X-ray Surveyor: Successor to the Chandra X-ray

Observatory Dan Schwartz (SAO),

For the X-ray Surveyor informal concept study team*, with material from the X-ray Vision Workship, 6-8 Oct 2015 http://cxc.harvard.edu/cdo/xray_surveyor/

The Workshop is organized by Astronomical Institute of the Academy of Sciences of the Czech Republic,

Czech Technical University in Prague andMinistry of Transport

http://axro.cz

*J. Gaskin (MSFC), A. Vikhlinin (SAO), M. C. Weisskopf (MSFC), H. Tananbaum (SAO), S. Bandler (GSFC), M. Bautz (MIT), D. Burrows (PSU), A. Falcone (PSU), F. Harrison (CalTech), R. Heilmann (MIT), S. Heinz (Wisconsin), C.A. Kilbourne (GSFC), C. Kouveliotou (GWU), R. Kraft (SAO), A. Kravtsov (Chicago), R. McEntaffer (Iowa), P. Natarajan (Yale), S.L. O’Dell (MSFC), A. Ptak (GSFC), R. Petre (GSFC), B.D. Ramsey (MSFC), P. Reid (SAO), D. Schwartz (SAO), L. Townsley (PSU)

Surveyor

1

X-ray Surveyor Mission Concept Utilize experience from Chandra,

and build on Con-X / IXO / AXSIO studies

• 3 m diameter mirrors, 10 m focal length -  30x Chandra area at E < 2 keV, -  10x at 7 keV -  Mass/Area =1/50 times Chandra

• Improved instruments: - gratings (CAT or Reflection) - active pixel imager (CMOS, wide field) - microcalorimeter 2

X-ray Surveyor Mission Status Expected to be one of 4 mission concepts for which NASA’s Astrophysics Division will fund a NASA center to study Science, Technology, and Cost over next 3 years.

Expect NASA to form a Science and Technology Definition Team (STDT) for the mission

Study will produce input for the 2020 Decadal committee to consider in its prioritization process.

The Marshall Space Flight Center (MSFC) Advanced Concepts Office (ACO) carried out previous studies with MSFC, SAO and an informal team of interested scientists*

*References: Reid et al., SPIE 2012, SPIE Proceedings, 8443, p.OT, Vikhlinin et al. , SPIE 2012, SPIE Proceedings, 8443,p.16 Weisskopf et al. SPIE 2015, SPIE.9510E..02W, and arXiv:1505.00814 Gaskin et al., 2015, SPIE Optical Engineering+ Applications , pp. 96010J

3 DAS, SAO, AXRO 15, 10 Dec 2015

How does the universe work? Origin and Fate:

First Black Holes History of galaxy formation and assembly Cluster dynamics; Feedback

Extremes of Nature: Chart warped space around distant BH Neutron star EOS BH spins; Jets

“Surveyor”: Discover and Characterize “Mapper”: Extraordinary Details

Priorities for most important scientific activities in A&Ap

Cosmic Dawn: Searching for the first stars, galaxies, Black Holes.

Physics of the Universe: Under- standing scientific principles.

Black Holes Cosmology Life cycles of energy and matter

2010 2013

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First Black Holes See review by Volonteri, 2010A&ARv.tmp....2V

• Massive Pop III stars, M>260M�, explode to form black holes.

– M⇡100 M�– LX=LEdd=1.5 10

40ergs s

�1

– FX = 10

�20ergs cm

�2s

�1at z=10

• Form in cloud, MBH=100’sM�, Mcloud=10,000’sM�Ledd is that of cloud.

(Begelman et al. 2008 MNRAS.387.1649B)

– Mcloud=3 10

3M�

– LX=LEdd,cloud=4 10

41ergs s

�1

– FX = 3 10

�19ergs cm

�2s

�1at z=10

• Direct collapse of cloud, MBH = 10

3– 10

5M�.

(Volonteri et al. 2008MNRAS.383.1079V,

Natarajan & Treister 2009MNRAS.393..838N)

– M=10

5M�

– LX=0.1 LEdd=1.3 10

42ergs s

�1

– FX = 10

�18ergs cm

�2s

�1at z=10

5

5” mirror

0.1

1.0

10

100

103

0 5 10 151×104

5×1041×105

5×1051×106

5×1061×107

Off-axis angle, arcmin

ConfusionLimit

[Sources

[deg

-2]

Confusion limited source density vs. Off-axis angle

Flux

[10-20ergcm

-2s-1

Wolter-Schwarzschild Design 6 DAS, SAO, AXRO 15, 10 Dec 2015

Strawman Surveyor Areas

7 DAS, SAO, AXRO 15, 10 Dec 2015

0 5 10 151.×10-19

5.×10-191.×10-18

5.×10-181.×10-17

Off-axis angle, arcmin

Flux

[ergcm

-2s-1.5-2keV] Flux limit for 3 or 5σ 4Ms source detection

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1 10 100 1000 10410-19

10-18

10-17

10-16

10-15

Observing time [ks]

Flux

[ergcm

-2s-1.5-2keV]

Off-axis flux limit for 5σ source detection

off-axis angle 3’ 7’

10’

