A new view of quiet-Sun topology from Hinode/SOT

Regnier, Stephane, Parnell, Clare and Haynes, Andrew (2008) A new view of quiet-Sun topology from Hinode/SOT. Astronomy & Astrophysics, 484 (3). L47-L50. ISSN 0004-6361

regnier_aa_2008a.pdf - Published Version

Download (581kB) | Preview
Official URL: http://dx.doi.org/10.1051/0004-6361:200809826


Context. With the recent launch of the Hinode satellite our view of the nature and evolution of quiet-Sun regions has been improved. In light of the new high resolution observations, we revisit the study of the quiet Sun's topological nature.
Aims. Topology is a tool to explain the complexity of the magnetic field, the occurrence of reconnection processes, and the heating of the corona. This Letter aims to give new insights to these different topics.
Methods. Using a high-resolution Hinode/SOT observation of the line-of-sight magnetic field on the photosphere, we calculate the three dimensional magnetic field in the region above assuming a potential field. From the 3D field, we determine the existence of null points in the magnetic configuration.
Results. From this model of a continuous field, we find that the distribution of null points with height is significantly different from that reported in previous studies. In particular, the null points are mainly located above the bottom boundary layer in the photosphere (54%) and in the chromosphere (44%) with only a few null points in the corona (2%). The density of null points (expressed as the ratio of the number of null points to the number of photospheric magnetic fragments) in the solar atmosphere is estimated to be between 3% and 8% depending on the method used to identify the number of magnetic fragments in the observed photosphere.
Conclusions. This study reveals that the heating of the corona by magnetic reconnection at coronal null points is unlikely. Our findings do not rule out the heating of the corona at other topological features. We also report the topological complexity of the chromosphere as strongly suggested by recent observations from Hinode/SOT.

Item Type: Article
Uncontrolled Keywords: Sun: magnetic fields, Sun: photosphere, Sun: chromosphere, Sun: corona
Subjects: F500 Astronomy
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: Stephane Regnier
Date Deposited: 08 Jun 2015 07:58
Last Modified: 17 Dec 2023 16:36
URI: https://nrl.northumbria.ac.uk/id/eprint/21306

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics