scholarly journals Oscillations and Mass Draining that Lead to a Sympathetic Eruption of a Quiescent Filament

2021 ◽  
Vol 923 (1) ◽  
pp. 74
Author(s):  
Jun Dai ◽  
Qingmin Zhang ◽  
Yanjie Zhang ◽  
Zhe Xu ◽  
Yingna Su ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Transverse Magnetic ◽  
Curvature Radius ◽  
Apparent Velocity ◽  
Velocity Amplitude ◽  
Enhance Mass ◽  
Transverse Oscillations ◽  
Quiescent Filament

Abstract In this paper, we present a multiwavelength analysis to mass draining and oscillations in a large quiescent filament prior to its successful eruption on 2015 April 28. The eruption of a smaller filament that was parallel and in close, ∼350″ proximity was observed to induce longitudinal oscillations and enhance mass draining within the filament of interest. The longitudinal oscillation with an amplitude of ∼25 Mm and ∼23 km s−1 underwent no damping during its observable cycle. Subsequently the slightly enhanced draining may have excited a eruption behind the limb, leading to a feedback that further enhanced the draining and induced simultaneous oscillations within the filament of interest. We find significant damping for these simultaneous oscillations, where the transverse oscillations proceeded with the amplitudes of ∼15 Mm and ∼14 km s−1, while the longitudinal oscillations involved a larger displacement and velocity amplitude (∼57 Mm, ∼43 km s−1). The second grouping of oscillations lasted for ∼2 cycles and had a similar period of ∼2 hr. From this, the curvature radius and transverse magnetic field strength of the magnetic dips supporting the filaments can be estimated to be ∼355 Mm and ≥34 G. The mass draining within the filament of interest lasted for ∼14 hr. The apparent velocity grew from ∼35 to ∼85 km s−1, with the transition being coincident with the occurrence of the oscillations. We conclude that two filament eruptions are sympathetic, i.e., the eruption of the quiescent filament was triggered by the eruption of the nearby smaller filament.

scholarly journals Simultaneous longitudinal and transverse oscillations in filament threads after a failed eruption

2019 ◽  
Vol 633 ◽  
pp. A12 ◽  
Author(s):  
Rakesh Mazumder ◽  
Vaibhav Pant ◽  
Manuel Luna ◽  
Dipankar Banerjee
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Large Amplitude ◽  
Large Scale ◽  
Radius Of Curvature ◽  
Solar Dynamics Observatory ◽  
Solar Prominences ◽  
Solar Dynamics ◽  
Transverse Oscillations

Context. Longitudinal and transverse oscillations are frequently observed in the solar prominences and/or filaments. These oscillations are excited by a large-scale shock wave, impulsive flares at one leg of the filament threads, or due to any low coronal eruptions. We report simultaneous longitudinal and transverse oscillations in the filament threads of a quiescent region filament. We observe a large filament in the northwest of the solar disk on July 6, 2017. On July 7, 2017, it starts rising around 13:00 UT. We then observe a failed eruption and subsequently the filament threads start to oscillate around 16:00 UT. Aims. We analyse oscillations in the threads of a filament and utilize seismology techniques to estimate magnetic field strength and length of filament threads. Methods. We placed horizontal and vertical artificial slits on the filament threads to capture the longitudinal and transverse oscillations of the threads. Data from Atmospheric Imaging Assembly onboard Solar Dynamics Observatory were used to detect the oscillations. Results. We find signatures of large-amplitude longitudinal oscillations (LALOs). We also detect damping in LALOs. In one thread of the filament, we observe large-amplitude transverse oscillations (LATOs). Using the pendulum model, we estimate the lower limit of magnetic field strength and radius of curvature from the observed parameter of LALOs. Conclusions. We show the co-existence of two different wave modes in the same filament threads. We estimate magnetic field from LALOs and suggest a possible range of the length of the filament threads using LATOs.

scholarly journals The connection of fine-structure photospheric features in active regions with magnetic fields

1968 ◽  
Vol 35 ◽  
pp. 201-201
Author(s):  
N. V. Steshenko
Keyword(s):  
Magnetic Field ◽  
Fine Structure ◽  
High Resolution ◽  
Magnetic Fields ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Active Regions ◽  
Transverse Magnetic ◽  
List Type ◽  
The Magnetic Field

