Multifractal structure of the large-scale heliospheric magnetic field strength fluctuations near 85AU

Abstract. During 2002, the Voyager 1 spacecraft was in the heliosphere between 83.4 and 85.9AU (1AU is the mean distance from the Sun to Earth) at 34° N heliographic latitude. The magnetic field strength profile observed in this region had a multifractal structure in the range of scales from 2 to 16 days. The multifractal spectrum observed near 85AU is similar to that observed near 40AU, indicating relatively little evolution of the multifractal structure of the magnetic field with increasing distance in the distant heliosphere in the epoch near solar maximum.

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Some comments about correlations between magnetic field and velocity, magnetic field and line intensity in the undisturbed photosphere

Symposium - International Astronomical Union ◽

10.1017/s0074180900021586 ◽

1968 ◽

Vol 35 ◽

pp. 236-239

Author(s):

G. Y. Vassilyeva ◽

A. K. Tchandaev

Keyword(s):

Magnetic Field ◽

Velocity Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Correlation Functions ◽

Cross Correlation ◽

Absolute Value ◽

Field Recordings ◽

The Mean ◽

The Magnetic Field

Test cross-correlation functions between the magnetic field recordings and the sight-line velocity recordings with East and West relative lag for two regions near the centre of the disk have been computed. We have also found the deviations of the absolute value of the magnetic-field strength |H| from the mean absolute value of magnetic-field strength |H̄| for the whole region. The same procedure for the velocity field has been made. The cross-correlation functions for these deviations have also been computed (Figure 1).

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The magnetic field strength in the Large Magellanic Cloud

Symposium - International Astronomical Union ◽

10.1017/s0074180900200107 ◽

1991 ◽

Vol 148 ◽

pp. 101-102

Author(s):

M.E. Costa ◽

P. M. McCulloch ◽

P. A. Hamilton

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Large Magellanic Cloud ◽

Radio Pulsar ◽

Line Of Sight ◽

The Sun ◽

A Value ◽

Rotation Measure ◽

The Magnetic Field

We have measured a value of 4±5m--2rad for the rotation measure of the radio pulsar PSR0529-66 in the LMC and, after allowing for the dispersion and rotation measures of our Galaxy on the pulsar's line of sight, we deduce that the magnetic field strength in the LMC is in the range 0 to 5μGauss oriented away from the Sun.

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The magnetic field of the evolved star W43A

Proceedings of the International Astronomical Union ◽

10.1017/s174392130903021x ◽

2008 ◽

Vol 4 (S259) ◽

pp. 109-110

Author(s):

Nikta Amiri ◽

Wouter Vlemmings ◽

Huib Jan van Langevelde

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Circular Polarization ◽

Magnetic Field Strength ◽

Large Scale ◽

Zeeman Splitting ◽

Density Region ◽

Evolved Stars ◽

Large Scale Magnetic Field ◽

The Magnetic Field

AbstractPlanetary nebulae (PNe) often show large departures from spherical symmetry. The origin and development of these asymmetries is not clearly understood. The most striking structures are the highly collimated jets that are already observed in a number of evolved stars before they enter the PN phase. The aim of this project is to observe the Zeeman splitting of the OH maser of the W43A star and determine the magnetic field strength in the low density region. The 1612 MHz OH masers of W43A were observed with MERLIN to measure the circular polarization due to the Zeeman splitting of 1612 OH masers in the envelope of the evolved star W43A. We measured the circular polarization of the strongest 1612 OH masers of W43A and found a magnetic field strength of ~100μG. The magnetic field measured at the location of W43A OH masers confirms that a large scale magnetic field is present in W43A, which likely plays a role in collimating the jet.

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Magnetic Fields in Molecular Clouds

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311017601 ◽

2010 ◽

Vol 6 (S271) ◽

pp. 187-196 ◽

Cited By ~ 1

Author(s):

Paolo Padoan ◽

Tuomas Lunttila ◽

Mika Juvela ◽

Åke Nordlund ◽

David Collins ◽

...

