<div dir="ltr"><br><div>This looks very nice. Can you rule out any heating mechanisms? Is the </div><div>really hot stuff (in)consistent with the emergence and dissipation of new magnetic field from below via a long-lived reconnection due to the underlying continuous emergence of flux?</div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jul 27, 2017 at 3:18 AM, Susanna Parenti <span dir="ltr"><<a href="mailto:susanna.parenti@ias.u-psud.fr" target="_blank">susanna.parenti@ias.u-psud.fr</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<font face="Times New Roman, Times, serif">Dear all,<br>
<br>
here is a new paper just accepted for publication on the ApJ. It
provides evidence for very hot plasma above the limb observed for
an AR using spectroscopic observations from Fe X to Fe XIX. We
quantify the spatial and temporal properties of this plasma. Main
results: the hot plasma is detected in various places above the
limb which are at different heights; its thermal properties are
not changing much over the duration of the observations (17h) . <br>
<br>
Regards,<br>
<br>
Susanna Parenti<br>
<br>
<br>
</font>
<pre><a class="m_-8991697206052037496moz-txt-link-freetext" href="http://arxiv.org/abs/1707.08445" target="_blank">http://arxiv.org/abs/1707.<wbr>08445</a>
<font face="Times New Roman, Times, serif">
</font></pre>
<font face="Times New Roman, Times, serif">Spectroscopy of very hot
plasma in non-flaring parts of a solar limb active region: spatial
and temporal properties.</font><br>
<br>
<font face="Times New Roman, Times, serif">In this work we
investigate the thermal structure of an off-limb active
region in various non-flaring areas, as it provides key
information on the way
these structures are heated. In particular, we concentrate in the
very hot
component (>3 MK) as it is a crucial element to discriminate
between different
heating mechanisms. We present an analysis using Fe and Ca
emission lines from
both SOHO/SUMER and HINODE/EIS. A dataset covering all ionization
stages from
Fe X to Fe XIX has been used for the thermal analysis (both DEM
and EM). Ca XIV
is used for the SUMER-EIS radiometric cross-calibration. We show
how the very hot plasma is present and persistent almost
everywhere
in the core of the limb AR. The off-limb AR is clearly structured
in Fe XVIII.
Almost everywhere, the EM analysis reveals plasma at 10 MK
(visible in Fe XIX
emission) which is down to 0.1% of EM of the main 3 MK plasma. We
estimate the
power law index of the hot tail of the EM to be between -8.5 and
-4.4. However,
we leave an open question on the possible existence of a small
minor peak at
around 10 MK. The absence in some part of the AR of Fe XIX and Fe
XXIII lines
(which fall into our spectral range) enables us to determine an
upper limit on
the EM at such temperatures. Our results include a new Ca XIV
943.59 \AA~
atomic model</font><br>
<br>
<br>
<br>
<font face="Times New Roman, Times, serif"> </font>
</div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div><div><div><div><div><div><div><div><div><div><font face="arial,helvetica,sans-serif">Philip Judge </font><span style="font-family:arial,helvetica,sans-serif;font-size:19.2px">303-775-9863</span></div></div></div></div></div></div></div></div></div></div></blockquote><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div><div><div><div><div><div><div><div><div><font face="arial,helvetica,sans-serif">Senior Scientist, </font><span style="font-family:arial,helvetica,sans-serif;font-size:19.2px">HAO, NCAR </span></div></div></div></div></div></div></div></div></div></blockquote><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div><div><div><div><div><div><div><div><div><span style="font-family:arial,helvetica,sans-serif;font-size:19.2px">Editor-in Chief, Open Astronomy</span></div></div></div></div></div></div></div></div></div></blockquote><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div><div><div><div><div><div><div><div><div><span style="font-size:19.2px;font-family:arial,helvetica,sans-serif"><br></span></div></div></div></div></div></div></div></div></div></blockquote><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div><div><div><div><div><div><div><div><div><a href="https://www.degruyter.com/view/j/astro" style="font-size:19.2px;font-family:arial,helvetica,sans-serif" target="_blank">https://www.degruyter.com/view/j/astro</a></div></div></div></div></div></div></div></div></div></blockquote><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div><div><div><div><div><div><div><div><div><p><a href="http://people.hao.ucar.edu/judge/homepage/" style="font-size:19.2px" target="_blank">http://people.hao.ucar.edu/judge/homepage/</a></p></div></div></div></div></div></div></div></div></div></blockquote></blockquote><blockquote style="margin:0 0 0 40px;border:none;padding:0px"><div><div dir="ltr"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><p><br></p></div></div></div></div></div></div></div></div></div></blockquote><div><div dir="ltr"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><p><br></p></div></div></div></div></div></div></div></div></div></div></div>
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