scholarly journals Design and performance of Soft Gamma-ray Detector onboard the Hitomi (ASTRO-H) satellite

Author(s):  
Hiroyasu Tajima ◽  
Shin Watanabe ◽  
Yasushi Fukazawa ◽  
Roger Blandford
Author(s):  
H. Tajima ◽  
T. Kamae ◽  
G. Madejski ◽  
T. Mitani ◽  
K. Nakazawa ◽  
...  

2014 ◽  
Vol 28 ◽  
pp. 1460185
Author(s):  
◽  
ROBERT J. LAUER

The High Altitude Water Cherenkov (HAWC) Observatory is a wide field-of-view gamma-ray detector, sensitive to primary energies between 50 GeV and 100 TeV. The array is being built at an altitude of 4,100 m on the Sierra Negra volcano in Puebla, Mexico. With a duty cycle close to 100% and a daily coverage of ~ 8 sr of the sky above it, HAWC is ideally suited to detect bright transient events at TeV energies such as gamma-ray bursts or flares from active galactic nuclei. The array will provide an unbiased survey of gamma-ray sources at energies above 100 GeV and probe the origins of astrophysical photon emission at the highest energies. The modular design of HAWC made it possible to start data taking in September 2012 with a partial array. Operation continues while the number of water Cherenkov detectors is growing, which allowed a smooth transition to full scientific operation with 111 detectors in August 2013. The completion of the full array with 300 detectors is planned for the summer of 2014. In these proceedings, we will give an overview of the status and performance of the HAWC observatory and discuss observation strategies for various gamma-ray phenomena.


2005 ◽  
Vol 52 (6) ◽  
pp. 2749-2757 ◽  
Author(s):  
H. Tajima ◽  
T. Kamae ◽  
G. Madejski ◽  
T. Mitani ◽  
K. Nakazawa ◽  
...  

Author(s):  
D.M. Gingrich ◽  
L.M. Boone ◽  
D. Bramel ◽  
J. Carson ◽  
C.E. Covault ◽  
...  
Keyword(s):  

2012 ◽  
Author(s):  
Shin Watanabe ◽  
Hiroyasu Tajima ◽  
Yasushi Fukazawa ◽  
Roger Blandford ◽  
Teruaki Enoto ◽  
...  
Keyword(s):  

Geophysics ◽  
1987 ◽  
Vol 52 (11) ◽  
pp. 1535-1546 ◽  
Author(s):  
Ping Sheng ◽  
Benjamin White ◽  
Balan Nair ◽  
Sandra Kerford

The spatial resolution of gamma‐ray logs is defined by the length 𝓁 of the gamma‐ray detector. To resolve thin beds whose thickness is less than 𝓁, it is generally desirable to deconvolve the data to reduce the averaging effect of the detector. However, inherent in the deconvolution operation is an amplification of high‐frequency noise, which can be a detriment to the intended goal of increased resolution. We propose a Bayesian statistical approach to gamma‐ray log deconvolution which is based on optimization of a probability function which takes into account the statistics of gamma‐ray log measurements as well as the empirical information derived from the data. Application of this method to simulated data and to field measurements shows that it is effective in suppressing high‐frequency noise encountered in the deconvolution of gamma‐ray logs. In particular, a comparison with the least‐squares deconvolution approach indicates that the incorporation of physical and statistical information in the Bayesian optimization process results in optimal filtering of the deconvolved results.


Author(s):  
K. Smith ◽  
T. Baugher ◽  
S. Burcher ◽  
A.B. Carter ◽  
J.A. Cizewski ◽  
...  
Keyword(s):  

2018 ◽  
Vol 65 (4) ◽  
pp. 1066-1069 ◽  
Author(s):  
M. Niraula ◽  
K. Yasuda ◽  
M. Kojima ◽  
S. Kitagawa ◽  
S. Tsubota ◽  
...  

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