scholarly journals A combined Compton and coded-aperture telescope for medium-energy gamma-ray astrophysics

2018 ◽  
Vol 614 ◽  
pp. A93 ◽  
Author(s):  
Michelle Galloway ◽  
Andreas Zoglauer ◽  
Steven E. Boggs ◽  
Mark Amman

A future mission in medium-energy gamma-ray astrophysics would allow for many scientific advancements, such as a possible explanation for the excess positron emission from the Galactic center, a better understanding of nucleosynthesis and explosion mechanisms in Type Ia supernovae, and a look at the physical forces at play in compact objects such as black holes and neutron stars. Additionally, further observation in this energy regime would significantly extend the search parameter space for low-mass dark matter. In order to achieve these objectives, an instrument with good energy resolution, good angular resolution, and high sensitivity is required. In this paper we present the design and simulation of a Compton telescope consisting of cubic-centimeter cadmium zinc telluride detectors as absorbers behind a silicon tracker with the addition of a passive coded mask. The goal of the design was to create a very sensitive instrument that is capable of high angular resolution. The simulated telescope achieved energy resolutions of 1.68% FWHM at 511 keV and 1.11% at 1809 keV, on-axis angular resolutions in Compton mode of 2.63° FWHM at 511 keV and 1.30° FWHM at 1809 keV, and is capable of resolving sources to at least 0.2° at lower energies with the use of the coded mask. An initial assessment of the instrument in Compton-imaging mode yields an effective area of 183 cm2 at 511 keV and an anticipated all-sky sensitivity of 3.6 × 10−6 photons cm−2 s−1 for a broadened 511 keV source over a two-year observation time. Additionally, combining a coded mask with a Compton imager to improve point-source localization for positron detection has been demonstrated.

1978 ◽  
Vol 225 ◽  
pp. 591 ◽  
Author(s):  
D. A. Kniffen ◽  
D. L. Bertsch ◽  
D. J. Morris ◽  
R. A. R. Palmeira ◽  
K. R. Rao

1982 ◽  
Author(s):  
W. S. Paciesas ◽  
T. L. Cline ◽  
B. J. Teegarden ◽  
J. Tueller ◽  
P. Durouchoux ◽  
...  

2013 ◽  
Vol 9 (S303) ◽  
pp. 106-108
Author(s):  
Kazufumi Torii ◽  
Rei Enokiya ◽  
Yasuo Fukui ◽  
Hiroaki Yamamoto ◽  
Akiko Kawamura ◽  
...  

AbstractWe present the first results of the new CO J = (2 − 1) observations toward the central molecular zone (CMZ) using the NANTEN2 telescope at an angular resolution of 100″. Large area coverage of 4° × 2° in l and b and a high angular resolution of 100″ enable us to investigate detailed structures of the molecular gas in the CMZ including peculiar molecular filaments perpendicularly to the Galactic plane to b > |0.5°|. The major components of the CMZ, e.g., Sgr A, Sgr B and Sgr C cloud complexes, show high CO J = (2 − 1)/J = (1 − 0) ratios around 0.9, indicating highly excited conditions of the molecular gas, while the local foreground components show less than 0.4. The molecular filaments show the typical ratios of 0.6–0.7 indicate that they are indeed located in the Galactic center.


2013 ◽  
Vol 9 (S303) ◽  
pp. 461-463
Author(s):  
Cornelia C. Lang ◽  
James Toomey ◽  
Dominic Ludovici ◽  
Ann Mao ◽  
Mark Morris

Despite their discovery almost 30 years ago, the origin of the Galactic center nonthermal filaments (NTFs) remains poorly understood. The improved capabilities of the VLA offer a fantastic opportunity to make a multi-frequency, full spectropolarimetric study of the radio arc at high angular resolution. Observations presented here are from DnC and CnB array configuration data taken at S, C and X band (coverage between 2-12 GHz; continuum only). In addition there are also Ka and Q band (continuum and spectral line coverage) observations that are part of the study but not shown in this short proceedings. These data will allow us to make the first high angular resolution Faraday study of the Galactic center radio arc.


1993 ◽  
Vol 19 (7) ◽  
pp. 1053-1068 ◽  
Author(s):  
B S Acharya ◽  
P N Bhat ◽  
A V John ◽  
S G Khairatkar ◽  
B K Nagesh ◽  
...  

2004 ◽  
Author(s):  
James M. Ryan ◽  
Robert Andritschke ◽  
Peter F. Bloser ◽  
James P. Cravens ◽  
Michael L. Cherry ◽  
...  

2008 ◽  
Author(s):  
Andreas Zoglauer ◽  
Robert Andritschke ◽  
Steven E. Boggs ◽  
Florian Schopper ◽  
Georg Weidenspointner ◽  
...  

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