Filigree in the Surroundings of Polar Crown and High-Latitude Filaments
arXiv:2012.04349 · doi:10.1007/s11207-021-01776-7
Abstract
High-resolution observations of polar crown and high-latitude filaments are scarce. We present a unique sample of such filaments observed in high-resolution H narrow-band filtergrams and broad-band images, which were obtained with a new fast camera system at the Vacuum Tower Telescope (VTT), Tenerife, Spain. The Chromospheric Telescope (ChroTel) provided full-disk context observations in H, Ca II K, and He I 10830 A. The Helioseismic and Magnetic Imager (HMI) and the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) provided line-of-sight magnetograms and ultraviolet (UV) 1700 A filtergrams, respectively. We study filigree in the vicinity of polar crown and high-latitude filaments and relate their locations to magnetic concentrations at the filaments' footpoints. Bright points are a well studied phenomenon in the photosphere at low latitudes, but they were not yet studied in the quiet network close to the poles. We examine size, area, and eccentricity of bright points and find that their morphology is very similar to their counterparts at lower latitudes, but their sizes and areas are larger. Bright points at the footpoints of polar crown filaments are preferentially located at stronger magnetic flux concentrations, which are related to bright regions at the border of supergranules as observed in UV filtergrams. Examining the evolution of bright points on three consecutive days reveals that their amount increases while the filament decays, which indicates they impact the equilibrium of the cool plasma contained in filaments.
arXiv comment26 pages, 11 figures, 1 table, accepted for publication in Solar Physics
References in corpus (30)
- Physics of Solar Prominences: II - Magnetic Structure and Dynamics
- Solar fine-scale structures. I. Spicules and other small-scale, jet-like events at the chromospheric level: observations and physical parameters
- An active region filament studied simultaneously in the chromosphere and photosphere: I - Magnetic structure
- Bright points in the inter-network quiet Sun
- Velocity vectors of a quiescent prominence observed by Hinode/SOT and the MSDP (Meudon)
- Magnetic properties of G-band bright points in a sunspot moat
- On the Magnetic Field Strength of Active Region Filaments
- The Area Distribution of Solar Magnetic Bright Points
- The GREGOR Fabry-Pérot Interferometer
- The Chromospheric Telescope
- Horizontal flow fields observed in Hinode G-band images. I. Methods
- Real-time flare detection in ground-based H imaging at Kanzelhöhe Observatory
- Magnetic field strength distribution of magnetic bright points inferred from filtergrams and spectro-polarimetric data
- The formation and disintegration of magnetic bright points observed by Sunrise/IMaX
- Vector magnetic fields of Solar Granulation
- Recent advancements in the EST project
- Counter-streaming flows in a giant quiet-Sun filament observed in the extreme ultraviolet
- A giant quiescent solar filament observed with high-resolution spectroscopy
- Latitude migration of solar filaments
- Horizontal flow fields observed in Hinode G-band images IV. Statistical properties of the dynamical environment around pores
- Height variation of magnetic field and plasma flows in isolated bright points
- Collective Study of Polar Crown Filaments in the Past Four Solar Cycles
- On the structure and evolution of a polar crown prominence/filament system
- sTools - a data reduction pipeline for the GREGOR Fabry-Pérot Interferometer and the High-resolution Fast Imager at the GREGOR solar telescope
- Chromospheric Synoptic Maps of Polar Crown Filaments
- Occurrence and persistence of magnetic elements in the quiet Sun
- Subarcsecond Bright Points and Quasi-periodic Upflows Below a Quiescent Filament Observed by the IRIS
- Calibration of full-disk He I 10830 Å filtergrams of the Chromospheric Telescope
- The polarization signature of photospheric magnetic fields in 3D MHD simulations and observations at disk center
- High-resolution spectroscopy of an erupting minifilament and its impact on the nearby chromosphere