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Related papers: MHD Turbulence as a Foreground for CMB Studies

200 papers

Density is the turbulence statistics that is most readily available from observations. Different regimes of turbulence correspond to different density spectra. For instance, the viscosity-damped regime of MHD turbulence relevant, for…

Astrophysics · Physics 2008-01-03 A. Lazarian , G. Kowal , A. Beresnyak

The magnetic structure in the Galactic disk, the Galactic center and the Galactic halo can be delineated more clearly than ever before. In the Galactic disk, the magnetic structure has been revealed by starlight polarization within 2 or 3…

Astrophysics of Galaxies · Physics 2009-11-13 J. L. Han

We derive the angular power spectra of intensity and polarization of Galactic synchrotron emission in the range 36 < l < 10^3 from the Parkes survey mapping the southern Galactic plane at 2.4 GHz. The polarization spectra of both electric…

Astrophysics · Physics 2009-10-31 M. Tucci , E. Carretti , S. Cecchini , R. Fabbri , M. Orsini , E. Pierpaoli

When present, extended disks of neutral hydrogen around spiral galaxies show a remarkably uniform velocity dispersion of approx 6 km/s. Since stellar winds and supernovae are largely absent in such regions, neither the magnitude nor the…

Astrophysics · Physics 2009-10-30 J. A. Sellwood , S. A. Balbus

Using magnetohydrodynamic simulations of fluctuation dynamos, we perform broad-bandwidth synthetic observations to investigate the properties of polarized synchrotron emission and the role that Faraday rotation plays in inferring the…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-25 Sharanya Sur , Aritra Basu , Kandaswamy Subramanian

Possible detection of signatures of structure formation at the end of the 'dark age' epoch (z~40-20) is examined. We discuss the spectral-spatial fluctuations in the CMBR temperature produced by elastic resonant scattering of CMBR photons…

Astrophysics · Physics 2008-11-26 R. Nunez-Lopez , A. Lipovka , V. Avila-Reese

Recent 21 cm radio observations of H$_I$ regions in the Small Magellanic Cloud, have revealed spatial power spectra of the intensity, which are quite similar in shape to those previously deduced for the Galaxy. The similarity, in spite the…

Astrophysics · Physics 2016-08-30 Itzhak Goldman

We will in this paper report on suggestive similarities between density fluctuation power versus wavenumber on small (mm) and large (Mpc) scales. The small scale measurements were made in fusion plasmas and compared to predictions from…

Plasma Physics · Physics 2016-12-28 N. P. Basse

Magnetohydrodynamic (MHD) instabilities can play an important role in the structure and dynamics of the pulsar magnetosphere. We consider the instabilitycaused by differential rotation that is suggested by many theoretical models. Stability…

High Energy Astrophysical Phenomena · Physics 2015-06-04 V. Urpin

Macroscopic evolution of relativistic charged matter with chirality imbalance is described by the chiral magnetohydrodynamics (chiral MHD). One such astrophysical system is high-density lepton matter in core-collapse supernovae where the…

High Energy Astrophysical Phenomena · Physics 2018-10-24 Youhei Masada , Kei Kotake , Tomoya Takiwaki , Naoki Yamamoto

We demostrate that the measurement of fluctuations of polarization due to the galactic interstellar scintillations may be used to study the structure of the radiation field at compact radio sources. We develop a mathematical formalism and…

Astrophysics · Physics 2009-10-31 Mikhail V. Medvedev

Solar wind magnetic fluctuation spectra exhibit a significant power law steepening at frequencies f>1Hz. The origin of this multi-scaling is investigated through dispersive Hall magnetohydrodynamics. We perform three-dimensional numerical…

Astrophysics · Physics 2008-11-26 S. Galtier , E. Buchlin

When magnetic energy density is much larger than that of matter, as in pulsar/black hole magnetospheres, the medium becomes force-free and we need relativity to describe it. As in non-relativistic magnetohydrodynamics (MHD), Alfv\'enic MHD…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Jungyeon Cho , A. Lazarian

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of cosmic ray transport. In this paper we use recently obtained scaling laws for MHD modes to obtain the scattering frequency for…

Astrophysics · Physics 2009-11-10 Huirong Yan , A. Lazarian

A variety of studies of magnetised plasma turbulence invoke theories for the advection of a passive scalar by turbulent fluctuations. Examples include modelling the electron density fluctuations in the interstellar medium, understanding the…

Plasma Physics · Physics 2015-06-23 Joanne Mason , Stanislav Boldyrev , Fausto Cattaneo , Jean Carlos Perez

We present a three-dimensional model of polarised galactic dust emission that takes into account the variation of the dust density, spectral index and temperature along the line of sight, and contains randomly generated small scale…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-31 Ginés Martínez-Solaeche , Ata Karakci , Jacques Delabrouille

We investigate the steepening of the magnetic fluctuation power law spectra observed in the inner solar wind for frequencies higher than 0.5 Hz. This high frequency part of the spectrum may be attributed to dispersive nonlinear processes.…

Space Physics · Physics 2009-11-13 S. Galtier

We investigate properties of plasma turbulence from magneto-hydrodynamic (MHD) to sub-ion scales by means of two-dimensional, high-resolution hybrid particle-in-cell simulations. We impose an initial ambient magnetic field, perpendicular to…

Solar and Stellar Astrophysics · Physics 2015-10-14 Luca Franci , Simone Landi , Lorenzo Matteini , Andrea Verdini , Petr Hellinger

We review present understanding of Galactic free-free emission and its possible importance to CMB fluctuation measurements. Current results, from both ``direct'' observations in the microwave band and from H$\alpha$ studies, suggest that…

Astrophysics · Physics 2016-08-30 J. G. Bartlett , P. Amram

Spectral properties of a fully compressible solar wind Hall Magnetohydrodynamic plasma are investigated by means of time dependent three dimensional Hall MHD simulations. Our simulations, in agreement with spacecraft data, identify a…

Space Physics · Physics 2015-05-14 Dastgeer Shaikh , G. P. Zank