Keyword(s):

Magnetic Field ◽

Star Formation ◽

Field Strength ◽

Magnetic Field Strength ◽

Molecular Clouds ◽

Large Scale ◽

Small Scale ◽

Mhd Turbulence ◽

Turbulence Simulation ◽

The Magnetic Field

AbstractSupersonic magneto-hydrodynamic (MHD) turbulence in molecular clouds (MCs) plays an important role in the process of star formation. The effect of the turbulence on the cloud fragmentation process depends on the magnetic field strength. In this work we discuss the idea that the turbulence is super-Alfvénic, at least with respect to the cloud mean magnetic field. We argue that MCs are likely to be born super-Alfvénic. We then support this scenario based on a recent simulation of the large-scale warm interstellar medium turbulence. Using small-scale isothermal MHD turbulence simulation, we also show that MCs may remain super-Alfvénic even with respect to their rms magnetic field strength, amplified by the turbulence. Finally, we briefly discuss the comparison with the observations, suggesting that super-Alfvénic turbulence successfully reproduces the Zeeman measurements of the magnetic field strength in dense MC clouds.

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Fluctuations of the magnetic-field strength of sunspots within one day

Symposium - International Astronomical Union ◽

10.1017/s0074180900021549 ◽

1968 ◽

Vol 35 ◽

pp. 214-214

Author(s):

H. Künzel

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

General Tendency ◽

Mean Error ◽

The Mean ◽

Short Time ◽

The Magnetic Field ◽

Field Strengths

In the period of May-June 1965, the magnetic-field strengths of twenty sunspots were measured in order to investigate fluctuations within one day. The results of spectrograms, which were taken in the interval of one hour, are given in graphs. The mean error of one value has the size of ± 169 gauss. The graphs show the general tendency in the behaviour of field strength. Fluctuations of magnetic-field strength up to 800 gauss within a few hours were found. The short-time fluctuations shown in the graphs are mostly smaller than the mean error and therefore probably not real.For more details see Astron. Nachr., 289 (1967), 233.

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Granular cells in the presence of magnetic field

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317000126 ◽

2016 ◽

Vol 12 (S327) ◽

pp. 34-39

Author(s):

J. Jurčák ◽

B. Lemmerer ◽

M. van Noort

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Statistical Study ◽

Line Of Sight ◽

Active Region Noaa ◽

Granular Cells ◽

The Mean ◽

Convective Cells ◽

The Magnetic Field

AbstractWe present a statistical study of the dependencies of the shapes and sizes of the photospheric convective cells on the magnetic field properties. This analysis is based on a 2.5 hour long SST observations of active region NOAA 11768. We have blue continuum images taken with a cadence of 5.6 sec that are used for segmentation of individual granules and 270 maps of spectropolarimetric CRISP data allowing us to determine the properties of the magnetic field along with the line-of-sight velocities. The sizes and shapes of the granular cells are dependent on the the magnetic field strength, where the granules tend to be smaller in regions with stronger magnetic field. In the presence of highly inclined magnetic fields, the eccentricity of granules is high and we do not observe symmetric granules in these regions. The mean up-flow velocities in granules as well as the granules intensities decrease with increasing magnetic field strength.

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On the Configuration of the Magnetic Field of β CrB

International Astronomical Union Colloquium ◽

10.1017/s0252921100080933 ◽

1976 ◽

Vol 32 ◽

pp. 613-622

Author(s):

I.A. Aslanov ◽

Yu.S. Rustamov

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Radial Velocity ◽

Magnetic Field Strength ◽

Complex Shape ◽

Rotation Period ◽

Field Variation ◽

Magnetic Field Variation ◽

Secular Variations ◽

The Magnetic Field

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.

