J/ApJ/721/901 Solar quiescent filament channels (Su+, 2010)
Structure and dynamics of quiescent filament channels observed by Hinode/XRT
and STEREO/EUVI.
Su Y., van Ballegooijen A., Golub L.
<Astrophys. J., 721, 901-910 (2010)>
=2010ApJ...721..901S 2010ApJ...721..901S
ADC_Keywords: Sun ; X-ray sources ; Ultraviolet
Keywords: Sun: activity - Sun: corona - Sun: filaments, prominences -
Sun: magnetic topology - Sun: UV radiation - Sun: X-rays, gamma rays
Abstract:
We present a study of the structure and dynamics of quiescent filament
channels observed by Hinode/XRT and STEREO/EUVI at the solar minimum
23/24 from 2006 November to 2008 December. For 12 channels identified
on the solar disk (Group I channels), we find that the morphology of
the structure on the two sides of the channel is asymmetric in both
X-rays and EUV: the eastern side has curved features while the western
side has straight features. We interpret the results in terms of a
magnetic flux rope model. The asymmetry in the morphology is due to
the variation in axial flux of the flux rope along the channel, which
causes the field lines from one polarity to turn into the flux rope
(curved feature), while the field lines from the other polarity are
connected to very distant sources (straight). For most of the 68
channels identified by cavities at the east and west limbs (Group II
channels), the asymmetry cannot be clearly identified, which is likely
due to the fact that the axial flux may be relatively constant along
such channels. Corresponding cavities are identified only for 5 of the
12 Group I channels, while Group II channels are identified for all of
the 68 cavity pairs. The studied filament channels are often observed
as dark channels in X-rays and EUV. Sheared loops within Group I
channels are often seen in X-rays, but are rarely seen in Group II
channels as shown in the X-ray Telescope daily synoptic observations.
A survey of the dynamics of studied filament channels shows that
filament eruptions occur at an average rate of 1.4 filament eruptions
per channel per solar rotation.
Description:
Filament channels and cavities are selected from the synoptic
observations taken by X-ray Telescope (XRT) on board Hinode. The
underlying photospheric magnetic field information is provided by
SOLIS. Hα filament information is obtained from observations at
the Mauna Loa Solar Observatory (MLSO), Kanzelhohe Solar Observatory
(KSO), and Big Bear Solar Observatory (BBSO). Filament eruptions are
identified based on observations at HeII 304Å by STEREO/EUVI
(primarily) and XRT synoptic observations (occasionally). SOHO/LASCO
and STEREO/SECCHI provide us with CME information.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 87 68 Group II filament channels
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See also:
J/A+AS/130/233 : WATCH Solar X-Ray Burst Catalogue (Crosby+ 1998)
J/A+AS/110/99 : White-light flares models (Fang+, 1995)
J/A+A/304/563 : Cool X-ray flares of Sun with GOES (Phillips+, 1995)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Index number
4- 14 A11 "YYYY/MMM/DD" DateE ? Date of East limb cavity start date
16- 17 I2 d EXRT [1/14]? Days when East cavity is visible
in XRT
19- 29 A11 "YYYY/MMM/DD" DateW ? Date of West limb cavity start date
31- 32 I2 d WXRT [1/18]? Days when West cavity is visible
in XRT
34- 44 A11 "YYYY/MM/DD" Date Channel date
46- 51 A6 --- Hem/Lat Hemisphere and latitude
53 I1 --- S [1/4]? Channel structure
55- 72 A18 --- Erupt Filament eruption date (Month(s) and day(s))
74- 87 A14 --- CME Coronal mass ejection (CME) associated with
Filament eruption? (Yes or No for the
different eruption date(s))
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 09-Jul-2012