[Loops] More Hinode AR loops - Ugarte-Urra et al. 2009, ApJ

[Hugh Hudson]

Dear Ignacio et al.

I've always suspected that even the cores of active region had both  
kinds of loop population. This is based on what SXT saw, but also  
from the elementary fact that GOES light curves clearly have a flare- 
like and steady component that somehow compete. I don't think the  
steady part could come from peripheral loops below 1.3 MK.

That said, now I'll read the paper!

Hugh

On Jan 9, 2009, at 1:54 PM, Ignacio Ugarte Urra wrote:

> Hi all,
>
> Just wanted to let you know about a paper on EIS/XRT observations of
> coronal loops just accepted by ApJ.
>
> http://arxiv.org/abs/0901.1075
>
> Title: "Active region transition region loop populations and their
> relationship to the corona"
> Authors: Ignacio Ugarte-Urra, Harry P. Warren and David H. Brooks
>
> Abstract:
> The relationships among coronal loop structures at different
> temperatures is not settled. Previous studies have suggested that
> coronal loops in the core of an active region are not seen cooling
> through lower temperatures and therefore are steadily heated. If loops
> were cooling, the transition region would be an ideal temperature  
> regime
> to look for a signature of their evolution. The Extreme-ultraviolet
> Imaging Spectrometer (EIS) on Hinode provides monochromatic images of
> the solar transition region and corona at an unprecedented cadence and
> spatial resolution, making it an ideal instrument to shed light on  
> this
> issue. Analysis of observations of active region 10978 taken in 2007
> December 8 -- 19 indicates that there are two dominant loop  
> populations
> in the active region: core multi-temperature loops that undergo a
> continuous process of heating and cooling in the full observed
> temperature range 0.4-2.5 MK and even higher as shown by the X-Ray
> Telescope (XRT); and peripheral loops which evolve mostly in the
> temperature range 0.4-1.3 MK. Loops at transition region temperatures
> can reach heights of 150 Mm in the corona above the limb and develop
> downflows with velocities in the range of 39-105 km/s.
>
> Best,
> Ignacio
> -- 
> ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
>  ~ Ignacio Ugarte-Urra ~
>    Naval Research Laboratory. Code 7673U.
>    4555 Overlook Ave SW. Washington, DC 20375
>    Contractor. Spain.
>    phone: (+1) 202 404 1779
>    email: iugarte at ssd5.nrl.navy.mil
>    http:  http://tcrb.nrl.navy.mil/~iuu
> ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
>
> _______________________________________________
> Loops mailing list
> Loops at solar.physics.montana.edu
> https://mithra.physics.montana.edu/mailman/listinfo/loops

+++++++++++++++++++++

In medias res
hhudson at ssl.berkeley.edu
+1 (510) 643-0333

AST:7731^29u18e3



-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mithra.physics.montana.edu/pipermail/loops/attachments/20090109/8346ee68/attachment-0001.htm