Assuming that each subjet follows the Yonetoku relation, i.e., E rest p ∝ L 1/2 p , we performed Monte Carlo simulations in the context of a multiple subjet model (or inhomogeneous jet model) for gamma-ray bursts (GRBs), X-ray–rich GRBs (XRRs), and X-ray flashes (XRFs). For a single subjet, we found that E rest p ∝ Eiso 0.4 for large viewing angle. For the multiple subjet model under the univer...

We investigate hypernova (hyper-energetic supernova) and gamma-ray burst (GRB) remnants in our Galaxy as TeV gamma-ray sources, particularly in the role of potential TeV unidentified sources, which have no clear counterpart at other wavelengths. We show that the observed bright sources in the TeV sky could be dominated by GRB/hypernova remnants, even though they are fewer than supernova remnant...

We show that some types of variabilities of gamma-ray burst (GRB) afterglows are forbidden by simple kinematical arguments. These limits help us to identify the source of afterglow variabilities. Actually the afterglows of GRB 011211 and GRB 021004 violate these limits, implying that the compact object that powers GRB jets may continue to eject an intermittent outflow for a very long timescale ...

We are developing a new type of photon detector in preparation of an experiment to search for muons decaying into positrons and gamma rays. In the experiment, the photon detector will utilize liquid xenon (Xe) as the scintillation material because of its fast response, large light yield, and high density. The scintillation light emitted in liquid Xe will be observed directly by positioning phot...

The gamma-ray imaging spectrometer (GRIS) we have assembled comprises four coaligned, independent imagers, each with its own detector and coded-aperture mask (Figure 1). Each detector “sees” incoming gamma rays only through its mask, which serves as the imaging optic for the gamma rays (see box, pp. 1819). This mask is mounted on a movable mask plate in front of the detector plane; moving the p...

We present recipes to diagnose the fireball of gamma-ray bursts (GRBs) by combining observations of e pair-signatures (the pair-annihilation line and the cutoff energy due to the pair-creation process). Our recipes are largely model-independent and extract information even from the non-detection of either pair-signature. We evaluate physical quantities such as the Lorentz factor, optical depth ...

UNLABELLED Planar gamma-scintigraphy is often used to quantify pulmonary deposition patterns from aerosol inhalers. The results are quite different from those obtained using 3-dimensional PET and SPECT. The purpose of this study was to characterize the effects of scatter and tissue attenuation on the distribution of radiolabeled aerosol as measured by planar scintigraphy using Monte Carlo simul...

We developed a positron emission tomography (PET) system for multiple-isotope imaging. Our PET system, named (MI-PET), can distinguish between different tracer nuclides using coincidence measurement of prompt gamma-rays, which are emitted after emission. In MI-PET imaging with pure emitter and prompt-gamma emitter, because the imperfectness gamma-ray detection, an image taken by is superposed p...

• Automatic Functions: Exposure, White Balance, Black Level Offset Correction, Flicker Detection and Avoidance, Color Saturation Control, Defect Identification and Correction, Aperture Correction, and GPIO • Programmable Controls: Exposure, White Balance, Horizontal and Vertical Blanking, Color, Sharpness, Gamma, Lens Shading Correction, Horizontal and Vertical Image Flip, Zoom, Windowing, Samp...