scholarly journals On the magnetic-field configuration in sunspots

1968 ◽  
Vol 35 ◽  
pp. 202-210
Author(s):  
O. Kjeldseth Moe
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Solar Disk ◽  
Field Configuration ◽  
Solar Observatory ◽  
Line Profiles ◽  
Magnetic Field Configuration ◽  
The Magnetic Field

During 1963–67 observations of the magnetic fields in sunspots have been obtained at the Oslo Solar Observatory. For the largest spots the detailed distribution of the magnetic-field strength is found. Based on calculations of line profiles made by the author (Kjeldseth Moe, 1967) also the direction of the magnetic field is derived. Observations of the magnetic field of the same spot at several positions on the solar disk give further information regarding the magnetic-field configuration. Our results are in fair agreement with those of Bumba (1962).

Analysis of bipolar outflow parameters, magnetic fields and maser activity relationship in EGO sources

2017 ◽  
Vol 13 (S336) ◽  
pp. 63-64
Author(s):  
O. S. Bayandina ◽  
I. E. Val’tts ◽  
P. Colom ◽  
S. E. Kurtz ◽  
G. M. Rudnitskij ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Spectral Resolution ◽  
Field Configuration ◽  
Magnetic Field Configuration ◽  
Bipolar Outflow ◽  
Inner Region ◽  
Disk Area

AbstractThe interferometric and single-dish observations of the Extended Green Objects sample have been carried out in order to check the possible common pumping mechanism of class I methanol maser (cIMM) and OH(1720 MHz) maser and their identification with a front of bipolar outflow as a source of interstellar shock stimulating collisional pumping of the molecules. High spatial and spectral resolution observations of OH masers allow us to investigate structure, kinematics, and magnetic field configuration of the inner region of the source, i.e., the outflow ejection region. Analysis of magnetic field strength in a disk area is crucial to understanding of the outflow origin.

scholarly journals The Two Component Magnetic Field of the Galaxy

1990 ◽  
Vol 140 ◽  
pp. 54-54
Author(s):  
R.R. Andreassian ◽  
A.N. Makarov
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Configuration ◽  
Radio Sources ◽  
Magnetic Field Configuration ◽  
Spiral Arms ◽  
Two Component ◽  
The Galaxy ◽  
The Magnetic Field ◽  
Spiral Arm

The present paper is devoted to a study of the magnetic field configuration of our Galaxy based on Faraday rotation measures (RM) of 185 pulsars and 802 extragalactic radio sources. RM data of pulsars located near the plane of the Galaxy are used for the study of magnetic fields in neighbouring spiral arms. For the distribution of spiral arms the well-known model of Georgelin and Georgelin (1976) is used. The calculations show (for details see Andreassian and Makarov, 1987, 1989) that in the Perseus spiral arm and the local Orion arm the magnetic fields have approximately the same directions (lo;bo) ≈ (80°;0°), while in the Sagittarius-Carina arm the magnetic field has an opposite direction.

A portable apparatus for measuring the magnetic field strength in an electromagnetic wave

1931 ◽  
Vol 27 (3) ◽  
pp. 481-489
Author(s):  
L. G. Vedy ◽  
A. F. Wilkins
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Wave ◽  
Magnetic Fields ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Special Means ◽  
Portable Apparatus ◽  
The Magnetic Field ◽  
Field Strengths

A portable apparatus is described which is capable of measuring directly, by means of a loop aerial, the magnetic field in an electromagnetic wave. Accurate measurements are possible of magnetic fields corresponding to field strengths of 0·2 millivolts per metre. Special means of providing small known calibrating E. M. F. S are described. The apparatus can be used to measure signals over the range 6 microvolts to 300 millivolts. Used in conjunction with a small portable vertical aerial, field strengths down to 2 microvolts per metre can be measured.

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.

scholarly journals PENGARUH MEDAN MAGNET TERHADAP DIAMETER PERKECAMBAHAN KACANG HIJAU

2020 ◽  
Vol 5 (1) ◽  
pp. 66-70
Author(s):  
Aditya Vethra Prasetyo
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Green Bean ◽  
Green Beans ◽  
Bean Sprout ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
The Magnetic Field

Abstrak Penelitian yang dilakukan berjudul “Pengaruh Medan Magnet  Terhadap Diameter Perkecambahan Kacang Hijau”. Penelitian ini bertujuan untuk mengetahui pengaruh medan magnet terhadap diameter perkecambahan kacang hijau. Penelitian ini disusun dalam Rancangan Acak Lengkap (RAL) dengan satu faktor, yaitu kuat medan magnet dalam waktu yang sama yang terdiri dari kontrol (0 mT), 5,3 mT, 10,7 mT, 16,1 mT, 21,5 mT. Parameter yang diukur adalah diameter batang kecambah kacang hijau. Data dianalisis ragam dilanjutkan dengan uji DMRT pada taraf α = 5%. Hasil penelitian menunjukkan bahwa pemaparan medan magnet  mempengaruhi diameter batang kecambah kacang hijau. Perlakuan yang menyebabkan perkembangan diameter batang terbesar adalah 21,5 mT. Kata kunci: kacang hijau, medan magnet, diameter Abstract The study was conducted entitled "The Effect of Magnetic Fields on the Diameter of Green Bean Germination". This study aims to determine the effect of the magnetic field on the diameter of green bean germination. This research was arranged in a Completely Randomized Design (CRD) with one factor, namely magnetic field strength at the same time consisting of controls (0 mT), 5.3 mT, 10.7 mT, 16.1 mT, 21.5 mT . The parameter measured is the diameter of the green bean sprout stem. Data were analyzed by continued variance with DMRT test at α = 5%. The results showed that exposure to the magnetic field affected the diameter of the green bean sprout stem. The treatment that caused the largest stem diameter development was 21.5 mT. Keywords: green beans, magnetic field, diameter

scholarly journals Inference of the chromospheric magnetic field configuration of solar plage using the Ca II 8542 Å line

2020 ◽  
Vol 644 ◽  
pp. A43 ◽  
Author(s):  
A. G. M. Pietrow ◽  
D. Kiselman ◽  
J. de la Cruz Rodríguez ◽  
C. J. Díaz Baso ◽  
A. Pastor Yabar ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Numerical Models ◽  
Signal To Noise Ratio ◽  
Field Configuration ◽  
Magnetic Field Configuration ◽  
Signal To Noise ◽  
Plage Region ◽  
Noise Ratio ◽  
The Magnetic Field

Context. It has so far proven impossible to reproduce all aspects of the solar plage chromosphere in quasi-realistic numerical models. The magnetic field configuration in the lower atmosphere is one of the few free parameters in such simulations. The literature only offers proxy-based estimates of the field strength, as it is difficult to obtain observational constraints in this region. Sufficiently sensitive spectro-polarimetric measurements require a high signal-to-noise ratio, spectral resolution, and cadence, which are at the limit of current capabilities. Aims. We use critically sampled spectro-polarimetric observations of the Ca II 8542 Å line obtained with the CRISP instrument of the Swedish 1-m Solar Telescope to study the strength and inclination of the chromospheric magnetic field of a plage region. This will provide direct physics-based estimates of these values, which could aid modelers to put constraints on plage models. Methods. We increased the signal-to-noise ratio of the data by applying several methods including deep learning and PCA. We estimated the noise level to be 1 × 10−3 Ic. We then used STiC, a non-local thermodynamic equilibrium inversion code to infer the atmospheric structure and magnetic field pixel by pixel. Results. We are able to infer the magnetic field strength and inclination for a plage region and for fibrils in the surrounding canopy. In the plage we report an absolute field strength of |B| = 440 ± 90 G, with an inclination of 10° ±16° with respect to the local vertical. This value for |B| is roughly double of what was reported previously, while the inclination matches previous studies done in the photosphere. In the fibrillar region we found |B| = 300 ± 50 G, with an inclination of 50° ±13°.

scholarly journals Eindimensionale Plasmaströmung in gekreuzten elektrischen und magnetischen Feldern

1965 ◽  
Vol 20 (8) ◽  
pp. 1019-1026 ◽  
Author(s):  
E. Rebhan
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Field Strength ◽  
Shock Front ◽  
Magnetic Field Strength ◽  
Plasma Flow ◽  
One Dimensional ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field ◽  
Steady Shock

An investigation was made of a steady, one-dimensional plasma flow in crossed electric and magnetic fields. The interaction between the flow and the fields causes various flow types. In general, the flow is either supersonic or subsonic in the entire channel. Under certain circumstances, however, a transsonic flow may develop. Finally, flows exist with a steady shock front, the position and strength of which depend on the magnetic field strength and the pressure at the end of the tube.

Analysis of the He i chromosphere in relation to the magnetic field activity over solar cycle time periods

2020 ◽  
Vol 497 (1) ◽  
pp. 969-975
Author(s):  
K J Li ◽  
W Feng
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Active Regions ◽  
Solar Observatory ◽  
Small Scale ◽  
Large Magnetic Field ◽  
National Solar Observatory ◽  
Magnetic Elements ◽  
The Magnetic Field

ABSTRACT Solar synoptic maps of both He i 10 830 Å intensity and the magnetic field, which are observed by the Vacuum Telescope at National Solar Observatory/Kitt Peak from 2005 July to 2013 March are utilized to study relationship of He i intensity of the weakly magnetized chromosphere with the respective magnetic field strength. Strong absorption in He i intensity presents the butterfly-pattern latitude migration zone as active regions do, indicating that strong magnetic field corresponds to high-temperature structures of the active chromosphere. For He i intensity and magnetic field strength, their distribution at the time-latitude coordinate and their time series at each of the 180 measurement latitude are found to be significantly negatively correlated with each other in most cases. When a solar hemisphere is divided into three latitude bands: low, middle, and high latitude bands, and even after large magnetic field values not taken into account, they are still negatively correlated in most cases, and further when large magnetic field values are subtracted He i intensity varies more sensitively with magnetic field strength than the corresponding cases when large magnetic field values are not subtracted. He i intensity in the quiet chromosphere thus mainly presents a negative correlation with the magnetic field, and the heating of the quiet chromosphere is inferred to be caused mainly by small-scale magnetic elements.

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.

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

2018 ◽  
Vol 615 ◽  
pp. A35 ◽  
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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