ESTREMOWFXRT Workshop

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The Wide Field Monitorfor ESTREMO/WFXRT A
Summary of the 2-3 August Thinkshop

• Marco Feroci
• IASF/INAF Rome

2
(Very) Minimum (baseline) requirements for WFI()

• Requirements for the localizator are
• Flux rather bright events (gt1 Crab)
• Energy range need to go down to at least 4 keV.
  Upper range not a driver for localization (but
  see below), 40 keV should be good enough.
• FOV gt 3-4 sr
• Localization (driven by NFI) better than 3
  arcmin
• Need to have at least the temporal signature in
  the hard X-ray range (gt100 keV) to identify a
  GRB

() Presentation by L. Piro
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Additional Requirements for WFI Study of the
prompt emission of GRBs

• See L. Amati

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Gross Hardware Constraints()

• Mass 150 kg, including cont.y
• Power 120 W, including cont.y
• Volume 70 cm height,
• Vega fairing (220 cm) symmetric
• Telemetry few Mbit/s (X-band)

() Presentation by L.Piro
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Designs Proposed for WFM

• ISGRI/BAT-like configuration, with optical design
  and detector technology to be assessed (open
  field det.)
• Improved SuperAGILE technology, plus classical
  open-field spectroscopy detector
• Both options satisfy the baseline scientific
  requirements.
• Option (a) offers better performance for the
  study of the prompt emission of GRBs and (Hard)
  X-ray transients, simultaneously over half sky
  probably unprecedented.
• high quality ASM science
• Option (b) requires smaller budgets (factor of
  2-3) but provides coarser spectral info on prompt
  emission.
• Soft X-rays (1-5 keV) probably require SDD in
  both options.
• Fine determination of spectral parameters
  requires area or small FOV for the spectroscopy
  detector.

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Option (a) (baseline)

• 2D pixellated detector pixel size ?2-3 mm
• Energy range 1/10 200 keV, depending on
  technology
• Detector options CZT, CdTe, SDDCsI
• Geometric Area ?3700-5000 cm2, depending on
  solution
• Eff. Area ?350 (flat) or ?700-2500 cm2
  (min/max), dep. on solution
• 2D Coded Mask
• Mask-Detector distance ?400-700 cm, depending on
  solution
• FOV 3-6 sr, to be optimized
• Angular Resolution ?30-40 arcmin
• Point Source Location Accuracy ?2-3 arcmin
• Sensitivity (1s) ?0.5-5 Crab, to be optimized
• Weight ?150 kg
• Power ?120 W

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Option (b) (back-up)

• Detector 1D microstrip pixel size ?120 ?m
• Energy range 3-5 50 keV, depending on ASIC
  technology
• Detector options Silicon, ?1-2 mm thick,
  single/double-sided
• Geometric Area ?5000 cm2
• Eff. Area ?100/200 cm2 (any direction), dep. on
  solution
• 1D/2D Coded Mask
• Mask-Detector distance 15 cm
• FOV 6 sr, to be optimized
• Angular Resolution ?6 arcmin
• Point Source Location Accuracy ?1-2 arcmin
• Sensitivity (1s) ?1 Crab, to be optimized
• Weight ?30-50 kg
• Power ?50 W

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Summary of Solutions
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Summary of Summaries

• Arcmin Localization of bright bursts (say, 50
  events/year) in 10-100 keV easily reachable
• Good low energy (lt5-7 keV) sensitivity requires
  RD or dedicated detector
• Good high energy (gt200 keV) spectral sensitivity
  may require dedicated detector
• Good spectral response on wide energy range (fine
  determination of spectral parameters) may require
  trade-off on the area/FOV. Different optimization
  wrt point (1)
• Need A Clear Assessment of Scientific
  Requirements