HOMOLOGOUS HELICAL JETS: OBSERVATIONS BY IRIS, SDO, AND HINODE AND MAGNETIC MODELING WITH DATA-DRIVEN SIMULATIONS

• Published in: The Astrophysical journal Vol. 801; no. 2; pp. 1 - 13
• Main Authors: Cheung, Mark C. M., Pontieu, B. De, Tarbell, T. D., Fu, Y., Tian, H., Testa, P., Reeves, K. K., Martínez-Sykora, J., Boerner, P., Wülser, J. P., Lemen, J., Title, A. M., Hurlburt, N., Kleint, L., Kankelborg, C., Jaeggli, S., Golub, L., McKillop, S., Saar, S., Carlsson, M., Hansteen, V.
• Format: Journal Article
• Language: English; Norwegian
• Published: United States The American Astronomical Society 10.03.2015; University of Chicago Press
• Subjects: ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CHROMOSPHERE; COMPARATIVE EVALUATIONS; Computer simulation; Doppler effect; EMISSION SPECTRA; FAR ULTRAVIOLET RADIATION; Helical; JETS; MAGNETIC FIELDS; PHOTOSPHERE; PLASMA; Porosity; Solar observatories; SPACE VEHICLES; SUN; Sun: atmosphere; Sun: chromosphere; Sun: corona; Sun: photosphere; Sun: transition region; TIME DEPENDENCE; TOPOLOGY; VELOCITY
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1088/0004-637X/801/2/83

ABSTRACT We report on observations of recurrent jets by instruments on board the Interface Region Imaging Spectrograph, Solar Dynamics Observatory (SDO), and Hinode spacecraft. Over a 4 hr period on 2013 July 21, recurrent coronal jets were observed to emanate from NOAA Active Region 11793. Far-ultraviolet spectra probing plasma at transition region temperatures show evidence of oppositely directed flows with components reaching Doppler velocities of 100 km s−1. Raster Doppler maps using a Si iv transition region line show all four jets to have helical motion of the same sense. Simultaneous observations of the region by SDO and Hinode show that the jets emanate from a source region comprising a pore embedded in the interior of a supergranule. The parasitic pore has opposite polarity flux compared to the surrounding network field. This leads to a spine-fan magnetic topology in the coronal field that is amenable to jet formation. Time-dependent data-driven simulations are used to investigate the underlying drivers for the jets. These numerical experiments show that the emergence of current-carrying magnetic field in the vicinity of the pore supplies the magnetic twist needed for recurrent helical jet formation.