MAXIM: The Blackhole Imager

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MAXIM The Blackhole Imager

• Keith Gendreau
• Study Scientist
• Code 662
• NASA Goddard Space Flight Center

Fiscal Year 2002 IRAD ColloquiumScience and
Technology Accomplishments Dec. 2002
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Science Driver for MAXIM

• Current best estimates for the size of the event
  horizon of a blackhole a few microarcseconds
• Variability and spectral data describe an x-ray
  bright region near the event horizon.
• Baselines at 1-10Å are a factor of of 1000
  shorter than at 1000-10000Å
• The MAXIM mission will have resolution of 0.1
  ?as.
• Resolve the event horizon
• Study physics and dynamics of inner accretion
  region near event horizon
• For Scientific and Technical context, we are
  exploring MAXIM Pathfinder mission concepts.
• Discover where AGN Jets take off
• Study Stellar Coronae

http//maxim.gsfc.nasa.gov
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Science Driver for MAXIM
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Supermassive Blackhole Targets

• The distances are calculated assuming a Hubble
  constant of 65 km/s/Mpc. Accurately determined
  kinematic black hole masses are denoted by an
  asterisk. All other black hole masses are
  estimates based upon reverberation experiments or
  host galaxy properties. All of these sources are
  known to possess variable fluxes we quote a
  typical value in the 2-10 keV bandpass.

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Objectives for FY02

• Testbed Development
• This year we planned to get fringes in 1-D of a
  scaled version of the MAXIM X-ray interferometer
  at 1 keV
• Test tolerances of a grazing incidence
  interferometer
• Advance Mission Concepts
• Make the Pathfinder mission true stepping stone
  to the full mission
• Look for new methods to point micro-arcsecond
  imagers
• Identify technological tall Poles

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Accomplishments for the Year Testbed Development
and Results

• Detected fringes _at_ 0.525 keV (23 Å) and 1.49 keV
  (8.35 Å) with a 650 micron baseline (0.1 at
  1.49 keV)
• There are several significant implications of
  this years work
• We have demonstrated interferometry over a factor
  of 3 of wavelength within the X-ray band.
• Our measurement at 8.35 Å is the shortest
  wavelength light to have produced fringes in a
  broadbandpass interferometer.
• We have successfully proven a core MAXIM concept

Fringes at 8.35 Å 25 November 2002
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Accomplishments for the Year Testbed Development
and Results
L
d
Beams Cross
Flats
Detector

• Grazing Incidence softens tolerances by 2
  orders of magnitude. Optics that are diffraction
  limited for normal incidence UV is diffraction
  limited for grazing incidence X-rays.
• Use simple optics to keep diffraction limit.
• Demonstrated in lab at 10 Angstroms (1.25 keV).
  W. Cash et al, Nature 407 14 September 2000
• Demonstrated at GSFC with 23.6 Angstroms
  27September 2002

s
Fringe Spacing
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Accomplishments for the Year Testbed Development
and Results

• Penthouse of Bldg 2
• 80 m long X-ray beam line
• 25 m source to optics
• 50 m focal length
• 1mm baseline
• (0.25 arcsec at 1 keV)

• Fringe Spacings of 75 to 250 microns-gt simple
  vibration suppression at 3 stations

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Accomplishments for the Year Mission Concept
Development (I)

• Improved Grouping of Mirrors Periscope Pairs
• Easy Formation Flying (microns)- It was
  nanometers
• All s/c act like thin lenses- Higher Robustness
• Possibility to introduce phase control within one
  space craft- an x-ray delay line- More
  Flexibility
• Offers more optimal UV-Plane coverage- Less
  dependence on Detector Energy Resolution
• Each Module, self contained- Lower Risk.
• Offers the Pathfinder Mission higher resolution
  than in our baseline mission
• Makes the Pathfinder Mission scalable towards the
  full Blackhole Imager
• Completed an IMDC Study using this concept along
  with new pointing techniques for new scalable
  MAXIM-gt cost est 550-600M

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Accomplishments for the Year Mission Concept
Development (I)
Improved Mirror Grouping
Pre FY02 Baseline Mirror Grouping
Group and package Primary and Secondary Mirrors
as Periscope Pairs

• Easy Formation Flying (microns)
• All s/c act like thin lenses- Higher Robustness
• Possibility to introduce phase control within one
  space craft- an x-ray delay line- More
  Flexibility
• Offers more optimal UV-Plane coverage- Less
  dependence on Detector Energy Resolution
• Each Module, self contained- Lower Risk.

Full MAXIM- the black hole imager

• Nanometer formation flying
• Primaries must point to milliarcseconds

A scalable MAXIM concept.
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Accomplishments for the Year Mission Concept
Development (I)
1 km
Science Phase 2 High Resolution (100 nas)
Science Phase 1 Low Resolution (100 mas)
Launch
200 km
20,000 km
Transfer Stage
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Accomplishments for the Year Mission Concept
Development (II)

• Line-of-Sight Alignment Pointing sub
  milli-arcsecond telescopes
• Needed to find alternates to using SIM as a star
  tracker
• Completed an ISAL study for the super
  startracker
• Compared traditional star tracker approaches to
  inertial reference frame approaches
• Identified specific challenges
• Found that High Precision Gyroscopes may be
  the solution
• Started a new collaboration with UMD on Super
  Fluid Gyroscopes
• Could offer higher sensitivity and a much higher
  bandpass than the GP-B gyros
• Multiple uses

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Future Work X-ray Interferometry Testbed

• Improve stability of testbed with more thermal
  control
• Attempt to lock in on fringes
• Extend the wavelength range of our testbed to the
  Iron K X-ray line
• Interferometry at less than 2 angstroms- an
  extension of more than an order of magnitude
• Our interferometer will work at wavelengths where
  we know the inner regions of a blackhole are
  bright
• We will need a longer facility
• Extend testbed to 2-D
• Bring into phase a 3rd set of mirrors
• Make larger mirrors
• Integration with the Formation Flying Testbed
• Compensate for building motion
• Provide more definition for mission concept
  studies