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Model Instruments Baseline Specification and Key Open Issues – X-ray Imaging Telescope (XIT) –

Model Instruments Baseline Specification and Key Open Issues – X-ray Imaging Telescope (XIT) –. Taro Sakao (ISAS/JAXA). Imaging Observation of the Corona. TRACE 171Å. EIS 195Å. EIS 284Å. SXR (XRT). Phenomenological “connectivity” between the base of

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Model Instruments Baseline Specification and Key Open Issues – X-ray Imaging Telescope (XIT) –

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  1. Model Instruments Baseline Specification and Key Open Issues– X-ray Imaging Telescope (XIT) – Taro Sakao (ISAS/JAXA) Solar-C Meeting @ St Andrews

  2. Imaging Observation of the Corona TRACE 171Å EIS 195Å EIS 284Å SXR (XRT) Phenomenological “connectivity” between the base of the corona and the chromosphere/transition region with EUV-line images Heating and activities of hot loops with broad-band soft X-ray images “What corona do we want to see?” Solar-C Meeting @ St Andrews

  3. Introduction • X-ray Imaging (Spectroscopic) Telescope for Solar-C • Solar-C: Perform seamless observations of the solar atmosphere (photosphere, chromosphere, transition region and corona) with a suite of 3 telescopes. • Expected contributions from imaging observations of the corona • Reveal forms and mechanisms of (storage and) dissipation of energy • Quantitative understanding on the reconnection physics • Connectivity with the lower atmosphere • Two possibilities under study for the X-ray telescope • (1) Ultra-high-resolution normal incidence EUV telescope Context information for LEMUR • (2) Photon-counting imaging-spectroscopic grazing incidence X-ray telescope Solar-C Meeting @ St Andrews

  4. Current Concept of X/EUV Telescope for Solar-CA Pair of NI and GI Channels • Normal Incidence • Ultra-high-resolution with high-cadence imagery in EUV wavebands • Connectivity with lower atmosphere • Context information for LEMUR • 0.2-0.3” angular resolution (0.1”/pixel) with cadence <10 s for AR/FL • 171, 94 and 304 (or 1548 UV) Å bands • Grazing Incidence • Highest spatial-resolution soft X-ray imaging-spectroscopy • Provide physical context (entire loop info.) for NI observations with its wide temperature coverage • Photon-counting capability for reconnection structure etc. • ~< 1” angular resolution (0.4-0.5”/pixel) • 0.9o (~<2 keV) and 0.45o (~0.5-10 keV) grazing angles • Photon-counting with 0.45o Solar-C Meeting @ St Andrews

  5. Preliminary Illustration of Solar-C X/EUV Telescope“Everything in a package” 3 NI Channels: 94, 171, 304 Å (or 1548 Å) 2 GI Channels: 0.9 deg & 0.45 deg graz. angles * 0.45 deg  Photon Counting (Figure courtesy of SAO) Solar-C Meeting @ St Andrews

  6. Ultra-High-Resolution EUV Telescope Solar-C Meeting @ St Andrews

  7. Correspondence of low corona and chromosphere at ultra-fine scales AIA 193Å NST He I 10830-0.25Å Ji, Cao, and Goode 2012, ApJ - BBSO/NST He I 10830Å - SDO/AIA 171 Å Structure with diameter ~100 km Solar-C Meeting @ St Andrews

  8. Solar-C Meeting @ St Andrews

  9. Preliminary Features of Ultra-High-Resolution EUV Telescope • Image • Lower TR • Lower corona • Hot corona (with 1 MK) Provide context for EUVS/LEMUR Solar-C Meeting @ St Andrews

  10. NI Line Selection • Science with NI telescope(s) largely depends on which wavelength bands are to be employed. • In addition to 171 Å band:Will there be 304 Å (He II) band?  Yes (or UV-band?) • Imaging of spicules and prominences can be made at spatial resolution similar to SOT-FG. (Joint observation with SUVIT.) • Will there be science output beyond SOT-FG? • Temperature difference between 0.1 MK (lower TR with NI) and 0.02 MK (upper choromosphere with SOT) would be important? • Will there be wavelength bands with >5 MK contribution (94 Å and/or 335 Å) besides 1-2 MK bands? Yes, 94 Å • High-temperature bands would be useful in identifying heating sites. • The current baseline NI bands (171, 304, 94 Å) are more oriented to take narrow-temperature-band (“single-temperature”) images, overlapping with LEMUR temperatures.[171 (5.9), 304 (4.7), 94 (blend of 6.0 & 6.9 for flares)]

