Related papers: Data Analysis for a Balloon Borne Compton Polarime…
The Gamma-Ray Imager/Polarimeter for Solar flares (GRIPS) is a balloon-borne telescope designed to study solar-flare particle acceleration and transport. We describe GRIPS's first Antarctic long-duration flight in Jan 2016 and report…
XL-Calibur is a balloon-borne Compton polarimeter for X-rays in the $\sim$15-80 keV range. Using an X-ray mirror with a 12 m focal length for collecting photons onto a beryllium scattering rod surrounded by CZT detectors, a…
We investigate polarization of high-energy emissions from the Crab pulsar in the frame work of the outer gap accelerator. The recent version of the outer gap, which extends from inside the null charge surface to the light cylinder, is used…
The paper presents the timing and spectral analysis of several observations of the Crab pulsar performed with INTEGRAL in the energy range 3-500 keV. All these observations, when summed together provide a high statistics data set which can…
We report on the design and estimated performance of a balloon-borne hard X-ray polarimeter called HX-POL. The experiment uses a combination of Si and Cadmium Zinc Telluride detectors to measure the polarization of 50 keV-400 keV X-rays…
The ``Gamma Ray Astronomy at ALmeria'' (GRAAL) experiment uses 63 heliostat-mirrors with a total mirror area of ~ 2500 m2 from the CESA-1 field to collect Cherenkov light from airshowers. The detector is located in a central solar tower and…
Compton scattering by the proton has been measured over a wide range covering photon energies 250 MeV < E_\gamma < 800 MeV and photon scattering angles 30^0 < \theta^{lab}_\gamma < 150^0, using the tagged-photon facility at MAMI (Mainz) and…
To achieve confident non-zero polarization measurements for gamma-ray bursts (GRBs) we need sensitive polarimeters and bright GRBs. Here we report on the polarimetric analysis of the bright GRB 180720B using the \Fermi Gamma-ray Burst…
In separate series of observations of the Crab pulsar, pulse broadening due to scattering was measured at 111 MHz, and variations of dispersion due to pulse delay were measured at higher radio frequencies. In a remarkable event lasting 200…
Positron Emission Tomography (PET) is a medical imaging modality that utilizes positron-emitting isotopes, such as Ga-68 and F-18, for many diagnostic purposes. The positron annihilates with an electron from the surrounding area, creating…
MeV gamma-rays provide a unique window for the direct measurement of line emissions from radioisotopes, but observations have made little significant progress after COMPTEL/{\it CGRO}. To observe celestial objects in this band, we are…
A sounding-rocket program called the Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) is proposed to be launched in the summer of 2014. CLASP will observe the solar chromosphere in Ly-alpha (121.567 nm), aiming to detect the linear…
We report on observations of the Cosmic Microwave Background (CMB) obtained during the January 2003 flight of Boomerang . These results are derived from 195 hours of observation with four 145 GHz Polarization Sensitive Bolometer (PSB)…
To constrain the giant pulse (GP) emission mechanism and test the model of Lyutikov (2007) of GP emission, we are carrying out a campaign of simultaneous observations of the Crab pulsar between gamma-rays (Fermi) and radio wavelengths. The…
POLAR-2, a plastic scintillator based Compton polarimeter, is currently under development and planned for a launch to the China Space Station in 2025. It is intended to shed a new light on our understanding of Gamma-Ray Bursts by performing…
Period estimation is an important task in the classification of many variable astrophysical objects. Here we present GRAPE: Genetic Routine for Astronomical Period Estimation, a genetic algorithm optimised for the processing of survey data…
The linear polarisation fraction and angle of the hard X-ray emission from the Crab provide unique insight into high energy radiation mechanisms, complementing the usual imaging, timing and spectroscopic approaches. Results have recently…
We present a phase-dependent analysis of the polarized emission from the Crab pulsar based on three sets of observations by the Imaging X-ray Polarimetry Explorer (IXPE). We found that a phenomenological model involving a simple linear…
In the first half year of operation the satellite borne POLAR instrument detected a total of 55 Gamma-Ray Bursts about 10 of which were bright enough to allow for detailed polarization studies, thereby forming the start of the first…
Aims. The Crab nebula displayed a large gamma-ray flare on September 18, 2010. To more closely understand the origin of this phenomenon, we analyze the INTEGRAL (20-500 keV) and FERMI (0.1-300 GeV) data collected almost simultaneously…