Subarcsecond Imaging of a Solar Active Region Filament With ALMA and IRIS
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F22%3A00558171" target="_blank" >RIV/67985815:_____/22:00558171 - isvavai.cz</a>
Result on the web
<a href="http://hdl.handle.net/11104/0332248" target="_blank" >http://hdl.handle.net/11104/0332248</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.3389/fspas.2022.898115" target="_blank" >10.3389/fspas.2022.898115</a>
Alternative languages
Result language
angličtina
Original language name
Subarcsecond Imaging of a Solar Active Region Filament With ALMA and IRIS
Original language description
Quiescent filaments appear as absorption features on the solar disk when observed in chromospheric lines and at continuum wavelengths in the millimeter (mm) range. Active region (AR) filaments are their small-scale, low-altitude analogues, but they could not be resolved in previous mm observations. This spectral diagnostic can provide insight into the details of the formation and physical properties of their fine threads, which are still not fully understood. Here, we shed light on the thermal structure of an AR filament using high-resolution brightness temperature (T-b) maps taken with ALMA Band 6 complemented by simultaneous IRIS near-UV spectra, Hinode/SOT photospheric magnetograms, and SDO/AIA extreme-UV images. Some of the dark threads visible in the AIA 304 & ANGS - passband and in the core of Mg ii resonance lines have dark (T-b < 5,000 K) counterparts in the 1.25 mm maps, but their visibility significantly varies across the filament spine and in time. These opacity changes are possibly related to variations in temperature and electron density in filament fine structures. The coolest T-b values ( < 5,000 K) coincide with regions of low integrated intensity in the Mg ii h and k lines. ALMA Band 3 maps taken after the Band 6 ones do not clearly show the filament structure, contrary to the expectation that the contrast should increase at longer wavelengths based on previous observations of quiescent filaments. The ALMA maps are not consistent with isothermal conditions, but the temporal evolution of the filament may partly account for this.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10308 - Astronomy (including astrophysics,space science)
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2022
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Frontiers in Astronomy and Space Sciences
ISSN
2296-987X
e-ISSN
2296-987X
Volume of the periodical
9
Issue of the periodical within the volume
May
Country of publishing house
CH - SWITZERLAND
Number of pages
10
Pages from-to
898115
UT code for WoS article
000807328400001
EID of the result in the Scopus database
2-s2.0-85131863307