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0.5 1 5 101038

1039

1040

1041

1042

1043

1044

Redshift

SourceLuminosity

[ergcm

-2s-1 ]

Sensitivity vs. redshift

10ks

100ks 1 Ms

4 Ms

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Chandra ---> Surveyor: Replace Mirrors and SI 11

DAS, SAO, AXRO 15, 10 Dec 2015

Nested Mirror Modules

AXAF

XRS

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MIT

MSFC

Thermal Forming

Con-X, IXO, AXSIO

SAO/PSU

Si Optics GSFC

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Chandra heritage: • Systems Engineering • Pointing control and Aspect • Thermal control • Test and assembly • Operations and Software • Software architecture

Major Change Impacts: Heavier SI so more massive translation/focus stages More mirror radiation area and more SI power, requires more

solar array power More x-rays: higher data rates

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Identical Requirements •  Angular Resolution

•  Pointing accurary •  Pointing stability (easier) •  Post facto image reconstruction and celestial location

•  Aspect System •  Star Camera (visible light) •  Stray Light Shade •  Fine and coarse sun sensors

•  Fiducial Lights, Retro-reflector, Periscope •  Pointing control

•  Inertial reference sensors •  Reaction Wheels, Vibration isolators •  Control laws: Pointing, Slewing, Dithering

•  Contamination Control and Monitoring •  Stray X-ray & visible light shielding for SI’s •  Mission operations and data processing •  Momentum unloading propellant tanks, valves, plumbing 15

DAS, SAO, AXRO 15, 10 Dec 2015

Similar Sub-systems •  Command, Control and Data management

•  Architecture similar, with increased storage and TM rate •  Calibration. Module level only? Only sampled Modules? •  Flight software architecture

•  Modes: Point, Bright star hold, Normal Sun, SAFE •  Sensor processing •  Algorithms: Kalman filter; Eigenaxis maneuvers; safing code

•  Translation and focus adjustment (for heavier instruments) •  Magnetic broom to deflect particles (need larger magnets) •  Sunshade door; aft contamination door, (larger) •  Larger diameter for

•  Telescope •  Spacecraft systems module •  Fore end of tapered optical bench

•  Grating insertion mechanisms •  Thermal control: Better MLI, higher aperture loss, tighter mirror specs(??) 16 DAS, SAO, AXRO 15, 10 Dec 2015

Chandra Lessons •  Science Driven, Stable Requirements •  Early assessment of key risks, and mitigation •  Cross check critical measurements •  Different Thermal Coatings – avoid increased absorptivity •  Heaters co-located with their control thermistors •  Allow aspect camera CCD to be cooled well below -20C •  Maintain avionics simulator and validation testset to verify all patches to on-board flight software •  Database structures to allow rapid (sec) access to

•  Measurements for all quantities at current time interval •  All mission data for some selected quantities •  Mission events and system states (not necessarily in TM)

•  Empirical models to predict temperatures of critical subsystems •  End-to-end ground operations testing

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Aspect Camera Concept

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Operations Flow

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X-Ray Vision Workshop October 6-8, 2015 Washington DC

http://cxc.harvard.edu/cdo/xray_surveyor/

Brainstorming session to list* 1. What Questions X-rays can best, or uniquely, address? 2. Which require X-ray Surveyor area and resolution? 3. What precursor observations can be made in advance? 4.  What modest enhancements to the current study

baseline would increase science?

* To appear on the workshop web page, G. Fabbiano, M. Elvis, eds. 20

DAS, SAO, AXRO 15, 10 Dec 2015

1.  What Questions X-rays can best, or uniquely, address?

2.  Which require X-ray Surveyor area and resolution? 21

4. What modest enhancements to the current study baseline would increase science?

•  Larger area •  Higher angular resolution (to 0.25” ?) •  Smaller calorimeter pixels •  Larger field of view •  Higher energy coverage (to 20 keV) •  Long mission lifetime •  Low background •  Agility – rapid slewing •  Increase calorimeter soft band •  Higher counting rates for calorimeter

These will all naturally be studied as part of trade-offs defining the presentation to the 2020 decadal committee, and again during the phase A study of the actual mission

22 DAS, SAO, AXRO 15, 10 Dec 2015

4. What modest enhancements to the current study baseline would increase science?

•  Larger area (trade against mass, angular resolution) •  Higher angular resolution (to 0.25” ?) (trade against area) •  Smaller calorimeter pixels (peer review of competitive SI procurement) •  Larger field of view (peer review of competitive SI procurement) •  Higher energy coverage (to 20 keV) (multilayer coating?) •  Long mission lifetime (orbit choice, L2 vs. HEO?) •  Low background (CMOS on-chip processing? Orbit choice?) •  Agility – rapid slewing (limited by ground contact. trade reaction wheel

mass, reliability, vibration) •  Increase calorimeter soft band (trade filter materials, operating T) •  Higher counting rates for calorimeter (pixel numbers, sizes,

multiplexing scheme)

These will all naturally be studied as part of trade-offs defining the presentation to the 2020 decadal committee, and again during the phase A study of the actual mission

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25 DAS, SAO, AXRO 15, 10 Dec 2015

aka Feedback

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Growth and Evolution of Structure

X-ray Surveyor will be a strong candidate for the 2020 Decadal highest priority

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