Dear all,
Happy, healthy and productive 2014!
We recently got published a couple of papers on coronal loops that might interest you:
Hot coronal loops associated with umbral brightenings, Alissandrakis, C. E.; Patsourakos, S. http://adsabs.harvard.edu/abs/2013A%26A...556A..79A
Core and Wing Densities of Asymmetric Coronal Spectral Profiles: Implications for the Mass Supply of the Solar Corona Patsourakos, S.; Klimchuk, J. A.; Young, P. R. http://adsabs.harvard.edu/abs/2014ApJ...781...58P
Best wishes
Spiros Patsourakos
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Spiros Patsourakos Assistant Professor University of Ioannina Dept Physics-Section Astrogeophysics GR 451 10 Ioannina Greece
Phone: +30 2 651 00 8478 Fax: +30 2 651 00 8699 Email: spatsour@cc.uoi.gr
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Dear all,
I'd like to draw your attention to a paper recently published in A&A that may be of interest to you.
http://www.aanda.org/articles/aa/abs/2014/03/aa22572-13/aa22572-13.html http://arxiv.org/abs/1312.3792
It describes slow (periods of several hours) pulsations discovered in coronal loops. We present a few typical events plus a statistical analysis of the main properties of the hundreds of events detected during solar cycle 23. They went mostly unnoticed up to now (probably because their detection requires the systematic analysis of a large quantity of data), but they seem to be common in coronal loops. The cause for these pulsations is still unclear, but they are likely related to the way the loops are heated.
We'd be happy to discuss any suggestion you may have regarding the physical nature of these new phenomena.
Share & enjoy,
Frédéric Auchère
Dear Frédéric,
A very interesting stuff indeed. I’d also like to attract your attention to the paper "Leakage of long-period oscillations from the chromosphere to the corona” by Yuan et al., A&A 533, id.A116, 2011, http://adsabs.harvard.edu/abs/2011A%26A...533A.116Y were we presented the detection of long-period (about one hour) oscillations in the corona.
All the best,
Valery
On 3 Mar 2014, at 13:54, Frédéric Auchère frederic.auchere@ias.u-psud.fr wrote:
Dear all,
I'd like to draw your attention to a paper recently published in A&A that may be of interest to you.
http://www.aanda.org/articles/aa/abs/2014/03/aa22572-13/aa22572-13.html http://arxiv.org/abs/1312.3792
It describes slow (periods of several hours) pulsations discovered in coronal loops. We present a few typical events plus a statistical analysis of the main properties of the hundreds of events detected during solar cycle 23. They went mostly unnoticed up to now (probably because their detection requires the systematic analysis of a large quantity of data), but they seem to be common in coronal loops. The cause for these pulsations is still unclear, but they are likely related to the way the loops are heated.
We'd be happy to discuss any suggestion you may have regarding the physical nature of these new phenomena.
Share & enjoy,
Frédéric Auchère
Loops mailing list Loops@solar.physics.montana.edu https://mithra.physics.montana.edu/mailman/listinfo/loops
Thanks for the info Valery, I missed that paper.
Le 03/03/2014 15:58, Nakariakov, Valery a écrit :
Dear Frédéric,
A very interesting stuff indeed. I’d also like to attract your attention to the paper "Leakage of long-period oscillations from the chromosphere to the corona” by Yuan et al., A&A 533, id.A116, 2011, http://adsabs.harvard.edu/abs/2011A%26A...533A.116Y were we presented the detection of long-period (about one hour) oscillations in the corona.
All the best,
Valery
On 3 Mar 2014, at 13:54, Frédéric Auchère frederic.auchere@ias.u-psud.fr wrote:
Dear all,
I'd like to draw your attention to a paper recently published in A&A that may be of interest to you.
http://www.aanda.org/articles/aa/abs/2014/03/aa22572-13/aa22572-13.html http://arxiv.org/abs/1312.3792
It describes slow (periods of several hours) pulsations discovered in coronal loops. We present a few typical events plus a statistical analysis of the main properties of the hundreds of events detected during solar cycle 23. They went mostly unnoticed up to now (probably because their detection requires the systematic analysis of a large quantity of data), but they seem to be common in coronal loops. The cause for these pulsations is still unclear, but they are likely related to the way the loops are heated.
We'd be happy to discuss any suggestion you may have regarding the physical nature of these new phenomena.
Share & enjoy,
Frédéric Auchère
Loops mailing list Loops@solar.physics.montana.edu https://mithra.physics.montana.edu/mailman/listinfo/loops
Loops mailing list Loops@solar.physics.montana.edu https://mithra.physics.montana.edu/mailman/listinfo/loops
Dear all,
Abundance measurements in Active Region Cores
Interestingly, a re-analysis of the good old SMM/FCS observations of quiescent active region cores, using up-to-date atomic data, confirms earlier results based on Hinode/EIS (Del Zanna 2013, A&A, 555, A47).
The Fe/Ne and Fe/O ratios are remarkably similar for different ARs, with an FIP bias of about 3, the same as was found in terms of Fe/Ar and Fe/S for a few ARs from Hinode EIS (Del Zanna 2013,A&A, 558, A73). These abundances are different from previous results by other authors, but apply only to the hot (about 3 MK) AR core loops.
In terms of emission above 3 MK, the SMM/FCS results are also in agreement with previous results from Hinode EIS, with a sudden drop in the emission measure for higher temperatures, and very little Fe XVIII emission.
The MAGIXS instrument would provide an excellent opportunity to combine simultaneous EUV and X-ray spectroscopy of ARs, and to study further these diagnostics.
The A&A paper is available at http://adsabs.harvard.edu/abs/2014A%26A...565A..14D and a preprint at http://solar.physics.montana.edu/cgi-bin/eprint/index.pl?entry=23180
Giulio and Helen
Dear all,
Simultaneous observations with Hinode EIS and XRT. O'Dwyer, Del Zanna and Mason
We have carried out a detailed comparison between simultaneous Hinode EIS and XRT observations for a solar flare, active region and quiet Sun region. Good agreement is found using the recent new radiometric calibration for EIS (Del Zanna, 2013,A&A, 555,A47). We discuss the various contributions to the XRT bands from different spectral lines and the continuum. In addition, we assess the importance of the elemental abundances when deriving DEMs from the XRT bands.
The A&A paper is available at http://adsabs.harvard.edu/abs/2014A%26A...561A..20O and a preprint at http://solar.physics.montana.edu/cgi-bin/eprint/index.pl?entry=23181
cheers Giulio & Helen
loops@solar.physics.montana.edu