The FORCE mission:
focusing
onrelativistic universe andcosmicevolution

Koji Mori(University of Miyazaki, Japan)
on behalf of the FORCE collaboration

The FORCE mission:
A broadband X-ray
imaging spectroscopy
in 1-79 keV
withhigh-angular resolutionof < 15 arcsec

Koji Mori(University of Miyazaki, Japan)
on behalf of the FORCE collaboration

FORCE collaboration members•
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H. Murakami (Tohoku Gakuin)
T. Enoto (RIKEN)
Y. Terada (Saitama)
T. Takahashi (Kavli IPMU/Tokyo)Y. Uchiyama (Rikkyo)
A. Bamba, H. Odaka (Tokyo)
A. Kubota (Shibaura tec)
Y. Yatsu (Tokyo tec)
T. Ohashi (Tokyo Metropolitan)
T. Kohmura, K. Hagino, S. Kobayashi (Tokyo sci)
T. Kitayama (Toho)
M. Ishida, S. Watanabe, R. Iizuka, H. Yamaguchi (ISAS/JAXA)
K. Ishimura (Waseda)
H. Nakajima (Kanto Gakuin)
K. Nakazawa (Nagoya)
A. Furuzawa (Fujita health)T.G. Tsuru, Y. Ueda, T. Tanaka, H. Uchida (Kyoto)
M. Itoh (Kobe)
M. Nobukawa (Nara edu)
K.K. Nobukawa (Nara women’s U)
H. Matsumoto, H. Noda, H. Tsunemi (Osaka)
Y. Fukazawa, T, Mizuno, H. Takahashi, M. Ohno (Hiroshima)
H. Awaki, Y. Terashima (Ehime)
K. Mori, A. Takeda (MIyazaki)
H. Akamatsu (SRON)
A.E. Hornschemeier, T. Okajima, W.W. Zhang, B.J.Williams, T.M. Venters, M. Yukita, R. Petre (GSFC/NASA)

March 9th, 2021

26 institutes,
48 members

HEAPA meeting3

Scientific Goals
Intermediate
mass BH（102-4 Msun）

Buried Super-massive BH(>104 Msun）

stellar-mass
BH（<102 Msun）© Ute Karus© NASA© NASA

© NASA© ESO/M. Kornmesser© NASASupernovaexplosions•Major merger ofClusters ofgalaxies

Forward andreverse shocks
at SNRs

Our scientific goals are– to complete a census of black holes across cosmic time and mass scale,– to measure the energetic content of relativistic particles in the universe, and– to understand the explosion mechanism and nucleosynthesis in supernovae

March 9th, 2021

HEAPA meeting4Probing Co-evolution of galaxies andtheir SMBH by buried AGN
Hopkins +06

mass ofSuper-Massive BH

Gueltekin +09velocity dispersion in galaxy• “Co-evolution” of galaxies and their SMBH
• Buried, Compton-thick AGNs may be in rapidly
growing phase of SMBHs and play a key role tounderstand the galaxy-SMBH evolution
March 9th, 2021

HEAPA meeting5

Hard X-ray census ofCompton-thick AGNs
Ueda+ 07•••

Ricci+16

The brighter CTAGNs have been studied with Suzaku non-imaging
hard X-ray detector
The NuSTAR’s hard X-ray imaging is discovering a fainterpopulation
One-order magnitude deeper hard X-ray sensitivity to point sources
is required to reveal how the CTAGN fraction evolve in cosmic time

March 9th, 2021

HEAPA meeting6Particle acceleration in Supernova
Remnants / Clusters of galaxies
Simulated FORCE spectrum: 1 Msec

Tanaka+18

Inverse Comptonstrongest•

Supernova remnants––•

Clusters of galaxies––•

What is the total energy of cosmic rays that each SNR can produce is an unresolved question
Nonthermal bremsstrahlung, recently discovered in the SNR W49B in the hard X-ray band (left figure), isa new window to study sub-relativistic particles accelerated in SNRs
Origin of the cosmic magnetic field and the total content non-thermal energy in the Universe are notunderstood, and the measurements of particle energy and magnetic field over the cluster scale aredemandedCombination with synchrotron radio data, the detection of the inverse Compton emission in the hard Xray band gives the energy spectrum of relativistic electrons and the magnetic field (right figure)

Unprecedented Hard X-ray sensitivity to diffuse sources is also required to achieve these goals
March 9th, 2021

HEAPA meeting7Mission requirements anddesign parameters• High sensitivity in the hard X-ray band above 10 keV– 2-3x10-15 erg/s in 10-40 keV• Broadband response– simultaneous coverage of the soft and hard X-ray bands isessential to study intrinsically time-variable AGNs

• Large effective area

March 9th, 2021

HEAPA meeting8

X-ray image with HPD 15” in thehard X-ray band••

NGC 253, bright, nearby, and one of the best-studied starburst
galaxies
Left image shows 495 ks NuSTAR image whereas right image
shows ~400 ks FORCE image as expected from the current design

March 9th, 2021

HEAPA meeting9Overview of the FORCE satellite••

12 m focal length
Two identical pairs of an X-ray
super-mirror and a wideband X-raydetector

Wideband Hybrid X-ray Imager (WHXI)ü New Si sensor (SOI-CMOS) + CdTe hybrid
ü Low BG with active shield, the same
concept as the A-H’s hard X-ray
detector
ü Wideband sensitivityof 1-80 keV

X-ray Super-mirror
ü Light-weight Simirror provided
by NASA/GSFCü Multi-layer coating directlyon the Si mirror surface
ü Angular resolution of <15” in hard X-ray

March 9th, 2021

HEAPA meeting10Wide-band Hybrid X-ray Imager• Si + CdTe Hybrid detector with active shield– The same concept as the ASTRO-H Hard X-ray Imager, low cost andlow risk

• Replacing Si top layer from strip to SOI-CMOS pixel detectors– Low readout noise is achievable, lowering the energy threshold down
to 1 keV– similar working temperature to that of CdTe
– anti-coincidence technique can be utilized thanks to good timeresolution and self-trigger function
March 9th, 2021

HEAPA meeting11Hard X-ray performance of a pairof silicon mirror segmentsa mirror module
consisting of a pair ofsilicon mirror segmentswith Pt/C depthgraded multiplayer
coating

X-ray image reflected by a central
portion of the mirror module

Encircled Energy
Function

Intensity

Point spreadfunction••

The hard X-ray performance of a mirror module consistingof a pair of silicon mirror segments with Pt/C depth-graded
multiplayer coating was measured at SPring-8
The HPDs are 5 and 6 arcsec at 15 and 30 keV, respectively
at the central portion of the mirror

March 9th, 2021

HEAPA meeting

12Comparison with other X-ray missions
104

Effective Area (incl. QE)
Red:FORCE, Green:XRISM, Blue:ATHENA, Orange:NuST(best, 2 tel.)Athena FORCEXRISM (Resolve)

FORCE

1000
100
10Effective Area (cm2)

ATHENA (XIFU)NuSTAR (FPMA+B)

XRISM

1

10Energy (keV)

NuSTAR

100• FORCE encompasses NuSTAR in all the directions of
the performance radar chart (right) and plays acomplementary role to XRISM/Athena (both figures)
March 9th, 2021

HEAPA meeting13

Summary• FORCE (Focusing On Relativistic universe andCosmic Evolution) is a concept of next Japanese
medium-class mission, characterized by broadband(1-79 keV) X-ray imaging spectroscopy with highangular resolution (<15”)• FORCE will trace the cosmic evolution of black
holes in the entire range of the mass spectrum,
reveal the nature of relativistic particles at various
astrophysical shocks, and shed a new light on
the explosion mechanism and nucleosynthesis
in supernovae• FORCE is an international collaborative mission
between JAXA and NASA
• We are proposing this mission to be realized in late
2020s/early 2030s
March 9th, 2021HEAPA meeting14

May the force be with you

March 9th, 2021

HEAPA meeting15