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Charge Response Simulation of Liquid Argon Compton Cameras for Precise MeV Gamma-Ray Event Reconstruction
Shota Arai, Hirokazu Odaka, Satoshi Takashima +5
We studied the detector response for a liquid-argon time-projection chamber (LArTPC) Compton camera targeting MeV gamma-ray astronomy by a Geant4-based Monte Carlo simulation. The…
Low-Noise SiPM Light Readout and ASIC-Based Charge Readout of a Liquid Argon Time Projection Chamber for MeV Gamma-Ray Measurements
Satoshi Takashima, Hirokazu Odaka, Shota Arai +25
We have developed a compact liquid argon time projection chamber (LArTPC), NanoGRAMS, as a technology demonstrator for the Gamma-Ray and AntiMatter Survey (GRAMS). LArTPCs have the…
Long-term performance of SiPMs in space environment measured by GRBAlpha, GRBBeta, and VZLUSAT-2 CubeSats
Jakub Ripa, Filip Munz, Marianna Dafcikova +46
In this work, we report the successful application of silicon photomultipliers (SiPMs) in gamma-ray burst (GRB) detectors used in CubeSats operating in the low Earth orbit (LEO) ra…
In-orbit Demonstration of X-ray Pulsar Navigation with NinjaSat
Naoyuki Ota, Takuya Takahashi, Toru Tamagawa +26
This study demonstrated the pulsar navigation capability of the CubeSat X-ray observatory NinjaSat, which is equipped with two Gas Multiplier Counters (GMCs). The GMCs are sensitiv…
Pile-up simulator for XRISM/Xtend onboard the X-ray Imaging and Spectroscopy Mission (XRISM)
Tomokage Yoneyama, Tsubasa Tamba, Hirokazu Odaka +6
In X-ray astronomy, most observatories utilize multi-pixel photon-counting devices. When a photon counting device observes a bright source, we face an unavoidable problem called pi…
Development of Solar Flare X-ray Polarimeter with Micro-Pixel CMOS Sensors
Kouichi Hagino, Tatsuaki Kato, Toshiya Iwata +10
We are developing an X-ray polarimeter using micro-pixel CMOS sensors for solar flare X-ray polarimetry. The system consists of a 2.5-m pixel CMOS image sensor with a 12.8$\time…
In-orbit Performance of the Soft X-ray Imaging Telescope Xtend aboard XRISM
Hiroyuki Uchida, Koji Mori, Hiroshi Tomida +62
We present a summary of the in-orbit performance of the soft X-ray imaging telescope Xtend onboard the XRISM mission, based on in-flight observation data, including first-light cel…
Soft X-ray Imager of the Xtend system onboard XRISM
Hirofumi Noda, Koji Mori, Hiroshi Tomida +57
The Soft X-ray Imager (SXI) is the X-ray charge-coupled device (CCD) camera for the soft X-ray imaging telescope Xtend installed on the X-ray Imaging and Spectroscopy Mission (XRIS…
NinjaSat: Astronomical X-ray CubeSat Observatory
Toru Tamagawa, Teruaki Enoto, Takao Kitaguchi +22
NinjaSat is an X-ray CubeSat designed for agile, long-term continuous observations of bright X-ray sources, with the size of 6U ( mm) and a mass of 8 kg.…
Characterization of more than three years of in-orbit radiation damage of SiPMs on GRBAlpha and VZLUSAT-2 CubeSats
Jakub Ripa, Marianna Dafcikova, Pavel Kosik +42
Silicon photomultipliers (SiPMs) are prone to radiation damage which causes an increase of dark count rate. This leads to an increase in low-energy threshold in a gamma-ray detecto…
Imaging reconstruction method on X-ray data of CMOS polarimeter combined with coded aperture
Tsubasa Tamba, Hirokazu Odaka, Taihei Watanabe +7
X-ray polarization is a powerful tool for unveiling the anisotropic characteristics of high-energy celestial objects. We present a novel imaging reconstruction method designed for…
Status of Xtend telescope onboard X-Ray Imaging and Spectroscopy Mission (XRISM)
Koji Mori, Hiroshi Tomida, Hiroshi Nakajima +59
Xtend is one of the two telescopes onboard the X-ray imaging and spectroscopy mission (XRISM), which was launched on September 7th, 2023. Xtend comprises the Soft X-ray Imager (SXI…
