TY - JOUR
T1 - GONG Catalog of Solar Filament Oscillations Near Solar Maximum
AU - Luna, M.
AU - Karpen, J.
AU - Ballester, J. L.
AU - Muglach, K.
AU - Terradas, J.
AU - Kucera, T.
AU - Gilbert, H.
N1 - Publisher Copyright:
© 2018. The American Astronomical Society.
PY - 2018/6
Y1 - 2018/6
N2 - We have cataloged 196 filament oscillations from the Global Oscillation Network Group Hα network data during several months near the maximum of solar cycle 24 (2014 January-June). Selected examples from the catalog are described in detail, along with our statistical analyses of all events. Oscillations were classified according to their velocity amplitude: 106 small-amplitude oscillations (SAOs), with velocities >10 km s-1, and 90 large-amplitude oscillations (LAOs), with velocities <10 km s-1. Both SAOs and LAOs are common, with one event of each class every two days on the visible side of the Sun. For nearly half of the events, we identified their apparent trigger. The period distribution has a mean value of 58±15 minutes for both types of oscillations. The distribution of the damping time per period peaks at τ/P=1.75 and 1.25 for SAOs and LAOs, respectively. We confirmed that LAO damping rates depend nonlinearly on the oscillation velocity. The angle between the direction of motion and the filament spine has a distribution centered at 27° for all filament types. This angle agrees with the observed direction of filament-channel magnetic fields, indicating that most of the cataloged events are longitudinal (i.e., undergo field-aligned motions). We applied seismology to determine the average radius of curvature in the magnetic dips, R ≈ 89 Mm, and the average minimum magnetic field strength, B ≈ 16 G. The catalog is available to the community online and is intended to be expanded to cover at least 1 solar cycle.
AB - We have cataloged 196 filament oscillations from the Global Oscillation Network Group Hα network data during several months near the maximum of solar cycle 24 (2014 January-June). Selected examples from the catalog are described in detail, along with our statistical analyses of all events. Oscillations were classified according to their velocity amplitude: 106 small-amplitude oscillations (SAOs), with velocities >10 km s-1, and 90 large-amplitude oscillations (LAOs), with velocities <10 km s-1. Both SAOs and LAOs are common, with one event of each class every two days on the visible side of the Sun. For nearly half of the events, we identified their apparent trigger. The period distribution has a mean value of 58±15 minutes for both types of oscillations. The distribution of the damping time per period peaks at τ/P=1.75 and 1.25 for SAOs and LAOs, respectively. We confirmed that LAO damping rates depend nonlinearly on the oscillation velocity. The angle between the direction of motion and the filament spine has a distribution centered at 27° for all filament types. This angle agrees with the observed direction of filament-channel magnetic fields, indicating that most of the cataloged events are longitudinal (i.e., undergo field-aligned motions). We applied seismology to determine the average radius of curvature in the magnetic dips, R ≈ 89 Mm, and the average minimum magnetic field strength, B ≈ 16 G. The catalog is available to the community online and is intended to be expanded to cover at least 1 solar cycle.
KW - Sun: filaments, prominences
KW - Sun: magnetic fields
KW - Sun: oscillations
KW - catalogs
UR - https://www.scopus.com/pages/publications/85049187716
U2 - 10.3847/1538-4365/aabde7
DO - 10.3847/1538-4365/aabde7
M3 - Article
AN - SCOPUS:85049187716
SN - 0067-0049
VL - 236
JO - Astrophysical Journal, Supplement Series
JF - Astrophysical Journal, Supplement Series
IS - 2
M1 - 35
ER -