Hi everyone,
In the spirit of a number of recent papers that have been focused on trying
to determine the dominant components of the emission in the wavelength
channels of imaging instruments (AIA, in particular), Jim and I would like
to share with you all a link to a paper on this very topic that was recently
published in the ApJ Supplement Series:
http://iopscience.iop.org/0067-0049/194/2/26/pdf/apjs_194_2_26.pdf
Our aim in carrying out the work described in this paper was to provide a
large amount of quantitative data from our modeling studies that we hope
will be of use in the analysis of observationally gathered data.
Best wishes,
Steve
-----Original Message-----
From: loops-bounces(a)solar.physics.montana.edu
[mailto:loops-bounces@solar.physics.montana.edu] On Behalf Of Paola Testa
Sent: Tuesday, September 20, 2011 10:00 AM
To: A mailing list for scientists involved in the observation and modeling
of solar loop structures
Cc: Juan Martinez Sykora
Subject: [Loops] Forward modeling of emission in SDO/AIA passbands from
dynamic 3D simulations
Hello all,
here is a link to a preprint of a paper, accepted for publication on ApJ,
that is also discussing issues related to the interpretation of AIA
observations:
http://adsabs.harvard.edu/abs/2011arXiv1109.0704M
cheers,
Paola
On 9/9/11 12:03 PM, Giulio Del Zanna wrote:
>
> Dear colleagues,
>
> here is a link to a preprint that discusses various
> (important) issues related to the interpretation of AIA data:
>
> http://solar.physics.montana.edu/cgi-bin/eprint/index.pl?entry=15555
>
> Those of you that were present at the excellent Mallorca meeting might
> recall the issues we raised there. The paper, which follows on from
> O'Dwyer et al., contains more.
>
> I encourage all to follow the example in the Appendix to calculate
> your own AIA responses using CHIANTI. We will soon release v.7, but do
> not expect huge differences.
> We are working to try and improve the atomic data for AIA, more to come.
>
>
> best wishes,
_______________________________________________
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Loops(a)solar.physics.montana.edu
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Hi Loopsters,
We enjoyed a very successful workshop in Mallorca. Many thanks to the SOC and LOC and especially to their chairs, Inaki Ugarte Urra and Jose Luis Ballester, respectively. These guys put in a lot of hard work.
We also thank Spiro Antiochos, Joan Schmelz, and Robert Walsh, whose terms on the Steering Committee are ending. Please send me nominations for their replacements, including self nominations. The Steering Committee will then vote from a list of candidates. (Spiro, Joan, and Robert are eligible to serve again.)
It's never too early to start planning for the next workshop, in 2 years. Please contact me if you are interested in hosting. We have some tentative offers already, but they are highly tentative at this time.
Best wishes,
Jim
********************************************************************************
James A. Klimchuk
NASA Goddard Space Flight Center
Solar Physics Lab, Code 671
Bldg. 21, Rm. 158
Greenbelt, MD 20771
USA
Phone: 1-301-286-9060
Fax: 1-301-286-7194
E-mail: James.A.Klimchuk(a)nasa.gov<mailto:James.A.Klimchuk@nasa.gov>
Home page: http://science.gsfc.nasa.gov/671/staff/bios/cs/James_Klimchuk_ssi.html
No endorsement by NASA is implied for any correspondence related to my role as an officer of professional organizations (American Geophysical Union, American Astronomical Society, International Astronomical Union).
********************************************************************************
Dear colleagues
please find at the following link the preprint of a work accepted
for publication in Astronomy & Astrophysics, showing tests on the
capability of MCMC method to reconstruct isothermal DEMs:
http://arxiv.org/abs/1112.2857
The abstract is below.
Best regards
Fabio Reale
Monte Carlo Markov Chain DEM reconstruction of isothermal plasmas
E. Landi, F. Reale, P. Testa
In this paper, we carry out tests on the Monte Carlo Markov Chain (MCMC)
technique with the aim of determining: 1) its ability to retrieve
isothermal plasmas from a set of spectral line intensities, with and
without random noise; 2) to what extent can it discriminate between an
isothermal solution and a narrow multithermal distribution; and 3) how
well it can detect multiple isothermal components along the line of
sight. We also test the effects of 4) atomic data uncertainties on the
results, and 5) the number of ions whose lines are available for the DEM
reconstruction. We find that the MCMC technique is unable to retrieve
isothermal plasmas to better than Delta log T = 0.05. Also, the DEM
curves obtained using lines calculated with an isothermal plasma and
with a Gaussian distribution with FWHM of log T = 0.05 are very similar.
Two near-isothermal components can be resolved if their temperature
separation is Delta log T = 0.2 or larger. Thus, DEM diagnostics has an
intrinsic resolving power of log T = 0.05. Atomic data uncertainties may
significantly affect both temperature and peak DEM values, but do not
alter our conclusions. The availability of small sets of lines also does
not worsen the performance of the MCMC technique, provided these lines
are formed in a wide temperature range. Our analysis shows the present
limitations in our ability to identify the presence of strictly
isothermal plasmas in stellar and solar coronal spectra.