1 / 27

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

aya
Download Presentation

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

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  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 EUVST • 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 EUVST 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 EUVST 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

More Related