The Nuclear Spectroscopic Telescope Array (NuSTAR)

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The Nuclear Spectroscopic Telescope Array (NuSTAR)
Hard X-ray (5 - 80 keV) Small Explorer (SMEX)
mission Selected 11/2003 for a Phase A
study Downselection 11/2005 Caltech, JPL,
Columbia, LLNL, DSRI, UCSC, SLAC, Spectrum Astro
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• NuSTAR the first focusing
• mission above 10 keV
• brings unparalleled
• sensitivity,
• angular resolution, and
• spectral resolution
• to the hard x-ray band
• and opens an entirely new region of the
  electromagnetic spectrum for sensitive study

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NuSTAR has three primary science goals
NuSTAR will discover collapsed stars and black
holes on all scales as a pathfinder for the
Beyond Einstein missions
Characterize compact stellarremnants near the
Galactic center
Identify massive black holes in the NDWFS (wide -
9 deg2) and GOODS (deep-5002) survey fields
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NuSTAR will map the remnants of recent supernova
explosions, testing theories of where the
elements are born
SN 1987A
NuSTAR will measure and map the 44Ti lines at 68
and 78 keV in historic remnants Tycho, Kepler,
Cas A and SN1987A
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NuSTAR will explore the most extreme physical
environments in the Universe, teaming with GLAST
and Chandra to span the high-energy spectrum
NuSTAR will test our understanding of all types
of black-hole powered active galaxies
Example GLASTs measurements of Compton
radiation in the blazar Markarian 501 are
compromised without NuSTARs simultaneous
measurements of the time variable synchrotron
peak (SSC model is shown). Together, they
strongly constrain physical models.
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Other objectives
Study cosmic ray acceleration in young
SNR Measure high-energy diffuse Galactic
emission Detect hard X-ray emission from galaxy
clusters Map pulsar winds in the Crab Measure
cyclotron lines in Her X-1 Unravel physics of
GRBs through followup of Glast events Test models
of Type 1a Sne
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Core collapse events SNe lightcurves powered by
radioactive decay of elements produced in
non-equilibrium conditions of explosion Following
gamma-ray emission lines after core-collapse
provides critical tests of explosion models -
difficult in core-collapse events Imaging
gamma-ray emisison in a young remnant, before
they enter the Sedov phase also provides a
detailed understanding of the explostion
dynamics.
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• 44Ti - (t 85 yr) - produced near the mass cut
  during a-rich freeze-out
• Production and ejection very sensitive to
  explosion mechanism and ejecta dynamics.
• Believed to now power the 1987A lightcurve
• Gamma-ray lines at 68/78 keV, 1157 keV (detected
  by Comptel in Cas A

SN 1987A
Flux measurement 44Ti yield (inferred to be
high in 1987a) Mapping remnants measure
global asymmetries, ejecta mixing from velocity
measurements
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Line flux sensitivity - 2 x 10-7 ph/cm2/s (106
s)
Map 3 young remnants Measure asymmetry, velocity
distribution Clumpyness Measure flux from SN1987a
Remnant Age Dist Size 67.9 keV flux
(yr) (kpc) () (x 10-6
ph/cm2/s) SN 1987a 20 50 0 2.5 Cas
A 327 3.4 3.6 15 Kepler 403
2.9 3.5 8.4 (?) Tycho 435 2.3 8x5
9.2
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Type 1a Supernovae
SNe 1a widely believed to result from
thermonuclear incineration of an accreting C/O
white dwarf. We dont know nature and
evolution of the progenitor system mass of dwarf
at ignition physics of subsequent nuclear
burning reason for the (empirical) width-optical
luminosity relation The lightcurve is believed
to be powered by the decay of 56Ni A SN 1a has
never been observed in the X-ray/gamma-ray
Observations of the time evolution of the 56Ni
line (158 keV) would provide important
constraints on the explosion mechanism and
dynamics
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Prompt Decay of 56Ni i Type Ia SNe
Evolution of the 56Ni in Type Ia SNe is sensitive
to the explosion mechanism and mixing. For
example, Mch and sub-Mch models can be easily
distinguished. NuSTAR can measure evolution of
down-scattered HXR photons to Virgo.
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Ready
Although it brings new capabilities to space,
NuSTAR is solidly based on existing hardware
developed in a 9 years in a NASA SRT program
Based on the Spectrum Astro SA200-S bus, the
NuSTAR spacecraft has extensive heritage. NuSTAR
will be launched into an equatorial orbit from
Kwajalein.
The four NuSTAR telescopes have direct heritage
to the completed HEFT flight optics.
The 9m NuSTAR mast is a direct adaptation of the
60m mast successfully flown on SRTM.
NuSTAR det-ector modules are the HEFT flight
units.