HiZ-GUNDAM

High-z Gamma-ray bursts for Unraveling the Dark Agesand Extreme Space Time Mission
ガンマ線バーストを用いた初期宇宙・極限時空探査計画
HiZ-GUNDAM
米徳大輔, 三原建弘A, 土居明広B, 坂本貴紀C, 有元誠, 津村耕司D,松原英雄B, 澤野達哉, 郡司修一E, HiZ-GUNDAM チーム
金沢大, 理研A, 宇宙研B, 青学大C, 東京都市大D, 山形大E

・ Competitive M-class mission (Epsilon mission) in JAXA・ Launch target is ~2030
ASJ Annual Meeting @ Nagoya University (2023/09/20 – 22)

1

Time Domain Astronomy
z=1000z=12z=7z=6z=0.5
z=0・Gamma-Ray Burst (GRB)
First Stars (Pop-III)
Cosmic Reionization
Chemical Evolution
・Gravitational Wave
(Short GRB?)
NS-NS, NS-BH (+ BH-BH)
kilonova
・TeV/PeV neutrino
・SN Shock Breakout
・Tidal Disruption
・Fast Radio Burst・AGNetc.
・Stellar Flare・Galactic Transients 22

HiZ-GUNDAM： Promotion of Time Domain Astronomy
Key Science 1: Multi-Messenger Astronomy

Combination ofX-ray and NIR

Blackhole formation and evolution,
Energy transition from gravity to particle/radiation(1) High energy transients associated with GW/ν(2) Energy transition from Gravitational energy toJet à Cocoon à Kilonova and particles(3) Abundance of Heavy elements (>> Fe)
Diversities of kilonova and E-M counterpart

Key Science 2: Exploration of early universe with GRB
Selection of High-z GRBs,
Rapid spectroscopic obs.
with large area telescopes

Planck HP(1) GRB rate at z > 7(2) Cosmic reionization history(3) Chemical evolution(4) Survey of Pop-III GRBs
3

HiZ-GUNDAM (High-z Gamma-ray bursts for Unraveling the Dark Ages Mission)
Mission： Time Domain Astronomy“Exploration of the early universe” and “Multi-messenger astronomy”

Competitive M-class
HiZ-GUNDAM

2030 –Observation strategy(1) Discovery of GRBs/transients with the wide field X-ray monitor(2) Automatic repointing(3) Identification of counterpart with the near infrared telescope(4) Alert message(5) Spectroscopic observation with large area telescopes

We will discover treasured targets from a large amount oftransient sources, and provide them as important targets
to large area telescopes. We will promote"early space exploration" and ”MM astronomy"
with all the power of astronomy.
JWSTSpace telescope

Subaru8m-class

Alert

Wide Field X-ray Monitor
・ Lobster Eye optics
・ pnCCD
Near Infrared Telescope・ 5-band photometry

TMTE-ELT

Future 30m-class

GMTDown Selection Result
・ Down selection review in Apr. – June, 2023
・ We are not selected but still surviving.
・ Down selection review again in the end of FY2023.
- Satellite specialized for downlink alert.
- Realtime uplink alert will not be supported.
(delayed uplink in normal operation is in our scope.)- Several methods are being considered in parallel.
(KSAT, Comm. satellite network (Inmarsat etc.), SVOM-VHF)- The mission scope should be extended tothe acquisition of scientific results from the large telescope.
- Establish ”Follow-up team” in HiZ-GUNDAM- Start discussing with large area facilities and users.
5Wide Field X-ray Monitor

Lobster EyeOptics

FocalImage

Near Infrared TelescopepnCCD

9/21(Thu.) V326b: Sugimoto’s talk9/22(Fri.) V349a: Goto’s talk
Items
Energy band (keV)
Telescope type
Number of Unit
Field of View
Number of modules
Sensitivity
Position accuracy

Parameters
0.4 – 4 keV
Lobster Eye Optics
6> 0.5 str (6 units)
161e-10 (erg/cm2/s)
For 100 sec
3 arcmin5-band
simultaneous
photometryPrimary 300 mm
Items
Parameters
Telescope type
Offset Optics
Aperture size
30 cm
Focal length
183.5 cm
F number
F6.1
Field of view
15 arcmin × 15 arcmin
FoV per pixel
2 acsec × 2 arcsec
Image size
3 pixel × 3 pixel
Integration time
10 minutes (2 minutes x 5 frames)
Observation
0.5−0.9 0.9−1.3 1.3−1.7 1.7−2.1 2.1-2.5
Band (μm)
Limiting
21.0
20.6
20.3
20.2
20.1
Magnitude mag (AB)Focal detector
HyViSiHgCdTe (H1RG) 6

NIR Telescope and Kösters Prism

Primary30 cm

9/20(Wed.) V213a: Tsumura’s talk

- Dichroic mirror divide optical/NIR ray- Kösters Prism
consists of prisms and beam splitters,
divides the NIR ray into 4-band- Imaging with a single detector- We use 2-dimensional prism
Secondary- No. of NIR focal detector: 3 à 1- Field of view: 34 arcmin à 15 arcmin

NIRDichroicMirror
7

Optical7Requirement- Telescope : T < 200 K- Image sensor : T < 120 K
・ Passive cooling(No mechanical refrigerator)
・ Worst case estimationTemperature (K)Thermal Design of NIR telescope

9/20(Wed.) V214a: Haruki Fukui’s talk

Temperature of telescope chassis
144 K- 1 orbit- Winter Solstice- Around Antarctica

ΔT = 2.3 K

Temperature of radiator (K)Time (sec)angleTemperature of radiator
Radiator area : 480c m2

105 K
Installation angle (deg)8High-z Gamma-ray bursts for Unraveling the Dark Ages Mission
Mission Aim: Strong Promotion of“Time Domain” & “Multi-Messenger Astronomy”.

2030 –Key Science1: Probing the Early Universe
・ Detection of high-redshift GRBs (9 < z < 12)
・ Probing the reionization history and first metal elements
Key Science2: Progress of Gravitational Wave Astronomy
・ Localization of X-ray transient and macronova associated with GW
・ Energy transition from jet – cocoon – kilonova
Observation Strategy(1) Discovery of high-energy transient with Wide Field X-ray Monitor(2) Automatic/Comprehensive follow-up with Near Infrared Telescope(3) Sending Quasi-Realtime Alert Messages(4) Spectroscopy with Large Area Telescopes for selected events

Wide Field X-ray Monitor
Items
Energy band (keV)
Telescope type
Field of ViewSensitivity
Position accuracy

Parameters
0.5 – 4 keV
Lobster Eye Optics> 0.5 str (6 units)
1e-10 (erg/cm2/s)
For 100 sec exposure
3 arcminWide Field X-ray Monitor
・ Lobster Eye Optics
・ CMOS imaging sensor
Near Infrared Telescope
・ Offset Gregorian Optics
・ simultaneous 5-band
photometry

Near Infrared Telescope
Items
Aperture size
Field of viewIntegration timeObs. Band (μm)
Limiting mag (AB)
10 min, S/N=10Parameters
30 cm
15 arcmin × 15 arcmin
10 minutes (2 minutes x 5 frames)

0.5−0.9 0.9−1.31.3−1.7

1.7−2.1

2.1-2.5

21.0

20.3

20.2

20.1

20.6

Kanazawa University Satellite 「KOYOH Ｘ線突発天体監視速報衛星」
・ 50cm/50kg class micro satellite・ Mission payloads ( wide field X-ray imaging detector T-LEX, Gamma-ray detector KGD）
・ Selected as JAXA’s innovative satellite program・ Launch in Nov. 202310