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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0265

Searching for Non-Maxwellian Distributions with Comp-S

plan term


@ @


 name : Dudik, Dzifcakova, Williams, Del Zanna, Mason, Rybak @  e-mail : jd584[at]damtp.cam.ac.uk, elena[at]asu.cas.cz, d.r.williams[at]ucl.ac.uk, gd232[at]damtp.cam.ac.uk, hm11[at]damtp.cam.ac.uk, choc[at]astro.sk

contact person in HINODE team

 name : Williams @  e-mail : d.r.williams[at]ucl.ac.uk

 abstract of observational proposal
The assumption of the Maxwellian distribution is common in the analysis of astrophysical spectra. However, this assumption may be incorrect if the emitting plasma is heated dynamically e.g. by nanoflares. A possible signature of such dynamic heating in the solar corona would be the presence of non-Maxwellian distributions.

The -distributions, characterized by a high-energy tail, have been diagnosed in Si III SUMER spectra of the transition region (Dzifcakova & Kulinova 2011) and are also commonly observed in the solar wind (e.g. Maksimovic et al. 1997, Zouganelis 2008). Such distributions should result in an increase of the intensity of the coronal forbidden lines compared to the EUV ones (Dudík et al. 2014, A&A, submitted), an effect detectable by coordinated EIS and CoMP-S ground-based coronagraphic observations. This is the focus of this proposal.

However, to disentangle the effect of -distributions from the effects of the electron density and DEM, observations of additional EUV lines are needed for density and DEM diagnostics.

We propose this HOP to acquire unique joint observations by Hinode and CoMP‑S. As the target will be a limb active region, this will be a Target-of-Opportunity (ToO) HOP. The proposers will examine data from SDO and STEREO-A to determine, ahead of an observing plan, whether the observations should go ahead, and at which position angle on the limb. Given this point in the solar cycle, however, we expect that there will be a limb active region for much of the period.

If bad observing conditions are forecast at Lomnicky Peak, the observers there will inform the Hinode Chief Observers at least a day in advance that observations will not be required, in case there is time for Hinode to schedule other observations instead.

 request to SOT
No specific observations are requested due to the off-limb nature of these observations. We are happy to discuss what may be performed with the SOT team, however.

 request to XRT
Due to the long-duration nature of the EIS exposures, it would be helpful to have observations from XRT on a cadence matching the EIS exposures, and a duration matching the EIS observations, primarily for alignment purposes. The cadence of XRT should therefore be between 30 and 120 seconds, in one or more filters.

 request to EIS
CompS_NonMax has 4 different variations: 120, 90, 60 and 30 (number indicates the slit exposures in seconds). Use the CompS_NonMax study specified by proposer. All variations use 2" slit to scan an 80"x512" off-limb region in 2" steps. We have opted to use DPCM compression.

Observations should be run in the following sequence:
1. CompS_NonMax_30, CompS_NonMax_60, CompS_NonMax_90, or CompS_NonMax_120
2. PRY_slot_context_v3 (slot context)

Typically, the sequence should be repeated 3 times.

Pointing and study variation to be selected by J. Dudik (jd584@damtp.cam.ac.uk)

Typically, raster off-limb above AR core so that the innermost edge of the raster is 30" above the solar limb.

The target AR *must* be above the limb, otherwise CoMP-S will not be able to observe it.

Depending on the size of the AR, the proposer may specify that several rasters are to be stitched together to cover a wider range in X, in which case, this will be indicated in the instructions.

Observations should be performed during 08 UT-12 UT.  

Repeating the observations for as many consecutive days as possible is required to maximize the chance of best observing conditions. September and October offer the best "coronagraphic" conditions – sunny weather with good seeing – with a chance of 1:7). Therefore, we request three weeks of observing time from 9th October, to maximise our chances of good conditions at CoMP-S.

Once the target selection has been communicated to the Hinode COs, and the Hinode pointing plan has been finalized, please send target specifications (position angle and heliocentric co-ordinates) to CoMP-S observers before 05:00 UT on the observing day: ls_observer@astro.sk, rybak@astro.sk

 other participating instruments
Request to CoMP-S:
Use the largest FOV available, centered on an off-limb active region (coordinates should be supplied by the EIS Chief Observer to the Comp-S team).

Observations in the Fe X 6378 A and Fe XIV 5303 A lines are required with 18 points per profile, together with neighbouring "continuum" in order to separate the line intensity from the K corona.
Include the Fe XI 7897 A line or Fe XIII IR doublet if available.

SDO/AIA will offer context images for co-registration and additional information about the Fe XVIII upper limit (AIA 94A filter) for DEM modeling.

CompS_NonMax_[exptime] - Line list to be observed with EIS

(Wavelengths and counts according to Del Zanna (2012, A&A 537, A38),
Off-limb AR spectrum of 2007 Aug 19, 90s exposure.)

ion lambda th lambda obs [A]wvl window DN / 90s (*) Notes
Fe IX 188.497 188.490 188.13 - 188.82 490.6 kappa from EIS
Fe IX 189.941 189.931 189.58 - 190.27 277.7
Fe IX 194.784 194.817 194.41 - 195.46 170.7 kappa from EIS [in the Fe XII 195.12 window]
Fe IX 197.862 197.857 197.51 - 198.20 491.7 kappa from EIS

Fe X 184.537 184.538 184.18 - 184.87 825.7 kappa with CoMP-S
Fe X 190.037 190.040 189.53 - 190.76 1144.1 bl Fe XII
Fe X 193.715 193.710 193.34 - 194.03 508.2 kappa with CoMP-S
Fe X 257.262 257.264 256.88 - 258.10 614.2 T-sensitive

Fe XI 180.401 180.403 180.03 - 180.73 1006.4 bl Fe X, ne-diag
Fe XI 182.167 182.169 181.82 - 182.51 286.7 ne-diag
Fe XI 188.216 188.217 187.82 - 188.86 4860.7 bl oc, ne-diag
Fe XI 188.299 188.300 187.82 - 188.86 3048.1 bl u
Fe XI 190.382 190.382 189.53 - 190.76 372.8 sbl, bl u kappa
Fe XI 257.554 257.548 256.88 - 258.10 205.1 sbl, T, kappa
Fe XI 257.772 257.771 256.88 - 258.10 112.2 sbl, T, kappa

Fe XII 186.887 186.988 186.63 - 187.33 208.5 sbl, ne-diag
Fe XII 192.394 192.394 192.03 - 192.72 6068.7
Fe XII 195.119 195.118 194.41 - 195.46 23503.1 sbl

Fe XIII 196.525 196.530 196.17 - 196.86 703.8 ne-diag
Fe XIII 202.044 202.047 201.68 - 202.37 6915.7 ne-diag
Fe XIII 203.826 203.825 203.30 - 204.35 1124.4 bl Fe XII bw, ne-diag [extend towards blue wing - bl Fe XII]

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