Related papers: The Compton Spectrometer and Imager Project for Me…

We investigate the detectability of polarized gamma-ray emission from blazar flares with the Compton Spectrometer and Imager (COSI). Using 17 years of Fermi Large Area Telescope observations, we analyze light curves for 1413 blazars and…

We are developing a Compton telescope based on high resolution Si and CdTe imaging devices in order to obtain a high sensitivity astrophysical observation in sub-MeV gamma-ray region. In this paper, recent results from the prototype Si/CdTe…

Double-sided strip high-purity germanium detectors with three-dimensional position reconstruction capability have been developed over three decades, with space-based applications in high-energy astrophysics and heliophysics. Position…

We propose a future mission concept, the MeV Astrophysical Spectroscopic Surveyor (MASS), which is a large area Compton telescope using 3D position sensitive cadmium zinc telluride (CZT) detectors optimized for emission line detection. The…

In 2016 the Compton Spectrometer and Imager (COSI) had a successful 46-day flight onboard NASA's Super Pressure Balloon platform. In this work we report measurements of the Galactic diffuse continuum emission (GDCE) observed towards the…

The signature of positron annihilation, namely the 511 keV $\gamma$-ray line, was first detected coming from the direction of the Galactic center in the 1970's, but the source of Galactic positrons still remains a puzzle. The measured flux…

A Compton camera is the most promising approach for gamma-ray detection in the energy region from several hundred keV to MeV, especially for application in high energy astrophysics. In order to obtain good angular resolution, semiconductor…

An advanced Compton telescope appears to be the best instrument concept for the next generation gamma-ray space observatory in the MeV range. A first prototype of advanced Compton telescope is being developed to match the constraints of a…

Photon imaging for MeV gammas has serious difficulties due to huge backgrounds and unclearness in images, which are originated from incompleteness in determining the physical parameters of Compton scattering in detection, e.g., lack of the…

Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat has been a prolific Gamma-Ray Burst (GRB) monitor. While the 2-pixel Compton scattered events (100 - 300 keV) are used to extract sensitive spectroscopic information, the inclusion of…

A future mission in medium-energy gamma-ray astrophysics would allow for many scientific advancements, e.g. a possible explanation for the excess positron emission from the Galactic Center, a better understanding of nucleosynthesis and…

Compton telescopes based on semiconductor technologies are being developed to explore the gamma-ray universe in an energy band 0.1--20 MeV, which is not well covered by the present or near-future gamma-ray telescopes. The key feature of…

We have been developing a semiconductor Compton telescope to explore the universe in the energy band from several tens of keV to a few MeV. We use a Si strip and CdTe pixel detector for the Compton telescope to cover an energy range from 60…

The Cadmium Zinc Telluride Imager (CZTI) onboard AstroSat is designed for hard X-ray imaging and spectroscopy in the energy range of 20 - 100 keV. The CZT detectors are of 5 mm thickness and hence have good efficiency for Compton…

X-ray and gamma-ray polarimetry is a promising tool to study the geometry and the magnetic configuration of various celestial objects, such as binary black holes or gamma-ray bursts (GRBs). However, statistically significant polarizations…

The goal of the Medium Energy Gamma-ray Astronomy (MEGA) telescope is to improve sensitivity at medium gamma-ray energies (0.4-50 MeV) by at least an order of magnitude over that of COMPTEL. This will be achieved with a new compact design…

A sensitive survey of the MeV gamma-ray sky is needed to understand important astrophysical problems such as gamma-ray bursts in the early universe, progenitors of Type Ia supernovae, and the nature of dark matter. However, the study has…

The sky at MeV energies is currently poorly explored. Here we present an innovative mission concept that builds on and improves past and currently proposed missions at such energies. We outline the motivations for combining a coded mask and…

Detecting gamma-ray signals that could be due to dark matter (DM) particles would give us invaluable information about the nature of DM. In particular, gamma-ray lines could provide a way to measure the DM mass. The excellent energy…

Compton telescope is a promising technology to achieve very high sensitivity in the soft gamma-ray band (0.1-10 MeV) by utilizing Compton kinematics. Compton kinematics also enables polarization measurement which will open new windows to…