!!!Joint Science Discussions with XRT and SOT.
__19th March 09:00__

''This page refers to one day of a closed [meeting of the EIS consortium|TeamMeetingMar09]''

[{TableOfContents }]
\\

!!Comments from attendees welcome!
__If you are attending this day of the meeting, please comment here if you would like to give input.__

Those without an EISWiki account (shame on you... if you're on the team!) can mail their comments and intended contribution topics to David Williams.

__It would be good to have a discussion about this agenda before the meeting, here on the EISWiki.__
!!Format
At this meeting, there will be additional attendance by invitees from XRT and SOT.



!!Objective
''What did we discover were thorny science questions in the EIS Science session?''
\\

The main point of this day session is to construct some observing programmes to conquer(!?) these questions using information from the EIS, SOT and XRT participants at this meeting.

!!!SOT & XRT Primers
Most people attending this session will be familiar with the kind of physics that the post-launch EIS offers information on. So we thought it would be useful to have a primer on each of the other two instruments’ scientific capabilities, with the benefit of 2.5 years of experience.

!!XRT (Kelly Korreck)
!XRT
XRT do ''have'' quasi-standard 
Flare mode is operational the
Automatic region selection: can read the patrol images which are interleaved.

Takes about a day to create a new programme. QL images are available within a day. Would want people to check those images
L0 data takes about a week to be

PRY: do the QL images go on the web?
KK: Not sure, but don't think so. Maybe they could.

* Data availability
5 sites available to find the L0 data.
can also use XRT_CAT (analogous to TRACE_CAT). Or ask an XRT Team member to be a co-author and 

KPD: is there an explanation of XRT_CAT
KK: XAG.pdf is in SSW and on the SAO webpage. Also have a file from the Paris workshop to show how

HEM: is it updated a lot?
KK: XRT_PREP is, but the analysis process isn't much different.
HEM: but the analysis guide
KK: There is someone tasked with providing the new version of the filter ratio programmes.

READ_XRT creates SSW-style index-data pairs. Then run {{XRT_PREP}} on that. There's been a lot of work on that.
Documentation is in the IDL software headers.

* Temperature analysis
At least 6 different filters needed to do DEM analysis with multi-filter sets.
No software ''yet'' to make movies.

JI: is there a synoptic daily temperature map?
KK: Not yet. Maybe Narukage has the way to do that.

* Co-alignment
This is still an open issue. 
HEM: How accurate is the header information.

* Effects on-orbit
** From Dec 2006 to Jan 2007, don't trust the header information: it's ''all'' Al_Poly.
** absorption layer is decreasing response ({{make_xrt_wave_resp}}). This is a time-dependent absorption function. So it's a fairly sticky bit of correction. There was a hope of coming up with a photometric correction. There's nothing in the software 
** spot-like contamination -- can remove this with {{xrt_tup_comtam}}. This does a simple averaging. Another to be released soon does gradient fits iteratively. The attenuation isn't 100%, though, so you can recover the contrast in those areas in many cases, with AR signal levels.
** cross-calibration with EIS, etc. May be a bone of contention?
** Co-alignment
** ...

TWo lists can be joined:
xrt_science -- discussion of science
xrt_users -- for end-users to provide support for one another.

KPD: one of the things I'd like to have are movies or time-sequences from a single filter or single exposure times. Can you make them with {{XRT_CAT}}?
KK: There's no standard
EDL: XRT_CAT, WHERE on filter wheel. 

*XBPs
''missed this part due to editor's prerogative''

*Sheared field in ARs through morphology.

*DEM intro:
Need 6 or 7 different filters to do this. Reeves broke the DEM up into images into different temperatures.
Can EIS be used to check some of this data. Helen and Kathy might wish to work onthis. Could we somehow make a filter respons for EIS.

*Flare shrinking loops through morphology

*Sigmoid structures
some people didn't know how big the EIS slit was and in general people didn't know what to ask for for morphology studies. ''maybe that cadence isn't the primary factor, then -- work on informing people about spatial coverage in a given time frame''.

* Polar jets: XRT are interested in getting densities out of them.

* CMEs See dimmings in XRT. If EIS were pointed at the same place.

*outflows: SO much easier to find in EIS than in XRT. Great use of EIS.

*Sheared loops within filament channels.

*Coronal waves

-- What have we learned to do to improve observations. Every time we want to look at the high-T plasma, we should have a programme where we know what XRT, EIS and SOT are doing.




!!SOT (Tom Berger)

!SOT Instrument
*BFI Characteristics ''is a great slide -- it explained a lot of the physics SOT was intended for.''

*NFI 
Na I D shows very little difference from the Fe I magnetograms
6300 Å now has a degraded blocking filter that means it can't be used. Shame, because it's used by the SP.

*SP

Spatial resolution shows magnetic elements with res down to 150 km. Not as good as some ground-based, but SOT gets this continually, rather than once or twice a year.

Spatial stability is good to about 0.01 arcsec RMS. CT works at around 840 Hz!

