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Title: PENUMBRAL-LIKE FILAMENTS IN THE SOLAR PHOTOSPHERE AS A MANIFESTATION OF FLUX EMERGENCE

Rare observations of the solar photosphere show the appearance of orphan penumbrae, filamentary structures very similar to a bundle of sunspot penumbral filaments not connected to any umbra. Lim et al. found an orphan penumbra in active region NOAA 11391 near a mature sunspot. We analyze a different data set to study the same structure using the Solar Optical Telescope on board the Hinode satellite. Spectropolarimetric measurements along the Fe I 630.2 nm pair, complemented by G-band and Ca II H filtergrams, show the evolution of this penumbral-like structure and reveal that an emerging flux region is its ancestor. We find new evidence for the interaction between the emerging flux and the pre-existing field that leads to a brightening observed near the base of the chromosphere. Our analysis suggests that as a result of the combination of photospheric flux emergence and magneto-convection in inclined fields the horizontal component of the emerging field can be trapped in the photosphere by the overlying fields and form a structure resembling penumbral filaments.
Authors:
;  [1] ;  [2]
  1. Dipartimento di Fisica e Astronomia, Università di Catania, Via S. Sofia 78, I-95123 Catania (Italy)
  2. INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy)
Publication Date:
OSTI Identifier:
22365856
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 786; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CALCIUM IONS; CHROMOSPHERE; CONVECTION; FILAMENTS; IRON IONS; MAGNETIC FIELDS; PHOTOSPHERE; RESOLUTION; SATELLITES; SUN; SUNSPOTS; TELESCOPES; TRAPPING