THE RELATIONSHIP BETWEEN VERTICAL AND HORIZONTAL MAGNETIC FIELDS IN THE QUIET SUN

Journal Article · Sun Jul 10 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/735/2/74· OSTI ID:21578411

Ishikawa, Ryohko ^[1]; Tsuneta, Saku ^[2]

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1. Department of Astronomy, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)
2. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

Vertical magnetic fields have been known for decades to exist in the internetwork region of the Sun, while the properties of horizontal magnetic fields have only recently been extensively investigated with Hinode. Vertical and horizontal magnetic fields in the internetwork region are considered to be separate entities and have thus far not been investigated in a unified way. We discover a clear positional association between the vertical and horizontal magnetic fields in the internetwork region with Hinode. Essentially, all of the horizontal magnetic patches are associated with the vertical magnetic patches. Alternatively, half of the vertical magnetic patches accommodate the horizontal magnetic patches. These horizontal patches are located around the borders of the vertical patches. The intrinsic magnetic field strength as obtained with the Stokes V line ratio inside the horizontal patches is weak, and is in the subequipartition field regime (B < 700 G), while the field strength outside the horizontal patches ranges from weak to strong (kG) fields. Vertical magnetic patches are known to be concentrated on mesogranular and supergranular boundaries, while the horizontal magnetic patches are found only on mesogranular boundaries. These observations provide us with new information on the origin of the vertical and horizontal internetwork magnetic fields, in a unified way. We conjecture that internetwork magnetic fields are formed by the emergence of small-scale flux tubes with bipolar footpoints, and the vertical magnetic fields of the footpoints are intensified to kG fields due to convective collapse. Resultant strong vertical fields are advected by the supergranular flow, and eventually form the network fields.

• OSTI ID: 21578411
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 735; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ATMOSPHERES
CONVECTION
ENERGY TRANSFER
HEAT TRANSFER
MAGNETIC FIELDS
MAIN SEQUENCE STARS
MASS TRANSFER
PHOTOSPHERE
SOLAR ATMOSPHERE
STARS
STELLAR ATMOSPHERES
SUN