A Multi-Wavelength View of an Active Region Structure around a Filament Channel L. Lundquist,1 K. Reeves,1 A. van Ballegooijen,1 T. Sakao,2 and the XRT Team 1Harvard Smithsonian Center for Astrophysics 2Institute of Space and Astronautical Science,

1
A Multi-Wavelength View of an Active Region
Structure around a Filament Channel L.
Lundquist,1 K. Reeves,1 A. van Ballegooijen,1 T.
Sakao,2 and the XRT Team 1Harvard Smithsonian
Center for Astrophysics 2Institute of Space and
Astronautical Science, JAXA
The combination of multi-wavelength, high
resolution, high cadence data from the Hinode
X-Ray Telescope (XRT) and the Transition Region
And Coronal Explorer (TRACE) give a unique view
of solar active region dynamics and topology in
different wavelengths. We present results from
NOAA active region 10930, observed in December
2006, and active region 10940, observed in
February 2007. Co-alignment of XRT and TRACE data
yield a striking combination of a filament
structure observed in TRACE and hot XRT loops
that lie both above and along the filament
channel. In the December case, overlying loops
exhibit remarkable dynamics while the filament
lies dormant, and numerous x- point and
triple-leg structures undergo repeated
brightenings. We find that TRACE and XRT
observations are complementary, and correlation
of these data facilitates co-alignment with other
instruments.
Case 1 Active region 10930, Dec 14, 2006
Overlay of XRT and TRACE
Overlay of XRT and TRACE
XRT AL/poly 2-Feb-2007 1818
TRACE 195 2-Feb-2007 1819, with XRT contours
Co-alignment of XRT and TRACE data reveal
complementary structures and illuminate the
relationship between the filament channel and the
hot X-ray loops. Loops lying both along and above
the filament apparently result in the many
x-point reconnection events observed at the
intersection of these two types of loops.
XRT Thin-Be 2006-Dec-14 1057
Hot x-ray loops with cool moss footpoints arc
over the filament
TRACE 195 2006-Dec-14 1057
XRT contours overlaid on TRACE 195 data again
show moss structures at the base of hot loops.
Some X-ray structures appear to lie along the
filament
Tri-leg reconnection example
Tri-leg reconnection event
Before small flare
During this small flaring event, brightenings
along the filament channel are observed, followed
by this apparent reconnection of the
filament-overlying and filament-parallel
structures. Similar examples are repeated about
three times.
Flare and H-alpha context
Conclusions and Future Work
Kanzelhohe H-alpha
GOES X-ray flux
XRT and TRACE present complementary high- and
low-temperature views of the active region
corona. AR 10930 shows a fascinating example of
hot X-ray loops both along and above a filament
channel, which reconnect repeatedly in x-point
and tri-leg structures. The location and
orientation of the hot loops with respect to the
filament is made clear only through comparison
with TRACE. Aligning data from the two
instruments remains challenging, and in this
poster, it is still being done at the level of
manual feature comparison. In the case of the
December 2006 data, we were able to use the
footpoint moss structures and presence of a
filament channel to align the data sets by eye.
In the case of the February 2007 data set, the
primary alignment is still done by hand, but we
are aided by the additional information from
secondary data sets. MDI or SOLIS data, for
example, provide a full-sun image that can be
aligned by the limb to full-Sun XRT images. They
also provide white light data which can be
compared to TRACE white light data. Future work
will explore the efficacy of this approach. A
similar method will be applied to to Hinode
XRT-SOT co-alignment in the absence of G-band
observations from XRT.
The repeated small flares in most cases involves
reconnection of the structures lying along the
filament and those lying over it.