Quiet sun brightness temperature in the millimeter-wavelength range

1982 ◽  
Vol 25 (9) ◽  
pp. 698-702
Author(s):  
S. A. Pelyushenko
Keyword(s):  
Brightness Temperature ◽  
Wavelength Range ◽  
Quiet Sun ◽  
Millimeter Wavelength

scholarly journals ELECTRODELESS MEASUREMENT TECHNIQUE OF COMPLEX DIELECTRIC PERMITTIVITY OF HIGH-K DIELECTRIC FILMS IN THE MILLIMETER WAVELENGTH RANGE

2016 ◽  
Vol 52 ◽  
pp. 161-167 ◽  
Author(s):  
Igor V. Kotelnikov ◽  
Andrey G. Altynnikov ◽  
Anatoly Konstantinovich Mikhailov ◽  
Valentina V. Medvedeva ◽  
Andrey Kozyrev
Keyword(s):  
Dielectric Permittivity ◽  
Wavelength Range ◽  
Measurement Technique ◽  
Complex Dielectric Permittivity ◽  
Dielectric Films ◽  
Millimeter Wavelength ◽  
High K ◽  
High K Dielectric

Investigation of coherent Vavilov-Cherenkov radiation in the millimeter wavelength range generated in PTFE and paraffin target

2011 ◽  
Vol 5 (2) ◽  
pp. 326-329 ◽  
Author(s):  
M. V. Shevelev ◽  
G. A. Naumenko ◽  
A. P. Potylitsyn ◽  
L. G. Sukhikh ◽  
Yu. A. Popov
Keyword(s):  
Wavelength Range ◽  
Cherenkov Radiation ◽  
Millimeter Wavelength

scholarly journals Modeling the quiet Sun cell and network emission with ALMA

2020 ◽  
Vol 640 ◽  
pp. A57 ◽  
Author(s):  
C. E. Alissandrakis ◽  
A. Nindos ◽  
T. S. Bastian ◽  
S. Patsourakos
Keyword(s):  
Electron Temperature ◽  
Brightness Temperature ◽  
Absolute Calibration ◽  
Solar Chromosphere ◽  
Temperature Structure ◽  
Cell Interior ◽  
Network Cell ◽  
Quiet Sun ◽  
Millimeter Wavelengths ◽  
Cell Segregation

Observations of the Sun at millimeter wavelengths with the Atacama Large Millimeter/submillimeter Array (ALMA) offer a unique opportunity to investigate the temperature structure of the solar chromosphere. In this article we expand our previous work on modeling the chromospheric temperature of the quiet Sun, by including measurements of the brightness temperature in the network and cell interiors, from high-resolution ALMA images at 3 mm (Band 3) and 1.26 mm (Band 6). We also examine the absolute calibration of ALMA full-disk images. We suggest that the brightness temperature at the center of the solar disk in Band 6 is ∼440 K above the value recommended by White et al. (2017, Sol. Phys., 292, 88). In addition, we give improved results for the electron temperature variation of the average quiet Sun with optical depth and the derived spectrum at the center of the disk. We found that the electron temperature in the network is considerably lower than predicted by model F of Fontenla et al. (1993, ApJ, 406, 319) and that of the cell interior considerably higher than predicted by model A. Depending on the network/cell segregation scheme, the electron temperature difference between network and cell at τ = 1 (100 GHz) ranges from ∼660 K to ∼1550 K, compared to ∼3280 K predicted by the models; similarly, the electron temperature, Te ratio ranges from ∼1.10 to 1.24, compared to ∼1.55 of the model prediction. We also found that the network/cell Te(τ) curves diverge as τ decreases, indicating an increase of contrast with height and possibly a steeper temperature rise in the network than in the cell interior.

Variation of Quiet Sun Radiation during Solar Cycles 23 and 24

2017 ◽  
Vol 13 (S335) ◽  
pp. 11-13
Author(s):  
Mahender Aroori ◽  
G. Yellaiah ◽  
K. Chenna Reddy
Keyword(s):  
Radio Emission ◽  
Brightness Temperature ◽  
Statistical Method ◽  
Solar Radio ◽  
Solar Radio Emission ◽  
Solar Cycles ◽  
Quiet Sun ◽  
Data Centre ◽  
National Geophysical Data ◽  
Using Data

AbstractRadio observations play a very important role in understanding the structure of the solar atmosphere. In this paper the quiet sun component of the solar radio emission has been investigated using data obtained from the Solar Indices Bulletin, National Geophysical Data Centre. By statistical method, the quiet sun component is estimated for 84 successive basic periods containing three solar rotations each using data obtained at different frequencies. From the quiet sun component we estimate the brightness temperature in each observing frequency.

High-Efficiency Relativistic Generators of Nanosecond Pulses in the Millimeter-Wavelength Range

2019 ◽  
Vol 62 (7-8) ◽  
pp. 467-471
Author(s):  
V. V. Rostov ◽  
R. V. Tsygankov ◽  
A. S. Stepchenko ◽  
O. B. Koval’chuk ◽  
K. A. Sharypov ◽  
...  
Keyword(s):  
Wavelength Range ◽  
High Efficiency ◽  
Millimeter Wavelength ◽  
Nanosecond Pulses

scholarly journals First high-resolution look at the quiet Sun with ALMA at 3mm

2018 ◽  
Vol 619 ◽  
pp. L6 ◽  
Author(s):  
A. Nindos ◽  
C. E. Alissandrakis ◽  
T. S. Bastian ◽  
S. Patsourakos ◽  
B. De Pontieu ◽  
...  
Keyword(s):  
High Resolution ◽  
Brightness Temperature ◽  
Disk Center ◽  
Image Resolution ◽  
Quiet Sun ◽  
Chromospheric Network ◽  
Local Background ◽  
First Time ◽  
Full Disk

We present an overview of high-resolution quiet Sun observations, from disk center to the limb, obtained with the Atacama Large millimeter and sub-millimeter Array (ALMA) at 3 mm. Seven quiet-Sun regions were observed at a resolution of up to 2.5″ by 4.5″. We produced both average and snapshot images by self-calibrating the ALMA visibilities and combining the interferometric images with full-disk solar images. The images show well the chromospheric network, which, based on the unique segregation method we used, is brighter than the average over the fields of view of the observed regions by ∼305 K while the intranetwork is less bright by ∼280 K, with a slight decrease of the network/intranetwork contrast toward the limb. At 3 mm the network is very similar to the 1600 Å images, with somewhat larger size. We detect, for the first time, spicular structures, rising up to 15″ above the limb with a width down to the image resolution and brightness temperature of ∼1800 K above the local background. No trace of spicules, either in emission or absorption, is found on the disk. Our results highlight the potential of ALMA for the study of the quiet chromosphere.

Consistent Determination of the Integral Humidity and Effective Optical Depth of the Atmosphere in the Millimeter Wavelength Range Using Wideband Radiometers

2020 ◽  
Vol 62 (12) ◽  
pp. 820-829
Author(s):  
G. M. Bubnov ◽  
V. F. Grigor’ev ◽  
I. I. Zinchenko ◽  
P. M. Zemlyanukha ◽  
G. N. Il’in ◽  
...  
Keyword(s):  
Optical Depth ◽  
Wavelength Range ◽  
Millimeter Wavelength
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