy can be found in the different value of the perturbation frequency inside and outside the plane orthogonal to the magnetic field.

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“…[3,4,5,6,7,8,9,10] and, more recently, Refs. [11,12,13,14,15,16,17,18]; see also Refs. [19,20,21,22,23] for review works).…”

Section: Introductionmentioning

confidence: 99%

Stability of a self-gravitating homogeneous resistive plasma

Pugliese

Carlevaro

Lattanzi

et al. 2012

Physica D: Nonlinear Phenomena

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A Wide-Angle Stokes Polarimeter for the Bootes Global Telescope Network. Optical and Mechanical Design

SYNIAVSKYI,

CASTRO-TIRADO,

IVANOV

et al. 2024

Kosm. nauka tehnol.

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We describe the imaging polarimeter EDIPO (Efficient & Dedicated wide-field Imaging Polarimeter) as a part of astronomical telescopes of the BOOTES (Burst Observer and Optical Transient Exploring System) network that is intended for the study of polarization features of the rapid processes of the gamma-ray bursts afterglow (Gamma-ray burst — GRB). The design of the polarimeter allows one to be installed on the network telescopes with a diameter of the main mirror up to 1.4 m. The EDIPO is designed to analyze the polarization parameters of linearly polarized light in the spectral range of 450—1000 nm. The polarization analyzer of the polarimeter does not contain moving elements and allows measurements of Stokes parameters I, Q, U of light in a 30'× 30' field of view simultaneously for one spectral band of the working spectral range. The optical part of the polarimeter was assembled and tested on a telescope with a mirror diameter of 1.2 m. The calibration approaches for the polarimeter-telescope system are considered.

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The magnetic field structure of the Small Magellanic Cloud

Cited by 2 publications

References 20 publications

Stability of a self-gravitating homogeneous resistive plasma

Stability of a self-gravitating homogeneous resistive plasma

A Wide-Angle Stokes Polarimeter for the Bootes Global Telescope Network. Optical and Mechanical Design

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