On the continuum intensity-magnetic field relation along the decay phase of sunspots

1990 ◽  
Vol 170 (1-2) ◽  
pp. 75-79 ◽  
Author(s):  
V. Mart�nez Pillet ◽  
M. V�zquez
Keyword(s):  
Magnetic Field ◽  
Decay Phase ◽  
Field Relation ◽  
Continuum Intensity ◽  
Intensity Magnetic Field ◽  
The Continuum

scholarly journals The Continuum Intensity Magnetic Field Relation in Sunspot Umbrae

1993 ◽  
Vol 141 ◽  
pp. 60-62
Author(s):  
V. Martínez Pillet ◽  
M. Vázquez
Keyword(s):  
Magnetic Field ◽  
Linear Relation ◽  
Field Relation ◽  
Continuum Intensity ◽  
Intensity Magnetic Field ◽  
The Magnetic Field ◽  
The Continuum

AbstractThe local relation between the temperature and the magnetic field in sunspot umbrae is studied. Sunspots with different sizes have been studied and we found a linear relation between temperature and the square of the magnetic field. We have found also a dependence between the minimum continuum intensity and the size of the spot.

scholarly journals The continuum intensity as a function of magnetic field

2011 ◽  
Vol 531 ◽  
pp. A112 ◽  
Author(s):  
P. Kobel ◽  
S. K. Solanki ◽  
J. M. Borrero
Keyword(s):  
Magnetic Field ◽  
Continuum Intensity ◽  
The Continuum

scholarly journals No universal connection between the vertical magnetic field and the umbra-penumbra boundary in sunspots

2020 ◽  
Vol 639 ◽  
pp. A106
Author(s):  
B. Löptien ◽  
A. Lagg ◽  
M. van Noort ◽  
S. K. Solanki
Keyword(s):  
Magnetic Field ◽  
Statistical Analysis ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Filling Factor ◽  
Spot Size ◽  
Vertical Magnetic Field ◽  
Continuum Intensity ◽  
The Mean ◽  
The Continuum

Context. It has been reported that the boundary between the umbra and the penumbra of sunspots occurs at a canonical value of the strength of the vertical magnetic field, independently of the size of the spot. This critical field strength is interpreted to be the threshold for the onset of magnetoconvection. Aims. Here we investigate the reasons why this criterion, also called the Jurčák criterion in the literature, does not always identify the boundary between the umbra and the penumbra. Methods. We performed a statistical analysis of 23 sunspots observed with Hinode/SOT. We compared the properties of the continuum intensity and the vertical magnetic field between filaments and spines and how they vary between spots of different sizes. Results. We find that the inner boundary of the penumbra is not related to a universal value of the vertical magnetic field. The properties of spines and filaments vary between spots of different sizes. Both components are darker in larger spots and the spines exhibit a stronger vertical magnetic field. These variations of the properties of filaments and spines with the spot size are also the reason for the reported invariance in the averaged vertical magnetic field at 50% of the mean continuum intensity. Conclusions. The formation of filaments and the onset of magnetoconvection are not related to a canonical value of the strength of the vertical magnetic field. The seemingly unique magnetic field strength is rather an effect of the filling factor of spines and penumbral filaments.

scholarly journals Long quasi-periodic oscillations of the faculae and pores

2019 ◽  
Vol 627 ◽  
pp. A10 ◽  
Author(s):  
A. Riehokainen ◽  
P. Strekalova ◽  
A. Solov’ev ◽  
V. Smirnova ◽  
I. Zhivanovich ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Stable Phase ◽  
Small Scale ◽  
Solar Photosphere ◽  
Periodic Oscillations ◽  
Magnetic Structures ◽  
Long Period ◽  
Continuum Intensity ◽  
Structurally Stable ◽  
The Continuum

