Brightness Temperature of Radio Zebras and Wave Energy Densities in Their Sources

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F17%3A00482456" target="_blank" >RIV/67985815:_____/17:00482456 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14310/17:00098163

Výsledek na webu

<a href="http://dx.doi.org/10.1007/s11207-017-1174-4" target="_blank" >http://dx.doi.org/10.1007/s11207-017-1174-4</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s11207-017-1174-4" target="_blank" >10.1007/s11207-017-1174-4</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Brightness Temperature of Radio Zebras and Wave Energy Densities in Their Sources

Popis výsledku v původním jazyce

We estimated the brightness temperature of radio zebras (zebra pattern - ZP), considering that ZPs are generated in loops having an exponential density profile in their cross section. We took into account that when in a plasma there is a source emitting in all directions, then in the escape process from the plasma the emission has a directional character nearly perpendicular to the constant-density profile. Owing to the high directivity of the plasma emission (for emission at frequencies close to the plasma frequency), the region from which the emission escapes can be very small. We estimated the brightness temperature of three observed ZPs for two values of the density scale height (1 and 0.21 Mm) and two values of the loop width (1 and 2 arcsec). In all cases, high brightness temperatures were obtained. For the higher value of the density scale height, the brightness temperature was estimated to be 1.1 x 10(15) -1.3 x 10(17) K, and for the lower value, it was 4.7 x 10(13) - 5.6 x 10(15) K. These temperatures show that the observational probability of a burst with a ZP, which is generated in the transition region with a steep gradient of the plasma density, is significantly higher than for a burst generated in a region with smoother changes of the plasma density.

Název v anglickém jazyce

Brightness Temperature of Radio Zebras and Wave Energy Densities in Their Sources

Popis výsledku anglicky

We estimated the brightness temperature of radio zebras (zebra pattern - ZP), considering that ZPs are generated in loops having an exponential density profile in their cross section. We took into account that when in a plasma there is a source emitting in all directions, then in the escape process from the plasma the emission has a directional character nearly perpendicular to the constant-density profile. Owing to the high directivity of the plasma emission (for emission at frequencies close to the plasma frequency), the region from which the emission escapes can be very small. We estimated the brightness temperature of three observed ZPs for two values of the density scale height (1 and 0.21 Mm) and two values of the loop width (1 and 2 arcsec). In all cases, high brightness temperatures were obtained. For the higher value of the density scale height, the brightness temperature was estimated to be 1.1 x 10(15) -1.3 x 10(17) K, and for the lower value, it was 4.7 x 10(13) - 5.6 x 10(15) K. These temperatures show that the observational probability of a burst with a ZP, which is generated in the transition region with a steep gradient of the plasma density, is significantly higher than for a burst generated in a region with smoother changes of the plasma density.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Solar Physics

ISSN

0038-0938

e-ISSN

—

Svazek periodika

292

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

"163/1"-"163/12"

Kód UT WoS článku

000413851500001

EID výsledku v databázi Scopus

2-s2.0-85032365353