Hinode XRT: An Overview

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Hinode XRT An Overview

• M. Bobra
• Harvard-Smithsonian Center for Astrophysics
• Cambridge, MA
• With contributions from the XRT Team
• (SAO, NASA, JAXA, NAOJ)
• and additional contributions from
• the EIS team (STFC, NRL, JAXA, NAOJ)
• and the SOT Team (NAO, LMSAL, NAOJ, JAXA)

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First X-Ray Image of the Sun
X-ray/EUV emission from flares suspected in
1950s -- Ellison, 1950, Pub. Royal Obs,
Edinburgh deduced EUV emission from effect on
ionosphere -- Chubb, Friedman, Kreplin,
Kupperian, 1957, Nature, 179, 861 7 years of
rocket observations, 5 X 10-3 ergs/s/cm2 from
quiet sun
-- Giacconi et al., 1965, ApJ, 142, 1274 --
spatially highly structured corona
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Skylab, 1975
Leon Golub
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Rocket Flight NIXT, 1992
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Yohkoh, 1991 - 2005
grazing incidence, 2.5 MK, monitoring through a
cycle
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The Hinode Spacecraft

• Hinode is a Japanese mission with contributions
  from the USA, UK and Europe.
• SOT A high resolution optical telescope that
  provides spectrally resolved images, Dopplergrams
  and vector magnetograms
• XRT A high resolution X-ray telescope that
  provides coronal temperature and density maps
• EIS An EUV imaging spectrometer that provides
  spatially resolved high resolution spectra.

Uchinoura Space Center Kagoshima, Japan
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Hinode Spacecraft Properties

• Mass 875 kg
• Power 1000W
• Telemetry 4 Mbps
• Data Recorder 8 G bit
• Attitude Solar pointed
• Stability 0.3 arcsec per 1s
• Launch 23 September 2006
• Orbit Polar, Sun-Synchronous, 600km

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Comparative Fields of View
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Automatic Tracking
Hinode can select and track any region on the Sun
Limb viewing
Change to new target
Polar Observation
Spacecraft pointing targets determined every
morning
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Solar Optical Telescope

• Telescope
• F9, aplanatic,Gregorian with a 50 cm aperture.
• Diffraction limited performance 388-670 nm
• Angular resolution is 0.2 at 400 nm
• The field stop restricts the FOV to 4x4 arcmin2
• The OTA also contains the polarization modulator
  for the magnetographs and the tip/tilt mirror for
  the Correlation Tracker

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Completed Optical Telescope Assembly
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The Focal Plane Package
The FPP contains three instruments a
spectropolarimeter, a broad band imager and a
narrow band imager Dimensions 1.63 x 0.65 x 0.37
m3 Mass 48.4 kg

• The Spectropolarimeter (HAO) records full Stokes
  profiles of the magnetic field
• Slit Width 1.6 x 164 arcsec2
• Spectral Range 6302.05Å
• Spectral Resolution 25 mÅ
• The Broad Band Filter Imager images the
  photosphere and chromosphere in six bands between
  380 670 nm at the highest resolution thus far
  of 0.053 arcsec pixels
• The Narrow Band Filter Imager measures vector
  magnetic fields and Dopplergrams using a tunable
  filter
• Spectral Coverage 5170 6570 Å
• Magnetic Sensitivity 5 G (long) 50 G (trans)
• Doppler Velocities 50 100 m/s

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How good is the pointing and image stability?

• The telescope is pointed using a sun sensor and
  the spacecraft provided attitude control system.
• Due to orbital variation and jitter, the pointing
  stability ranges from 0.7 arcsec/sec to 5 arcsec
  per hour.
• To recover the diffraction limited performance
  for the OTA, a correlation tracker controls a
  tip-tilt mirror located in the collimated beam
  exiting the OTA. The combination improves the
  expected image stability for the OTA/FPP to
  0.06 arcsec/10 sec and 2 arcsec per hour.

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EUV Imaging Spectrometer

• The EIS is a joint effort between MSSL and NRL.
• EIS provides temperature and density diagnostics
  of coronal and transition region plasmas and will
  attempt to detect reconnection flows.
• Properties
• Wavelengths 170-210 Å, 250-290 Å
• Resolution Spatial 1.0 arcsec pixel Spectral
  2.23 mÅ/pixel
• Slits1 x 512 and 2 x 512 arcsec2
• Slot 40 x 512 and 250 x 512 arcsec2

EIS final preparations
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The X-Ray Telescope

• XRT Properties
• Optics - Wolter I Grazing Incidence Telescope
• Focal Length 2700 cm
• Geometric Area 5 cm2
• Shutter/Analysis Filters
• texp 1ms to 16s
• 9 X-ray, 1 G-band filter
• 1-30 MK temperature response range
• Camera
• 2048x2048 CCD
• 1 arcsec pixels