  11. Grazing-Incidence X-ray Telescope with Photon-Counting Capability Solar-C Meeting @ St Andrews

  12. Science Targets of the GI Telescope (Photon-Counting) • Energy dissipation processes in the corona that lead to dynamic activities of the corona. • MHD structures assoc. with magnetic reconnection during flares • Identify, e.g., shock structures (slow shock, fast shock) • Plasma conditions (temperature, heating status) in the upstream/downstream regions of a shock • Electron temperatures from continuum spectra • Spatial distribution and evolution of supra-thermal electrons(which serve as the seed for accelerated electrons) • Heating mechanism for active regions • In particular, for hot plasmas in the AR core: • Spatial and temporal evolution of spectra with high time resolution by virtue of non-dispersive imaging-spectroscopy* Particularly powerful under the nano-flare-heating picture for ARs. • Spatial distribution of spectral features (Disk AR・・lateral, Limb AR・・・vertical） Solar-C Meeting @ St Andrews

  13. Possibilities:Shocks in the Reconnection Structure Energy range covering up to ~10 keV should clearly identify presence of supra-thermal electron components e- distribution spectra outside diffusion region Supra-thermal electrons Thermal electrons 10 keV e- distribution spectra around reconnection point Imada et al. JGR 2011 (Tsuneta,Ap.J.1996) (Tsuneta,Ap.J.1996) Electron acceleration at Earth’s magnetotail Solar-C Meeting @ St Andrews (Tsuneta,Ap.J.1997)

  14. Expected Observation Target Regarding Reconnection Physics (Aschwanden et al. 1996) 1% of Peak EM 20% of Peak EM • Typ. Electron TOF distance • ~ 1.43 x Loop half-length • Not much far from SXR loop main body • May be able to perform proper • photon-counting imagery around • e- start point! (Tsuneta et al. 1997) Solar-C Meeting @ St Andrews

  15. Expected AR Count Spectra ~15 s Integration for 1.2”-square Area Red: with 10MK component Black: without 10MK compo. (Attenuation filter: Be 2mm) Fe lines sensitive to LogT=7 1% of 1-3 MK plasmas assumed 2 0.5 5 Solar-C Meeting @ St Andrews

  16. XRT Filter-Ratio Temperatures Red: AR with 10MK component Black: AR without 10MK compo. Med-Be – Thin-Be Pair (Texp = 20s / 4.3s) Ti/Poly – Al/Mesh Pair (Texp = 2.1s / 0.9s) (Narukage et al. 2011) No significant difference between with and without 10 MK component. Solar-C Meeting @ St Andrews

  17. Key Features of the Photon-Counting Soft X-ray Telescope Solar-C Meeting @ St Andrews

  18. Exposure Times with Photon Integration Mode For q = 0.45° : Single mirror piece of 120o opening angle, 8 cm paraboloid section For q = 0.9° : Single mirror piece of 68o opening angle, 20 cm paraboloid section *1: Time for accumulating 30 ke-. *2: GI telescope pixel size set to be 0.4” while XRT 1”. For q=0.45o, good Texp for FL & AR while less performance for QS & CH, for full-res. imaging. For q=0.9o, comparable Texp to XRT expected for all targets, even with full-res. imaging. Solar-C Meeting @ St Andrews

  19. Issues (Personal View) • If we can have both NI and GI as a telescope suite, it would be great. However, if it turns out not realistic, what would be the choice? • NI scientific weaknesses • What is its own science? • Little spectroscopic info. available • Can sparse wavelength bands helpful? • Can it be beyond a context imager? • Probably miss many temperature components in the corona such as AR core. Overall loop geometry not visible. • GI scientific weaknesses • Base of the corona not well addressed • Limited angular resolution (~1” vs 0.2-0.3”) • Insufficient imagery performance particularly for QS and CH with the photon-counting GI. • Question: What Solar-C can do for QS & CH ? • Who is to do? Solar-C Meeting @ St Andrews

  20. Backup Slides Solar-C Meeting @ St Andrews

  21. XIT/GI XIT/NI Solar-C Meeting @ St Andrews

  22. XIT(GI, NI) Solar-C Meeting @ St Andrews

  23. Imagery cadence ~<10 s for 171 and 304 Å Fig. 6.3-2 Solar-C Meeting @ St Andrews

  24. Three-Channel NI Layout (Figure courtesy of SAO) 171Å 94Å UV or 304Å Primary: Φ32 cm, efl=16 m Sector: Ageom≈ 100, 200, 300 cm2 Channel selection via focal plane filters! Solar-C Meeting @ St Andrews

  25. Key Features of the Photon-Counting Soft X-ray Telescope Photon counting ROI: > 200” x 400” Photon counting ROI: > 80” x 400” Solar-C Meeting @ St Andrews

  26. GI Mirror Effective Area GI#2 (0.9°) • GI #1 (0.45°) • Similar Aeff as XRT even for <2 keV • Larger Aeff than GI #1 (0.9°) for >~5 keV • Photon Counting observation • GI #2 (0.9°=XRT) • Exp. time per pixel consistent with XRT by use of a large mirror XRT(0.9°) GI #1 (0.45°) Solar-C Meeting @ St Andrews

  27. Summary NI & GI under consideration for coronal imager Solar-C Meeting @ St Andrews

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