Engineering topics

Kamae, T.

Publications and source records attributed to Kamae, T..

4 records

DOE OSTI2020

Fermi Large Area Telescope Fourth Source Catalog

We present the fourth Fermi Large Area Telescope catalog (4FGL) of γ-ray sources. Based on the first eight years of science data from the Fermi Gamma-ray Space Telescope mission in the energy range from 50 MeV to 1 TeV, it is the deepest yet in this energy range. Relative to the 3FGL catalog, the 4FGL catalog has twice as much exposure as well as a number of analysis improvements, including an updated model for the Galactic diffuse γ-ray emission, and two sets of light curves (one-year and two-month intervals). The 4FGL catalog includes 5064 sources above 4σ significance, for which we provide localization and spectral properties. Seventy-five sources are modeled explicitly as spatially extended, and overall, 358 sources are considered as identified based on angular extent, periodicity, or correlated variability observed at other wavelengths. For 1336 sources, we have not found plausible counterparts at other wavelengths. More than 3130 of the identified or associated sources are active galaxies of the blazar class, and 239 are pulsars.

79 ASTRONOMY AND ASTROPHYSICS↗

NASA NTRS2001

Gamma Ray Large Area Space Telescope (GLAST) Balloon Flight Engineering Model: Overview

The Gamma Ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) is a pair-production high-energy (greater than 20 MeV) gamma-ray telescope being built by an international partnership of astrophysicists and particle physicists for a satellite launch in 2006, designed to study a wide variety of high-energy astrophysical phenomena. As part of the development effort, the collaboration has built a Balloon Flight Engineering Model (BFEM) for flight on a high-altitude scientific balloon. The BFEM is approximately the size of one of the 16 GLAST-LAT towers and contains all the components of the full instrument: plastic scintillator anticoincidence system (ACD), high-Z foil/Si strip pair-conversion tracker (TKR), CsI hodoscopic calorimeter (CAL), triggering and data acquisition electronics (DAQ), commanding system, power distribution, telemetry, real-time data display, and ground data processing system. The principal goal of the balloon flight was to demonstrate the performance of this instrument configuration under conditions similar to those expected in orbit. Results from a balloon flight from Palestine, Texas, on August 4, 2001, show that the BFEM successfully obtained gamma-ray data in this high-background environment.

Thompson, D. J.↗

NASA NTRS1998

Studying the High Energy Gamma Ray Sky with Gamma Ray Large Area Space Telescope (GLAST)

Building on the success of the Energetic Gamma Ray Experiment Telescope (EGRET) on the Compton Gamma Ray Observatory, the Gamma Ray Large Area Space Telescope (GLAST) will make a major step in the study of such subjects as blazars, gamma Ray bursts, the search for dark matter, supernova remnants, pulsars, diffuse radiation, and unidentified high energy sources. The instrument will be built on new and mature detector technologies such as silicon strip detectors, low-power low-noise LSI, and a multilevel data acquisition system. GLAST is in the research and development phase, and one full tower (of 25 total) is now being built in collaborating institutes. The prototype tower will be tested thoroughly at Stanford Linear Accelerator Center (SLAC) in the fall of 1999.

Kamae, T.↗

NASA NTRS1996

Observations of blazars with ASCA

The Advanced Satellite for Cosmology and Astrophysics (ASCA) observations of 3C 279, Mkn 421, PKS 2155-304, BL Lac 0716+714 and OJ 287 blazars are presented. Blazars are a class of active galactic nuclei characterized by high variability, high polarization, flat radio spectrum and featureless spectrum. The X-ray spectra and flux variations of blazars are discussed. The inverse correlation between X-ray flux and index, soft lag, the convex curvature of the spectrum, flat gamma-ray and/or X-ray spectra, fast variability and featureless spectrum are common characteristics of blazars.

Makino, F.↗