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Title: HINODE OBSERVATION OF THE MAGNETIC FIELDS IN A SUNSPOT LIGHT BRIDGE ACCOMPANIED BY LONG-LASTING CHROMOSPHERIC PLASMA EJECTIONS

Abstract

We present high-resolution magnetic field measurements of a sunspot light bridge (LB) that produced chromospheric plasma ejections intermittently and recurrently for more than 1 day. The observations were carried out with the Hinode Solar Optical Telescope on 2007 April 29 and 30. The spectro-polarimeter reveals obliquely oriented magnetic fields with vertical electric current density higher than 100 mA m{sup -2} along the LB. The observations suggest that current-carrying highly twisted magnetic flux tubes are trapped below a cusp-shaped magnetic structure along the LB. The presence of trapped current-carrying flux tubes is essential for causing long-lasting chromospheric plasma ejections at the interface with pre-existing vertically oriented umbral fields. A bidirectional jet was clearly detected, suggesting magnetic reconnections occurring at very low altitudes, slightly above the height where the vector magnetic fields are measured. Moreover, we found another strong vertical electric current on the interface between the current-carrying flux tube and pre-existing umbral field, which might be a direct detection of the currents flowing in the current sheet formed at the magnetic reconnection sites.

Authors:
 [1]; ; ;  [2]; ;  [3]; ;  [4];
  1. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan)
  2. National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan)
  3. High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)
  4. Kwasan and Hida Observatories, Kyoto University, Kamitakara-cho, Takayama, Gifu 506-1314 (Japan)
Publication Date:
OSTI Identifier:
21300732
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal (Online)
Additional Journal Information:
Journal Volume: 696; Journal Issue: 1; Other Information: DOI: 10.1088/0004-637X/696/1/L66; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1538-4357
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; CHROMOSPHERE; MAGNETIC FIELDS; MAGNETIC FLUX; MAGNETIC RECONNECTION; PHOTOSPHERE; SUN; SUNSPOTS; TELESCOPES

Citation Formats

Shimizu, Toshifumi, Katsukawa, Yukio, Suematsu, Yoshinori, Tsuneta, Saku, Kubo, Masahito, Lites, Bruce W, Ichimoto, Kiyoshi, Nagata, Shin'ichi, Shine, Richard A, and Tarbell, Theodore D. HINODE OBSERVATION OF THE MAGNETIC FIELDS IN A SUNSPOT LIGHT BRIDGE ACCOMPANIED BY LONG-LASTING CHROMOSPHERIC PLASMA EJECTIONS. United States: N. p., 2009. Web. doi:10.1088/0004-637X/696/1/L66; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Shimizu, Toshifumi, Katsukawa, Yukio, Suematsu, Yoshinori, Tsuneta, Saku, Kubo, Masahito, Lites, Bruce W, Ichimoto, Kiyoshi, Nagata, Shin'ichi, Shine, Richard A, & Tarbell, Theodore D. HINODE OBSERVATION OF THE MAGNETIC FIELDS IN A SUNSPOT LIGHT BRIDGE ACCOMPANIED BY LONG-LASTING CHROMOSPHERIC PLASMA EJECTIONS. United States. https://doi.org/10.1088/0004-637X/696/1/L66; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)
Shimizu, Toshifumi, Katsukawa, Yukio, Suematsu, Yoshinori, Tsuneta, Saku, Kubo, Masahito, Lites, Bruce W, Ichimoto, Kiyoshi, Nagata, Shin'ichi, Shine, Richard A, and Tarbell, Theodore D. 2009. "HINODE OBSERVATION OF THE MAGNETIC FIELDS IN A SUNSPOT LIGHT BRIDGE ACCOMPANIED BY LONG-LASTING CHROMOSPHERIC PLASMA EJECTIONS". United States. https://doi.org/10.1088/0004-637X/696/1/L66; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
@article{osti_21300732,
title = {HINODE OBSERVATION OF THE MAGNETIC FIELDS IN A SUNSPOT LIGHT BRIDGE ACCOMPANIED BY LONG-LASTING CHROMOSPHERIC PLASMA EJECTIONS},
author = {Shimizu, Toshifumi and Katsukawa, Yukio and Suematsu, Yoshinori and Tsuneta, Saku and Kubo, Masahito and Lites, Bruce W and Ichimoto, Kiyoshi and Nagata, Shin'ichi and Shine, Richard A and Tarbell, Theodore D.},
abstractNote = {We present high-resolution magnetic field measurements of a sunspot light bridge (LB) that produced chromospheric plasma ejections intermittently and recurrently for more than 1 day. The observations were carried out with the Hinode Solar Optical Telescope on 2007 April 29 and 30. The spectro-polarimeter reveals obliquely oriented magnetic fields with vertical electric current density higher than 100 mA m{sup -2} along the LB. The observations suggest that current-carrying highly twisted magnetic flux tubes are trapped below a cusp-shaped magnetic structure along the LB. The presence of trapped current-carrying flux tubes is essential for causing long-lasting chromospheric plasma ejections at the interface with pre-existing vertically oriented umbral fields. A bidirectional jet was clearly detected, suggesting magnetic reconnections occurring at very low altitudes, slightly above the height where the vector magnetic fields are measured. Moreover, we found another strong vertical electric current on the interface between the current-carrying flux tube and pre-existing umbral field, which might be a direct detection of the currents flowing in the current sheet formed at the magnetic reconnection sites.},
doi = {10.1088/0004-637X/696/1/L66; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)},
url = {https://www.osti.gov/biblio/21300732}, journal = {Astrophysical Journal (Online)},
issn = {1538-4357},
number = 1,
volume = 696,
place = {United States},
year = {Fri May 01 00:00:00 EDT 2009},
month = {Fri May 01 00:00:00 EDT 2009}
}