Initial operations of the Soft X-ray Imager onboard XRISM
Hiromasa Suzuki, Tomokage Yoneyama, Shogo B. Kobayashi +52
XRISM (X-Ray Imaging and Spectroscopy Mission) is an astronomical satellite with the capability of high-resolution spectroscopy with the X-ray microcalorimeter, Resolve, and wide f…
Development of the X-ray polarimeter using CMOS imager: polarization sensitivity of a pixel CMOS sensor
Toshiya Iwata, Kouichi Hagino, Hirokazu Odaka +10
We are developing an imaging polarimeter by combining a fine-pixel CMOS image sensor with a coded aperture mask as part of the cipher project, aiming to achieve X-ray polarimetry i…
Gas selection for Xe-based LCP-GEM detectors onboard the CubeSat X-ray observatory NinjaSat
T. Takeda, T. Tamagawa, T. Enoto +18
We present a gas selection for Xe-based gas electron multiplier (GEM) detectors, Gas Multiplier Counters (GMCs) onboard the CubeSat X-ray observatory NinjaSat. To achieve an energy…
GRBAlpha: the smallest astrophysical space observatory -- Part 1: Detector design, system description and satellite operations
András Pál, Masanori Ohno, László Mészáros +42
Aims. Since launched on 2021 March 22, the 1U-sized CubeSat GRBAlpha operates and collects scientific data on high-energy transients, making it the smallest astrophysical space obs…
Early results from GRBAlpha and VZLUSAT-2
Jakub Ripa, Andras Pal, Masanori Ohno +37
We present the detector performance and early science results from GRBAlpha, a 1U CubeSat mission, which is a technological pathfinder to a future constellation of nanosatellites m…
Event reconstruction of Compton telescopes using a multi-task neural network
Satoshi Takashima, Hirokazu Odaka, Hiroki Yoneda +4
We have developed a neural network model to perform event reconstruction of Compton telescopes. This model reconstructs events that consist of three or more interactions in a detec…
Simulation-based spectral analysis of X-ray CCD data affected by photon pile-up
Tsubasa Tamba, Hirokazu Odaka, Aya Bamba +6
We have developed a simulation-based method of spectral analysis for pile-up affected data of X-ray CCDs without any loss of photon statistics. As effects of the photon pile-up app…
Reconstruction of multiple Compton scattering events in MeV gamma-ray Compton telescopes towards GRAMS: the physics-based probabilistic model
Hiroki Yoneda, Hirokazu Odaka, Yuto Ichinohe +19
Aimed at progress in mega-electron volt (MeV) gamma-ray astronomy, which has not yet been well-explored, Compton telescope missions with a variety of detector concepts have been pr…
TeV emission of Galactic plane sources with HAWC and H.E.S.S
H. Abdalla, F. Aharonian, F. Ait Benkhali +318
The High Altitude Water Cherenkov (HAWC) observatory and the High Energy Stereoscopic System (H.E.S.S.) are two leading instruments in the ground-based very-high-energy gamma-ray d…
Detailed Design of the Science Operations for the XRISM mission
Yukikatsu Terada, Matt Holland, Michael Loewenstein +36
XRISM is an X-ray astronomical mission by the JAXA, NASA, ESA and other international participants, that is planned for launch in 2022 (Japanese fiscal year), to quickly restore hi…
Simulations of expected signal and background of gamma-ray sources by large field-of-view detectors aboard CubeSats
Gábor Galgóczi, Jakub Řípa, Riccardo Campana +19
In recent years the number of CubeSats (U-class spacecrafts) launched into space has increased exponentially marking the dawn of the nanosatellite technology. In general these sate…
The simulation framework of the timing-based localization for future all-sky gamma-ray observations with a fleet of Cubesats
Masanori Ohno, Norbert Werner, Andras Pal +22
The timing-based localization, which utilize the triangulation principle with the different arrival time of gamma-ray photons, with a fleet of Cubesats is a unique and powerful sol…