E-Print Archive

There are 3950 abstracts currently viewable.


Search:

Advanced Search
Options
Main Page Add New E-Print Submitter
Information
Feedback
News Help/FAQ About Preferences
Manage Key Phrase
Notification
HIGH-RESOLUTION OBSERVATIONS OF DOWNFLOWS AT ONE END OF A PRE-ERUPTION FILAMENT  

Qin Li   Submitted: 2017-05-31 19:22

Studying the dynamics of filaments at pre-eruption phase can shed light on the precursor of eruptive events. Such studies in high-resolution (in the order of 0.1") are highly desirable yet very rare so far. In this work, we present a detailed observation of a pre-eruption evolution of a filament obtained by the 1.6 m New Solar Telescope (NST) at Big Bear Solar Observatory (BBSO). One end of the filament is anchored at the sunspot in NOAA active region (AR) 11515, which is well observed by NST Hα off-bands four hours before till one hour after the filament eruption. A M1.6 flare is associated with the eruption. We observed persistent downflowing materials along the Hα multi-threaded component of the loop towards the AR end during the pre-eruption phase. We traced the trajectories of plasma blobs along the Hα threads and obtained the plane-of-sky velocity of 45 km s-1 on average. We further estimated the real velocities of the downflows and the altitude of the filament by matching the observed Hα threads with magnetic field lines extrapolated from a nonlinear force-free field (NLFFF) model. Observation of chromospheric brightenings (BZs) at the footpoints of the falling plasma blobs is also presented in the paper. The lower limit of the kinetic energy per second of the downflows through the BZs is found to be ~ 1021 erg. Larger FOV observations from BBSO full disk Hα images show that the AR end of the filament started ascending four hours before the flare. We attribute the observed downflows at the AR end of the filament to the draining effect of the filament rising prior to its eruption. During the slow-rise phase, the downflows continuously drained away ~ 1015g mass from the filament over a few hours, which is believed to be essential for the instability at last, and could be an important precursor of eruptive events.

Authors: Qin Li, Na Deng, Ju Jing, Haimin Wang
Projects: BBSO/NST

Publication Status: Published in The Astrophysical Journal, Volume 841, Number 2
Last Modified: 2017-06-01 10:21
Go to main E-Print page  Edit Entry  Download Preprint  Delete Entry 


Key
Go to main E-Print pageGo to main E-Print page.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
Delete AbstractDelete abstract.

Abstracts by Author
HIGH-RESOLUTION OBSERVATIONS OF DOWNFLOWS AT ONE END OF A PRE-ERUPTION FILAMENT

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey



© 2003 Solar Physics Group - Montana State University