HOP 0325

abstract of observational proposal

Main Objective:
Perform XRT cross calibration with the MinXSS cubesat spectra and use EIS spectra to create full sun DEM map for comparison to MinXSS measurements.

Scientific Justification:
The first Miniature X-ray Solar Spectrometer (MinXSS) cubesat was deployed on May 16, 2016, has been in normal science operations mode since June 10, 2016 and is providing spectrally resolved soft X-ray measurements. Simultaneous observations with Hinode XRT filters will be used to cross-calibrate the two instruments. Combined MinXSS and Hinode XRT data will be used to explore short term active region evolution (days -> weeks), long term solar x-ray variability (month -> years), give insight on the potential presence of hotter, (T > 6 MK) dimmer (EM < 1027 cm-5) plasma in active regions and chemical abundance variations.

These proposed XRT measurements will help constrain the relationship between the MinXSS spectra and XRT filter images and will serve as the baseline for future solar X-ray studies. EIS's capability of spectrally and semi-spatially resolved EUV measurements to create full sun raster mosaic images are essential for full sun DEMs estimates. These EIS UV derived DEMs can be used to synthesize the solar emission at other wavelengths like X-rays.

Finally, the EIS 40" slot full sun raster mosaic data at ~0.1 nm resolution will provide unique images of relatively well isolated spectral lines. These spectral line images allow for direct assessment of the coronal structure at different temperatures, elements and ionization states. These EIS mosaic and XRT images will be used in analyzing the validity of different coronal heating mechanisms in numerical simulations.

Coordinated XRT and MinXSS measurements will supply a wealth of data to address numerous questions about the physics and current conditions of the corona.

In summary our objectives are:

1. Cross-calibrate XRT with the MinXSS cubesat.
2. Construct EIS UV derived DEMs for comparison to MinXSS X-ray observations.
3. Perform a short term active region (or quiet sun if no ARs present) evolution study via x-rays.
4. Use EIS spectral line mosaic and XRT images to test the validity of coronal heating models in numerical simulations.

request to XRT

We desire full sun (synoptic), sun centered images taking by XRT during step #1, #3, are to be taken as stated in the DATES section We request the following filters below, in order to perform cross calibrations between the MinXSS cubesat and XRT.

- Al filters give estimations of spectral contributions mostly between 0.7 - 1.6 keV.
*Medium_Al*(short, medium and long exposures to increase dynamic range)
*Thick_Al*(*short if needed*, medium and long exposures to increase dynamic range)
- Medium_Be is critical!!, ~28 μm thickness of the Berylium window with the Si detector. This give a similar photon energy response to the MinXSS x-ray spectrometer response. Thus this is a critical filter for MinXSS - XRT cross calibration.
*Thin_Be* (short, medium and long exposures to increase dynamic range)
*Medium_Be* (short, medium and long exposures to increase dynamic range)
Thick_Be (long exposure time for a signal check)
-The Al_poly and Al_mesh are used for context images of the structure of the cooler solar atmosphere, for comparisons to SDO-AIA and for filter ratios.
Al_Poly (short, medium and long exposures to increase dynamic range)
Al_Mesh (short, medium and long exposures to increase dynamic range)
Dark - (3 exposures)
Bin all full sun images 2x2.
* = critical for MinXSS analysis please take these first if a priority must be set due to observation restrictions

request to EIS

For details see HOP 130. A summary is below.
EIS study acronym: FULL_SUN_SLOT_SCAN_2
TARGET: Full Sun (multiple pointings)
EXPOSURE TIME: 20s
RASTER: Scanning
SLIT: 40"
FOV: 488"x512"
DATA COMP: JPEG85
DURATION: ~4h (5.75 min/exposure + pointing stabilization+SAA avoidance, 26 exposures)
DATA VOLUME: 364MB (14MBits/exposure, 26 exposures)
SPECTRAL WIND.: 13
LINES: He II 256.3, Si VII 275.3, Fe VIII 185.2, Fe XI 180.4, Si X 258.42, S X 264.2, Fe XII 195.1, Fe XIII 202.0, Fe XIII 203.8, Fe XIV 211.36, Fe XIV 274.24, Fe XV 284.1, Fe XVI 262.9

Pointing
- 15 spacecraft pointings covering full disk. Two EIS pointings per spacecraft pointing: top and bottom of CCD in order to maximize area and minimize spacecraft pointings.

- This is a complex observation so for full details please check PDF file (hop_130_vX.X.pdf) at SolarSoft directory: $SSW/hinode/eis/idl/atest/ugarte
Email Ignacio Ugarte Urra at ignacio.ugarte-urra.ctr.sp@nrl.navy.mil with any specific questions.

remarks

Dates:
We desire two sets of XRT observations on two subsequent days and one set of EIS observations, on a specified day and a time most appropriate for Hinode set via communication between the Proposal P.I. and the Hinode Team.

Desired measurement order:
Measurements on the agreed upon start date (first available opening in the Hinode Observation Plan and when MinXSS is in a "good state)". These measurements are:

1. Two sets (groups of exposure types, e.i. *short* + medium + long) of synoptic full sun XRT images with each filter (with the filters and exposure types stated in the XRT section) before the EIS full sun raster, on Day 1 of the observation set.

2. EIS full sun raster as stated in HOP 130 (duration ~ 4 hours). To occur approximately as soon as reasonable possible after the XRT images in step 1.

3. Repeat of #1, two sets (groups of exposure types, e.i. short + medium + long) of Synoptic full sun XRT images with each filter (with the filters and exposure types stated in the XRT section) after the EIS full sun raster (#2), on the next UT day (Day 2).

4. *If possible a repeat to steps #1 - #3 starting somewhere between 4 – 6 days after “Day 2” from step #3 (for a solar temporal study)*

Time window:
Exact start time is what is most appropriate for the Hinode schedule on Day 1. What is important is that the sequence is maintained. If a precise start time is required, when the Hinode Observing Team provides a calendar date for the observation, the Proposal P.I. can give the time frames on that day, when MinXSS will be observing the Sun (sun side of orbit).
Short interruptions are OK for ten minute synoptic observations for all the observations stated in the previous section. It is desired that the transition from #1 to #2 and the observation therein are uninterrupted. Details are in the previous section.

For questions on the XRT requests please email Christopher Moore at Christopher.moore-1 at colorado.edu.

For questions on the EIS request, please email Ignacio Ugarte-Urra at ignacio.ugarteurra.ctr.sp@nrl.navy.mil.

Target(s) of interest:
XRT OBSERVATIONS: Full sun images at sun center. No other targets of interest.
EIS OBSERVATIONS: See HOP 130

Previous HOP information:
I have submitted HOP 0301 before.

Additional Remarks:
For XRT requests: Email Christopher Moore at Christopher.moore-1 at colorado.edu

For EIS requests:
Pointing
－ 15 spacecraft pointings covering full disk. Two EIS pointings per spacecraft pointing: top and
bottom of CCD in order to maximize area and minimize spacecraft pointings.
－ This is a complex observation so for full details please check PDF file (hop_130_vX.X.pdf) at
SolarSoft directory: $SSW/hinode/eis/idl/atest/ugarte
Email Ignacio Ugarte-Urra at ignacio.ugarte-urra.ctr.sp@nrl.navy.mil with any specific questions.
Duration:
－ ~16min at each pointing.
－ ~4h total with no gaps.
Frequency: approx. every 2-3 weeks to monitor activity.
SAA-free period preferred to minimize duration and facilitate planning. Other periods are OK.