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The effects of magnetic field strength on the properties of wind generated from hot accretion flow

Astronomy and Astrophysics ◽

10.1051/0004-6361/201832985 ◽

2018 ◽

Vol 615 ◽

pp. A35 ◽

Cited By ~ 10

Author(s):

De-Fu Bu ◽

Amin Mosallanezhad

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Pressure Gradient ◽

Magnetic Field Strength ◽

Magnetic Pressure ◽

Gas Pressure ◽

Accretion Flow ◽

Accretion Flows ◽

Black Hole Accretion ◽

The Magnetic Field

Context. Observations indicate that wind can be generated in hot accretion flow. Wind generated from weakly magnetized accretion flow has been studied. However, the properties of wind generated from strongly magnetized hot accretion flow have not been studied. Aims. In this paper, we study the properties of wind generated from both weakly and strongly magnetized accretion flow. We focus on how the magnetic field strength affects the wind properties. Methods. We solve steady-state two-dimensional magnetohydrodynamic equations of black hole accretion in the presence of a largescale magnetic field. We assume self-similarity in radial direction. The magnetic field is assumed to be evenly symmetric with the equatorial plane. Results. We find that wind exists in both weakly and strongly magnetized accretion flows. When the magnetic field is weak (magnetic pressure is more than two orders of magnitude smaller than gas pressure), wind is driven by gas pressure gradient and centrifugal forces. When the magnetic field is strong (magnetic pressure is slightly smaller than gas pressure), wind is driven by gas pressure gradient and magnetic pressure gradient forces. The power of wind in the strongly magnetized case is just slightly larger than that in the weakly magnetized case. The power of wind lies in a range PW ~ 10−4–10−3 Ṁinc2, with Ṁin and c being mass inflow rate and speed of light, respectively. The possible role of wind in active galactic nuclei feedback is briefly discussed.

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COMPARISON OF CARDIAC MAGNETIC FIELD DISTRIBUTIONS DURING DEPOLARIZATION AND REPOLARIZATION

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127403008971 ◽

2003 ◽

Vol 13 (12) ◽

pp. 3783-3789 ◽

Cited By ~ 4

Author(s):

F. E. SMITH ◽

P. LANGLEY ◽

L. TRAHMS ◽

U. STEINHOFF ◽

J. P. BOURKE ◽

...

Keyword(s):

Magnetic Field ◽

Field Strength ◽

Magnetic Field Strength ◽

Field Distribution ◽

Normal Subjects ◽

The Body ◽

Magnetic Field Distribution ◽

T Wave ◽

High Magnetic Field Strength ◽

The Magnetic Field

Multichannel magnetocardiography measures the magnetic field distribution of the human heart noninvasively from many sites over the body surface. Multichannel magnetocardiogram (MCG) analysis enables regional temporal differences in the distribution of cardiac magnetic field strength during depolarization and repolarization to be identified, allowing estimation of the global and local inhomogeneity of the cardiac activation process. The aim of this study was to compare the spatial distribution of cardiac magnetic field strength during ventricular depolarization and repolarization in both normal subjects and patients with cardiac abnormalities, obtaining amplitude measurements by magnetocardiography. MCGs were recorded at 49 sites over the heart from three normal subjects and two patients with inverted T-wave conditions. The magnetic field intensity during depolarization and repolarization was measured automatically for each channel and displayed spatially as contour maps. A Pearson correlation was used to determine the spatial relationship between the variables. For normal subjects, magnetic field strength maps during depolarization (R-wave) showed two asymmetric regions of magnetic field strength with a high positive value in the lower half of the chest and a high negative value above this. The regions of high R-wave amplitude corresponded spatially to concentrated asymmetric regions of high magnetic field strength during repolarization (T-wave). Pearson-r correlation coefficients of 0.7 (p<0.01), 0.8 (p<0.01) and 0.9 (p<0.01) were obtained from this analysis for the three normal subjects. A negative correlation coefficient of -0.7 (p<0.01) was obtained for one of the subjects with inverted T-wave abnormalities, suggesting similar but inverted magnetic field and current distributions to normal subjects. Even with the high correlation values in these four subjects, the MCG was able to identify differences in the distribution of magnetic field strength, with a shift in the T-wave relative to the R-wave. The measurement of cardiac magnetic field distribution during depolarization and repolarization of normal subjects and patients with clinical abnormalities should enable the improvement of theoretical models for the explanation of the cardiac depolarization and repolarization processes.

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