XEUS Xray Evolving Universe Spectroscopy Mission

1
XEUS (X-ray Evolving Universe Spectroscopy
Mission)
Owen Rees Williams

• Potential follow on to ESAs cornerstone X-ray
  spectroscopy mission (XMM-Newton).
• Under study as envisaged by the Horizons 2000
  Survey Committee. Recommended analyzing XEUS as a
  potential utilization of the International Space
  Station (ISS) for high-energy astrophysics
  applications.
• XEUS will be a long-term X-ray observatory
  providing a telescope aperture equivalent to the
  largest ground-based telescopes.

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XEUS Scientific Objectives

• What are the main topics for high energy
  astronomy at the end of the decade?
• Study of the formation of the first massive black
  holes.
• Study of the large scale structure of the
  Universe and in particular any hot filamentary
  component.
• Study of the first small groups of galaxies and
  their evolution to todays massive clusters.
• Study of the formation of the abundant elements,
  in particular in hot intra-cluster gas.

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XEUS Mission Concept

• XEUS will provide a major leap forward in
  capability
• 30 m2 of collecting area (fully grown), 6 m2
  (zero growth) at 1 keV
• 3 m2 at 8 keV and 1000 cm2 at 20 keV
• Imaging resolution with a goal at 1 keV of 2 HEW
  (Half Energy Width)
• A limiting sensitivity of 4 10-18 erg cm-2 s-1
  about 250 times deeper than XMM-Newton
• Spectral resolution with a goal of 1 eV at 1 keV
  (specification 2 eV)
• Broadband coverage between 0.05 and 30 keV
• A field of view of 5 arc minutes

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XEUS Scenario
XEUS 1
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XEUS Key Parameters
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XEUS Mirror Spacecraft Design (MSC1)
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XEUS Mirror Growth at the ISS

• Schematic figure showing the increase in
  mirror aperture between the zero-growth (MSC1)
  and final configurations (MSC2)

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XEUS Increase in Mirror Area at the ISS

• The XEUS mirror area for a 50 m focal
  length. The solid line shows the mirror area in
  the extended configuration, with 5 mirror rings.
  The dashed line shows the mirror area in the
  initial configuration, when only two mirror rings
  are present.

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XEUS Detector Spacecraft Design
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XEUS Instruments
70 x 70 mm2 0.1 - 30 keV 50 eV FWHM _at_ 1 keV 75 ?m
position resolution 70 ?s timing resolution QE gt
90 for E gt 280 eV Top 280 K
Large field-of-view imaging spectrometer Semicond
uctor based (e.g. DEPFET array)
7 x 7 mm2 0.05 - 7 keV, 0.5 - 15 keV 3 eV (goal 1
eV) _at_ 1 keV 150 ?m position resolution 1 ?s
timing resolution 10 kHz/pixel 20-90 mK, 15-30 mK
High energy resolution imaging
spectrometers Cryogenic (STJ-based and/or
bolometer array)
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XEUS Sensitivity Comparison

• The sensitivity of XEUS is well matched to that
  of the new generation of observatories working in
  other wavebands.
• ?F? plot, so a horizontal line corresponds to
  equal power per decade of frequency. The black
  lines show the output from 3C273 at z 10 and z
  20.

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XEUS - Limiting Sensitivities

• LogN/LogS relations, derived from the simulated
  images, for the initial and final XEUS
  configurations, with different PSFs, using a
  simple detection algorithm. Dotted lines show the
  input distribution.

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XEUS Spectral Resolving Power
Credit F. Paerels

• Plot of resolving power against photon energy.
  The red line shows the resolving power of the
  strawman TES instrument green the strawman STJ
  instrument.