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Solar-B XRT Initial Science Observations

Discover the capabilities and observational constraints of the X-Ray Telescope (XRT) on the Solar-B spacecraft, including its mirror diameter, focal length, and filters. Explore the XRT "firsts" and the XRT team's early science operations and goals.

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Solar-B XRT Initial Science Observations

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  1. Solar-B XRT Initial Science Observations Ed DeLuca for the XRT Team XRT Team

  2. X-Ray Telescope Mirror inner diameter: 35 cm Focal Length: 2700 cm Geometric Area: 5 cm2 Shutter/Analysis Filters texp: 2ms to 10s 9 X-ray, 1 WL filter Camera 2K2K back-illuminated CCD 1 arcsec pixels (13.5mm) XRT Instrumentation XRT Team

  3. XRTComponents XRT Team

  4. Optical Path X-Ray Mirror Shutter & filter wheels Visible Light Optic Focus Mechanism XRT Team

  5. Grazing Incidence Mirror XRT Team

  6. Focal Plane Filter Wheels XRT Team

  7. Analysis Filter Set XRT Team

  8. The XRT “Firsts” New XRT Instrumental Capabilities: • Unprecedented combination of spatial resolution, field of view, and image cadence. • Broadest temperature coverage of any coronal imager to date. • High data rate for observing rapid changes in topology and temperature structure. • Extremely large dynamic range to detect entire corona, from coronal holes to X-flares. • Flare buffer, large onboard storage, and high downlink rate provide unique observing capability. XRT Team

  9. Observational Constraints • Our science program can be addressed by three basic types of XRT observations. These must be optimized subject to our data rate (~ 0.5 Gbyte/day - assuming 15 contacts, 8min/contact, 15% allocation) • Thermal structure & energetics • 3-7 filters used per target region • May limit cadence or FOV to stay within the data rate. • Dynamics • Fast cadence with 1 or 2 filters • May limit context images or FOV to stay within the data rate • Morphology / Topology • Large FOV, combine long and short exposures • May limit number of filters, cadence or FOV XRT Team

  10. XRT Initial Observations Basic Philosophy: Start simple, have a written plan before starting, stick to the plan • Disk center • All filters, AEC tests, cadence, compression … • White light images with VLI - • Check stability over orbit • Develop aspect calibration • Limited flare response • Track a region • Follow a region for several days (disk passage) • Explore different filter combinations • Verify aspect solution as SC position wrt the sun changes • Limited flare response • Quiet sun studies • X-ray bright points • Coronal holes • Polar investigations • Limited flare response • Baseline 15 ground contacts/day XRT Team

  11. Early Science Operations Assume a modest AR on disk • Follow AR across disk • Large FOV images with all filters - very limited cadence (1536x1536, ~900 images/day, 1-2 days) • Medium FOV images with two filters plus context (1024x1024, ~2000 images/day, 1-2 days) • Small FOV images one filter plus context (768x768, ~3600 image/day, 1-2 days) • High cadence on filter small fov, selected for short exposure time (512x512, 3sec cadence, 8200 images, combine with low data rate program, 1-2 days) XRT Team

  12. Early Science Operations Assume a dynamic AR on disk • Flare buffer check, set flare trigger at low level, single filter response with high cadence (512x512), • Follow AR across disk, flare program loaded • Large FOV images with all filters - very limited cadence (1536x1536, ~900 images/day, 1-2 days) • Medium FOV images with two filters plus context (1024x1024, ~2000 images/day, 1-2 days) • Small FOV images one filter plus context (768x768, ~3600 image/day, 1-2 days) • High cadence on filter small fov, selected for short exposure time (512x512, 3sec cadence, 8200 images, combine with low data rate program 1-2 days) XRT Team

  13. Early Science Operations Assume no AR on disk • Large FOV images with 3-5 filters - very limited cadence (1536x1536, ~900 images/day, 1-2 days) • Coronal Hole on Disk? • Track evolution of boundary, select a single filter that images the plasma near the boundary well. (1024x1024, ~2000 images/day). Move SC pointing to image different parts of CH boundary with SOT. (3-5 days) • Filament on Disk? • Track filament for 1-2 days. Long exposures in 1 or filters to show magnetic structure around filament (1024x1024, ~2000 images/day). XRT Team

  14. Early Science Operations Assume no AR on disk • XBP • Thermal structure - Multi-filter study of bright points (1024x1024, ~2000 images/day). Do different filters show different structure? (1-2 days) • Dynamics - one or two filters limited FOV track existing XBP to end of life (512x512, ~8200 images/day, 2-day continuous) • Statistics - life cycle of multiple XBPs. One or two filters (1536x1536, ~900 images/day) track center of FOV for 3-4 days. XRT Team

  15. XRT Science Goals • Coronal Mass Ejections • Coronal Heating • Reconnection and Jets • Flare Energetics • Photospheric-Corona Coupling XRT Team

  16. Critical science questions • Flares & Coronal Mass Ejections. • How are they triggered, and what is their relation to the numerous small eruptions near emerging flux regions? • Flare Onset Program - Carbon or Thin Be filter, 3s cadence, (512”x512”); Al-Poly, Thin Be or Carbon, Med. Be, 40s context, (1024”x1024”). Use Flare buffer. • CME over the solar-limb with wide FOV - (2048”x2048”) with 4”x4” resolution, Al-Poly, C, 1min cadence • What is the relationship between large-scale instabilities and the dynamics of the small-scale magnetic field? • Coronal heating mechanisms. • What is the thermal structure of AR loops? • DEM - hi-res - Al-Poly, C, Thin Be, Med. Be, Med. Al, 60s cadence, (1024”x1024”). • TRACE observes loop oscillations associated with flares (Nakariakov et al. 1999). Are other wave motions visible? Are they correlated with heating? • Do loop-loop interactions contribute to the heating? XRT Team

  17. Critical science questions • Reconnection & coronal dynamics. • Yohkoh observations of giant arches, jets, kinked and twisted flux tubes, and microflares imply that reconnection plays a significant role in coronal dynamics. With higher spatial resolution and with improved temperature response, the XRT will help clarify the role of reconnection in the corona. • Filament activation - Al-mesh, Al-poly, C, Thin Be, 60s cadence, (1024”x1024”). • Solar flare energetics. • Although Solar-B will fly at solar minimum, there will still be flare events seen. The XRT is designed so that it can test the reconnection hypothesis that has emerged from the Yohkoh data analysis. • Photosphere/corona coupling. • Can a direct connection be established between events in the photosphere and a coronal response? To what extent is coronal fine structure determined at the photosphere? • XBP - one of (Al-p,C, Thin Be), 10s cadence, (768”x768”); 5 other filters (Al-p, C, Thin. Be, Med. Be, Med Al, Thick. Al), 120s cadence. XRT Team

  18. XRT Team

  19. All plans and observations will be conducted jointly with EIS & SOT Synoptic program is currently undefined XRT Team

  20. End Presentation XRT Team

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