Aims. The main goal of this work is to analyze the structural and temporal evolution of small-scale magnetic structures (SSMSs) observed in the solar atmosphere, such as solitary faculae and pores, and reveal long quasi-periodic oscillations of these structures. Methods. The statistical method of regression analysis and the wavelet transform were used to obtain the periods of oscillations and dependences between the parameters of magnetic structures and periods of oscillations. Results. Long-period oscillations with periods in the interval of 18−260 min are found for the structurally stable phase of SSMSs at the level of the solar photosphere. These long-period oscillations were interpreted as natural oscillations of the structurally stable long-lived magnetic structures around their equilibrium position. These oscillations, which are of similar nature, are observed in the chromospheric bright formations associated with photospheric SSMSs. Dependences between the magnetic field and the continuum intensity of the facula elements were found. It is shown that the continuum intensity of a SSMS decreases when its magnetic field increases.

scholarly journals The continuum intensity as a function of magnetic field

2012 ◽  
Vol 542 ◽  
pp. A96 ◽  
Author(s):  
P. Kobel ◽  
S. K. Solanki ◽  
J. M. Borrero
Keyword(s):  
Magnetic Field ◽  
Continuum Intensity ◽  
The Continuum

scholarly journals Active angular tuning and switching of Brewster quasi bound states in the continuum in magneto-optic metasurfaces

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Diego R. Abujetas ◽  
Nuno de Sousa ◽  
Antonio García-Martín ◽  
José M. Llorens ◽  
José A. Sánchez-Gil
Keyword(s):  
Magnetic Field ◽  
Magnetic Dipole ◽  
Bound States ◽  
Electromagnetic Spectrum ◽  
Resonant Modes ◽  
Out Of Plane ◽  
Q Factors ◽  
The Impact ◽  
The Continuum ◽  
Magneto Optic

Abstract Bound states in the continuum (BICs) emerge throughout physics as leaky/resonant modes that remain, however, highly localized. They have attracted much attention in photonics, and especially in metasurfaces. One of their most outstanding features is their divergent Q-factors, indeed arbitrarily large upon approaching the BIC condition (quasi-BICs). Here, we investigate how to tune quasi-BICs in magneto-optic (MO) all-dielectric metasurfaces. The impact of the applied magnetic field in the BIC parameter space is revealed for a metasurface consisting of lossless semiconductor spheres with MO response. Through our coupled electric/magnetic dipole formulation, the MO activity is found to manifest itself through the interference of the out-of-plane electric/magnetic dipole resonances with the (MO-induced) in-plane magnetic/electric dipole, leading to a rich, magnetically tuned quasi-BIC phenomenology, resembling the behavior of Brewster quasi-BICs for tilted vertical-dipole resonant metasurfaces. Such resemblance underlies our proposed design for a fast MO switch of a Brewster quasi-BIC by simply reversing the driving magnetic field. This MO-active BIC behavior is further confirmed in the optical regime for a realistic Bi:YIG nanodisk metasurface through numerical calculations. Our results present various mechanisms to magneto-optically manipulate BICs and quasi-BICs, which could be exploited throughout the electromagnetic spectrum with applications in lasing, filtering, and sensing.

Changes in the Antibacterial Activity of Benzylpenicillin Exposed to a Pulsed High-Intensity Magnetic Field

BIOPHYSICS ◽  
2019 ◽  
Vol 64 (2) ◽  
pp. 214-223
Author(s):  
V. A. Glushchenkov ◽  
T. I. Vasilyeva ◽  
P. P. Purigin ◽  
I. A. Belyaeva ◽  
N. A. Rodenko ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Antibacterial Activity ◽  
High Intensity ◽  
Intensity Magnetic Field

Chronic exposure to low-intensity magnetic field improves acquisition and maintenance of memory

Neuroreport ◽  
2008 ◽  
Vol 19 (5) ◽  
pp. 549-552 ◽  
Author(s):  
Tongtong Liu ◽  
Sheng Wang ◽  
Lihua He ◽  
Kangping Ye
Keyword(s):  
Magnetic Field ◽  
Chronic Exposure ◽  
Low Intensity ◽  
Intensity Magnetic Field
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