152 citations · 1.6k across the 86 of their papers we have counts for
21 papers · 1 filter
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…
Broad-band High-Energy Resolution Hard X-ray Spectroscopy using Transition Edge Sensors at SPring-8
Shinya Yamada, Yuto Ichinohe, Hideyuki Tatsuno +40
We have succeeded in operating a transition-edge sensor (TES) spectrometer and evaluating its performance at the SPring-8 synchrotron X-ray light source. The TES spectrometer consi…
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…
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…
Application of deep learning to the evaluation of goodness in the waveform processing of transition-edge sensor calorimeters
Y. Ichinohe, S. Yamada, R. Hayakawa +5
Optimal filtering is the crucial technique for the data analysis of transition-edge-sensor (TES) calorimeters to achieve their state-of-the-art energy resolutions. Filtering out th…
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…
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…
GRBAlpha: A 1U CubeSat mission for validating timing-based gamma-ray burst localization
András Pál, Masanori Ohno, László Mészáros +26
GRBAlpha is a 1U CubeSat mission with an expected launch date in the first half of 2021. It carries a 75 x 75 x 5 mm CsI(Tl) scintillator, read out by a dual-channel multi-pixel ph…
X-ray Study of Spatial Structures in Tycho's Supernova Remnant Using Unsupervised Deep Learning
Hiroyoshi Iwasaki, Yuto Ichinohe, Yasunobu Uchiyama
Recent rapid development of deep learning algorithms, which can implicitly capture structures in high-dimensional data, opens a new chapter in astronomical data analysis. We report…
Neural network-based anomaly detection for high-resolution X-ray spectroscopy
Y. Ichinohe, S. Yamada
We propose an anomaly detection technique for high-resolution X-ray spectroscopy. The method is based on the neural network architecture variational autoencoder, and requires only…
CAMELOT: design and performance verification of the detector concept and localization capability
Masanori Ohno, Norbert Werner, András Pál +16
A fleet of nanosatellites using precise timing synchronization provided by the Global Positioning System is a new concept for monitoring the gamma-ray sky that can achieve both all…
CAMELOT - Concept study and early results for onboard data processing and GPS-based timestamping
András Pál, László Mészáros, Norbert Tarcai +17
Due to recent advances in nanosatellite technology, it is now feasible to integrate scintillators with an effective area of hundreds of square-centimeters on a single three-unit cu…
CAMELOT: Cubesats Applied for MEasuring and LOcalising Transients - Mission Overview
Norbert Werner, Jakub Řípa, András Pál +17
We propose a fleet of nanosatellites to perform an all-sky monitoring and timing based localisation of gamma-ray transients. The fleet of at least nine 3U cubesats shall be equippe…
Imaging and spectral performance of CdTe double-sided strip detectors for the Hard X-ray Imager onboard ASTRO-H
Kouichi Hagino, Hirokazu Odaka, Goro Sato +20
The imaging and spectral performance of CdTe double-sided strip detectors (CdTe-DSDs) was evaluated for the ASTRO-H mission. The charcterized CdTe-DSDs have a strip pitch of 0.25 m…
Neural network-based preprocessing to estimate the parameters of the X-ray emission of a single-temperature thermal plasma
Y. Ichinohe, S. Yamada, N. Miyazaki +1
We present data preprocessing based on an artificial neural network to estimate the parameters of the X-ray emission spectra of a single-temperature thermal plasma. The method find…
Study of the Polarimetric Performance of a Si/CdTe Semiconductor Compton Camera for the Hitomi Satellite
Junichiro Katsuta, Ikumi Edahiro, Shin Watanabe +17
Gamma-ray polarization offers a unique probes into the geometry of the gamma-ray emission process in celestial objects. The Soft Gamma-ray Detector (SGD) onboard the X-ray observat…
The first demonstration of the concept of "narrow-FOV Si/CdTe semiconductor Compton camera"
Yuto Ichinohe, Yuusuke Uchida, Shin Watanabe +14
The Soft Gamma-ray Detector (SGD), to be deployed onboard the {\it ASTRO-H} satellite, has been developed to provide the highest sensitivity observations of celestial sources in th…
The Si/CdTe semiconductor Compton camera of the ASTRO-H Soft Gamma-ray Detector (SGD)
Shin Watanabe, Hiroyasu Tajima, Yasushi Fukazawa +23
The Soft Gamma-ray Detector (SGD) is one of the instrument payloads onboard ASTRO-H, and will cover a wide energy band (60--600 keV) at a background level 10 times better than inst…