Focus stabiilty of the telescope -- telescope is continually shrinking so focus is changing but hasn't yet stabilised.

Focus stability during eclipse season isn't very good: you have a sort of 10-step shift. If you need absolute highest resolution, do it outside eclipse season.

EDL: Do you use a thicker slit in eclipse season?
TB: No - same slit.

You're not completely out of focus and can't see granulation, but you can still see the magnetic elements.

There is chromatic aberration - when you want to request NFI and SP, say which is your *primary* one.
The things I'm saying about resolution are non-summed. But if you sum on the camera, 2x2, then the defocus is much less important. Especially in the Ca II, this is quite common.

BFI Filter throughput decrease:
The loss isn't that great and can just increase the exposure time.

SOT NFI is down to 40 or so percent for Fe I 6302.5, but Na I D magnetograms at 589 are unaffected due to the other coating.

Current situation is that there is NO bubble in the NFI. And so we can now tune the filter back and forth!!
* 8 seconds or so to tune between lines. THe maximum cadence is about 8 seconds between 
ZnS coating on the H-alpha blocking filter means that it isn't routinely used, unless there's a special reason: AR, off-limb, key filament observations for a few hours.

Karin: I used to see fringes
TB: Yeah, but now the flat-fields take it out.

September-October and February-March are when the orbital Doppler shifts are minimal, so optimal for Dopplergram velocity.

EVen from relatively wimpish flux emergence in SOT, you can see very bright points in the corona with XRT.

Shine or Berger can do cork-maps to do LCT on granules and get a horizontal velocity field.

SST with the same analaysis... with a 1m telescope, you can get a mich higher resolution with much more regularity.

Ca II H at the limb: 1.6 second cadence. We believe we are now capturing the dynamics in spicules! Including what appear to be rotational motions.

They have standard data products for off-limb prominences
H-alpha dopplergrams, too.

Full SP takes about 3 hours in most sensitive 'normal' mode. Doesn't have the resolution of the FG: about a factor 2 worse.
FG suffers from Zeeman saturation when the spectral line moves out of the passband of the FG. But in the SP, this doesn't happen and you do get accurate data.

In L2 total polarisation maps, you can sometimes see very weak, fuzzy emission which indicates horizontal field emerging! Very sensitive.

Lites: No crosstalk between I,Q,U & V -- this is the BEST calibrated polarisation instrument known.

Planning: new calendar on Google: 

hinode.chiefobs@gmail.com calendar is editable by some people. PWD hatsuhinode lets you see it. Different HOPs have different colours. There are also calendars for instrument events. Have scheduled in the meetings.

Give it a try!

KPD: do you have any problems with pointing or keeping on a target in eclipse season? It doesn't look like it.
TB: It's enough so that if you were to try to overlay a raw SOT images onto an XRT image, it would be offset.
Shimizu-san has made a database online which allows correction of that to about 5 arcsec.
KPD: so outside eclipse season we should be able to do this quite well
DHB: there is a drift between SOT and EIS: what is that?
TB: That's the correlation tracker at work, and getting all the information together to work that out is challenging.
EDL: Do the data exist to complement the cork studies?
TB: would be good to ask Shine if he wants to go up higher into the atmosphere.

Karin: You can take out the slit motions in Y but how about in X?
TB: Actually this is only happening after the slit, on the Littrow, so it can't change the X position of the slit.




!!!Addressing Our Major Science Goals
''Discussion Session''
Having talked about
1. the science issues we think are outstanding for EIS, (previous day)
2. what SOT and XRT can offer in terms of physical observations,
we need to marry these and work out what co-observations we all want in order to address our major science goals.


!!Invitees
*SOT:
**Tom Berger
***Additional input from Bruce Lites ''(not attending)''
**Jack Ireland
**Ted Tarbell
**Alex Young

*XRT:
**Ed DeLuca
**Kelly Korreck

!!Topics
These will be an output from the previous day's [EIS Team Science Meeting|TeamSciMeetingMar09].
\\
%%collapsebox
!!Attendees
*Khalid al-Janabi (MSSL)
*Danielle Bewsher (RAL)
*David Brooks (NRL)
*Charlie Brown (NRL)
*Paul Bryans (NRL)
*Len Culhane (MSSL)
*Ken Dere (GMU)
*George Doschek (US PI; NRL)
*Alessandro Gardini (UiO)
*Hirohisa Hara (NAOJ)
*Louise Harra (PI; MSSL)
*Shinsuke Imada (NAOJ)
*John Mariska (NRL)
*Helen Mason (DAMTP)
*Keiichi Matsuzaki (ISAS)
*Ryan Milligan (GSFC)
*Karin Muglach (NRL)
*Steve Myers (NRL)
*John Rainnie (RAL)
*Toshifumi Shimizu (ISAS)
*Ignacio Ugarte Urra (NRL)
*Harry Warren (NRL)
*Tetsuya Watanabe (Japan PI; NAOJ)
*[David Williams|DavidRWilliams] (MSSL)
*Peter Young (NRL)
%%
\\


\\