Observation at radio frequencies of the hydroxyl (OH) absorption line in filaments and prominences above active regions of the Sun

Nina Ovchinnikova; V. Bogod; Mikhail Lebedev

doi:doi:10.12737/szf-103202403

UDC 52

Observation at radio frequencies of the hydroxyl (OH) absorption line in filaments and prominences above active regions of the Sun

Published в Solnechno-Zemnaya Fizika · Volume 10, Issue 3, 2024 · Pages 21–26 · Rubrics: 19TH ANNUAL CONFERENCE “PLASMA PHYSICS IN THE SOLAR SYSTEM”. FEBRUARY 5–9, 2024, SPACE RESEARCH INSTITUTE RAS, MOSCOW, RUSSIA

DOI 10.12737/szf-103202403

Received: 31.03.2024 Accepted: 23.05.2024 Published: 29.09.2024

Authors

Nina Ovchinnikova ¹ · V. Bogod ² · Mikhail Lebedev ³

1 Special Astrophysical Observatory
St. Petersburg, Russian Federation

2 St. Petersburg Branch of the Special Astrophysical Observatory of the Russian Academy of Sciences
Russian Federation

3 Special Astrophysical Observatory
St. Petersburg, Russian Federation

ABSTRACT

When observing the Sun with RATAN-600 radio telescope using a spectropolarimetric complex in the range 1–3 GHz, as well as when observing coronal rain, absorption in the radio emission was discovered in the spectral region 1.5–1.65 GHz in active solar regions located under a cold filament or on the limb under a prominence. The observed line structure corresponds to the hyperfine splitting frequencies in the ground state of X²Π₃/₂ hydroxyl (OH) 1612–1720 MHz. When the observed active region passes through the knife-shaped beam pattern of the telescope antenna, the absorption band shifts in frequency due to a shift in the energy levels of the OH molecule in a magnetic field, which changes along the filament.

KEYWORDS

Sun coronal structures absorption lines hydroxyl

Information Text

Authors:

1. Special Astrophysical Observatory

St. Petersburg, Russian Federation

2. St. Petersburg Branch of the Special Astrophysical Observatory of the Russian Academy of Sciences

Russian Federation

3. Special Astrophysical Observatory

St. Petersburg, Russian Federation

Type:

Article

Pages:

from 21 to 26

Status:

Published

Subject area:

UDC 52

Language:

Russian

Keywords:

Sun, coronal structures, absorption lines, hydroxyl

Funding

Observations by SAO RAS telescopes are supported by the Ministry of Science and Higher Education of the Russian Federation. Renovation of telescope equipment is currently provided within the national project "Science and Universities”

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Observation at radio frequencies of the hydroxyl (OH) absorption line in filaments and prominences above active regions of the Sun

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