1.The fine structure of the proton sunspot group of July 4–8, 1966 was studied on the basis of high-resolution heliograms. The comparison of the orientation between penumbral filaments and the transverse magnetic fields (observed by A.B. Severny and T.T. Tsap) shows that the direction of the filaments coincides in general with that of the magnetic field.2.Measurements of the magnetic fields of smallest pores (1·5″-2″) showed that the pores are always connected with strong magnetic field (in average 1400 gauss), which is localized at the same small area as the pore.3.Magnetic fields of faculae are concentrated in small elements with the dimension not exceeding 1·5″-3″. Magnetic-field strength H|| of about 45% of facular granules is within the limits of photographic measuring errors (approximately 25 gauss). For a quarter of all facular granules the strength H|| is from 25–50 gauss; about 30% of facular granules have H|| > 50 gauss, and sometimes there appear faculae with field strength of about 200 gauss. The magnetic-field strength of facular granules, which are found directly above spots, is 10–20 times less than the field strength of spots. This field is 80–210 gauss only.4.All observational data mentioned above show that the appearance of the fine-structure features in active regions is directly connected with the fine structure of magnetic field of different strength and different orientation. The study of high-resolution heliograms gives additional information about the fine structure of the magnetic field.

On the Configuration of the Magnetic Field of β CrB

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.

2D analysis of magnetic field strength in GO SiFe steel sheets

1998 ◽  
Vol 08 (PR2) ◽  
pp. Pr2-579-Pr2-582 ◽  
Author(s):  
S. Tumanski ◽  
M. Stabrowski
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Steel Sheets

MAGNETIC FIELD, PRESSURE AND TEMPERATURE DEPENDENT OPTICAL PROPERTIES IN A GaAs 9.0 P 1.0 QUANTUM DOT

2014 ◽  
Vol 6 (2) ◽  
pp. 1178-1190
Author(s):  
A. JOHN PETER ◽  
Ada Vinolin
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Quantum Dot ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Photon Energy ◽  
Nonlinear Optical ◽  
Binding Energies ◽  
Nonlinear Optical Properties ◽  
Optical Rectification

Simultaneous effects of magnetic field, pressure and temperature on the exciton binding energies are found in a 9.0 1.0 6.0 4.0 GaAs P / GaAs P quantum dot. Numerical calculations are carried out taking into consideration of spatial confinement effect. The cylindrical system is taken in the present problem with the strain effects. The electronic properties and the optical properties are found with the combined effects of magnetic field strength, hydrostatic pressure and temperature values. The exciton binding energies and the nonlinear optical properties are carried out taking into consideration of geometrical confinement and the external perturbations.Compact density approach is employed to obtain the nonlinear optical properties. The optical rectification coefficient is obtained with the photon energy in the presence of pressure, temperature and external magnetic field strength. Pressure and temperature dependence on nonlinear optical susceptibilities of generation of second and third order harmonics as a function of incident photon energy are brought out in the influence of magnetic field strength. The result shows that the electronic and nonlinear optical properties are significantly modified by the applications of external perturbations in a 9.0 1.0 6.0 4.0 GaAs P / GaAs P quantum dot.

Magnetic field strength dependence of chemical shift artifacts

1988 ◽  
Vol 12 (2) ◽  
pp. 89-96 ◽  
Author(s):  
R. Lufkin ◽  
M. Anselmo ◽  
J. Crues ◽  
W. Smoker ◽  
W. Hanafee
Keyword(s):  
Magnetic Field ◽  
Chemical Shift ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Strength Dependence

scholarly journals Heat Transfer Study of the Ferrofluid Flow in a Vertical Annular Cylindrical Duct under the Influence of a Transverse Magnetic Field

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 120
Author(s):  
Panteleimon Bakalis ◽  
Polycarpos Papadopoulos ◽  
Panayiotis Vafeas
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Field Strength ◽  
Circular Cross Section ◽  
Transverse Magnetic ◽  
Uniform Grid ◽  
Volumetric Concentration ◽  
Flow And Heat Transfer ◽  
Axial Pressure Gradient ◽  
Transfer Study

We studied the laminar fully developed ferrofluid flow and heat transfer phenomena of an otherwise magnetic fluid into a vertical annular duct of circular cross-section and uniform temperatures on walls which were subjected to a transverse external magnetic field. A computational algorithm was used, which coupled the continuity, momentum, energy, magnetization and Maxwell’s equations, accompanied by the appropriate conditions, using the continuity–vorticity–pressure (C.V.P.) method and a non-uniform grid. The results were obtained for different values of field strength and particles’ volumetric concentration, wherein the effects of the magnetic field on the ferrofluid flow and the temperature are revealed. It is shown that the axial velocity distribution is highly affected by the field strength and the volumetric concentration, the axial pressure gradient depends almost linearly on the field strength, while the heat transfer significantly increases due to the generated secondary flow.

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