The XRT is a collaborative effort between SAO
(mirror, filters, structure, mechanical systems)
and ISAS (camera sensor and electronics).
Mounting the XRT to the spacecraft
XRT Diameter 0.42 m Mass 48.4 kg
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XRT Grazing Incidence Light Path
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Filter Wheels
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Temperature Response
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XRT Science Goals

• Coronal Mass Ejections
• Coronal Heating
• Reconnection and Jets
• Flare Energetics
• Photospheric-Coronal Coupling

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XRT Observation Modes

• Dynamics
• Rapid evolution associated with reconnection and
  plasma instabilities
• High Cadence
• Energetics
• The thermal evolution of structures heating
  cooling
• The emission measure evolution of structures up
  flows down flows
• Multiple filters
• Topology
• Identify the magnetic connections that control
  the heating and dynamics
• Large FOV, long and short exposures

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XRT First Light
28 October 2006
Hinode XRT Quiet Sun
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28 October 2006
Hinode XRT False Color
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?????X???????????
5 arcmin 220,000km)
30 arcsec 22,000km)
30 arcsec 22,000km)
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SXT and XRT comparison
Trish Jibben
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Al-Poly Filter
Al-Poly
Trish Jibben
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C-Poly Filter
C-Poly
Trish Jibben
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Be-Thin Filter
thin-Be
Trish Jibben
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XRT Shows Extent of Structure Surrounding ARs
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A typical corona (QS small AR) requires gt104
dynamic range
Combined 4s 0.5s XRT exposures, Thin Al filter.
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Fine details in active regions
1 arcmin
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B vs. X
MDI Magnetogram
XRT Thin Ti, 1 sec., 11/04/06
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Photosphere-corona observations with SOT
XRT v. SOT G-band 14 November 2006 Magnetic Field
bifurcation over light bridge
Jonathan Cirtain
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Detailed Views of AR from XRT
Small AR near CMP
Thin Al/Poly 1 sec
Jonathan Cirtain
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Cavity structures seen at limb
Trish Jibben
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Synoptic Sun-Center program
Trish Jibben
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TRACE and XRT are complimentary
TRACE 11/13/06
XRT 11/13/06
Leon Golub
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AR 10930 in X-1.5 Flare (Be-Thin)
Monica Bobra
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Downflows seen in active region
David McKenzie
Note highly sheared inner and unsheared outer
loops in flaring region.
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EIS view of shrinking loops at limb
David H. Brooks
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EIS Slit Raster Movie
David H. Brooks
I
Distance
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TRACE shrinking loops movie
Kathy Reeves
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Combined SOT - XRT Observations
Joten Okamoto
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Polar Jets - Numerous Events
Trish Jibben
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Polar Jets - Theory
Shimojo, M., and Shibata, K., ApJ 542, 1100 (2000)
From the Hudson Solar Cartoon Archive
(http//solarmuri.ssl.berkeley.edu/hhudson/cartoo
ns/overview.html)
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Total Solar Eclipse - 19 March 2007
Kano Ryouhei - XRT CO
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Transit of Mercury Mosaic 8 November 2006
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On-orbit measurement of PRFM. Weber and XRT Team
XRT Al_poly/Open 08-Nov-06 235031 16.39s
512x5121 pixel 1 arcsecondMercury traversed
the FOV horizontally about 1 arcsec during this
16.4 sec exposure. Mercurys angular diameter
10 arcsec.Analysis of three columns of pixels
perpendicular to planetary velocity.
Surface plot of intensity inside the subregion
box.Mercurys shadow has an obvious effect.Edge
blurring along the direction of velocity is
minimal, but we analyzed three columns in the
perpendicular direction anyway.
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On-orbit measurement of PRF(M. Weber and XRT
Team)
Light-curves along 3 central columns through
shadow.The mean of these curves is analyzed on
the right (Northern) edge. We varied the sigma
of a 2D Gaussian convolved with a 2D circular
step-function shadow to fit the drop-off.
Intensity
Arcseconds (along Y-axis)
Dashed line mean of three columns in previous
plot.Diamonds data points used for fitting the
model.Error bars on data deviation of data
about mean (probably a bit generous).Solid line
best model fitBest fit Gaussian sigma of 0.6
/- 0.07 arcsec.FWHM 1.0 /- 0.12 arcsec
Mean Intensity
Arcseconds (along Y-axis)
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Downloading XRT and SOT Data

• Virtual Solar Observatory
• http//sdac.virtualsolar.org/cgi-bin/search
• Lockheed Martin Data Repository
• http//sot.lmsal.com/sot-data
• Hinode XRT Observing Proposals
• http//solar.physics.montana.edu/HINODE/XRT