Morphology of Solar Type II Bursts Caused by Shock Propagation through Turbulent and Inhomogeneous Coronal Plasma

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F23%3A00574430" target="_blank" >RIV/67985815:_____/23:00574430 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0345191" target="_blank" >https://hdl.handle.net/11104/0345191</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/acdbcc" target="_blank" >10.3847/1538-4357/acdbcc</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Morphology of Solar Type II Bursts Caused by Shock Propagation through Turbulent and Inhomogeneous Coronal Plasma

Popis výsledku v původním jazyce

Type II solar bursts are radio signatures of shock waves in the solar corona driven by solar flares or coronal mass ejections (CMEs). Therefore, these bursts present complex spectral morphologies in solar dynamic spectra. Here, we report meter-decameter radio observations of a type II burst on 2014 July 25 made with the Ukrainian radio telescopes UTR-2 (8.25-33 MHz) and GURT (8.25-78 MHz). The burst demonstrates fundamental and harmonic components, band splitting, a herringbone structure, and a spectral break. These specific spectral features, observed jointly in a single type II burst, are rarely detected. To contribute to our understanding of such puzzling type II events, we carried out a detailed analysis of the recorded type II dynamic spectrum. In particular, the herringbone pattern has been exploited to study electron density turbulence in the solar corona. We calculated the power spectral densities of the flux variations in selected herringbones. The spectral index is in the range of & alpha, =1.69 to2.00 with an average value of1.897, which is slightly higher than the Kolmogorov spectral index of5/3 for fully developed turbulence. We also recognized that the second type II burst consists of three drifting lanes. The lane onset times coincide with the spectral break in the first type II burst. We regard that the CME/shock passage through a streamer caused the spectral break and triggered the multilane type II radio emission. Thus, we support one of the proposed scenarios for type II burst occurrence as being the result of CME/shock-streamer interaction.

Název v anglickém jazyce

Morphology of Solar Type II Bursts Caused by Shock Propagation through Turbulent and Inhomogeneous Coronal Plasma

Popis výsledku anglicky

Type II solar bursts are radio signatures of shock waves in the solar corona driven by solar flares or coronal mass ejections (CMEs). Therefore, these bursts present complex spectral morphologies in solar dynamic spectra. Here, we report meter-decameter radio observations of a type II burst on 2014 July 25 made with the Ukrainian radio telescopes UTR-2 (8.25-33 MHz) and GURT (8.25-78 MHz). The burst demonstrates fundamental and harmonic components, band splitting, a herringbone structure, and a spectral break. These specific spectral features, observed jointly in a single type II burst, are rarely detected. To contribute to our understanding of such puzzling type II events, we carried out a detailed analysis of the recorded type II dynamic spectrum. In particular, the herringbone pattern has been exploited to study electron density turbulence in the solar corona. We calculated the power spectral densities of the flux variations in selected herringbones. The spectral index is in the range of & alpha, =1.69 to2.00 with an average value of1.897, which is slightly higher than the Kolmogorov spectral index of5/3 for fully developed turbulence. We also recognized that the second type II burst consists of three drifting lanes. The lane onset times coincide with the spectral break in the first type II burst. We regard that the CME/shock passage through a streamer caused the spectral break and triggered the multilane type II radio emission. Thus, we support one of the proposed scenarios for type II burst occurrence as being the result of CME/shock-streamer interaction.

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

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2023

Kód důvěrnosti údajů

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

Název periodika

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Svazek periodika

952

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

9

Strana od-do

51

Kód UT WoS článku

001030729000001

EID výsledku v databázi Scopus

2-s2.0-85165708682