MEGA: A Medium-Energy Gamma-ray Astronomy mission concept

Authors

P. F. Bloser, University of New Hampshire Durham
J. M. Ryan, University of New Hampshire Durham
M. L. McConnell, University of New Hampshire Durham
J. R. Macri, University of New Hampshire Durham
U. Bravar, University of New Hampshire Durham
G. Kanbach, Max Planck Institute for Extraterrestrial Physics
R. Andritschke, Max Planck Institute for Extraterrestrial Physics
M. Ajello, Max Planck Institute for Extraterrestrial Physics
A. Zoglauer, Space Sciences Laboratory at UC Berkeley
S. D. Hunter, NASA Goddard Space Flight Center
B. F. Phlips, Naval Research Laboratory
E. A. Wulf, Naval Research Laboratory
D. H. Hartmann, Clemson University
R. S. Miller, The University of Alabama in Huntsville
W. S. Paciesas, The University of Alabama in Huntsville
A. D. Zych, University of California, Los Angeles, Institute of Geophysics and Planetary Physics
R. M. Kippen, Los Alamos National Laboratory
T. Vestrand, Los Alamos National Laboratory
M. L. Cherry, Louisiana State University
T. G. Guzik, Louisiana State University
J. G. Stacy, Louisiana State University
J. P. Wefel, Louisiana State University
V. Reglero, Universitat de València
G. Di Cocco, INAF Istituto di Astrofisica Spaziale e Fisica Cosmica, Bologna
J. P. Cravens, Southwest Research Institute

Document Type

Conference Proceeding

Publication Date

12-1-2005

Abstract

The Medium Energy Gamma-ray Astronomy (MEGA) telescope concept will soon be proposed as a MIDEX mission. This mission would enable a sensitive all-sky survey of the medium-energy gamma-ray sky (0.4 - 50 MeV) and bridge the huge sensitivity gap between the COMPTEL and OSSE experiments on the Compton Gamma Ray Observatory, the SPI and IBIS instruments on INTEGRAL, and the visionary Advanced Compton Telescope (ACT) mission. The scientific goals include, among other things, compiling a much larger catalog of sources in this energy range, performing far deeper searches for supernovae, better measuring the galactic continuum and line emissions, and identifying the components of the cosmic diffuse gamma-ray emission. MEGA will accomplish these goals using a tracker made of Si strip detector (SSD) planes surrounded by a dense high-Z calorimeter. At lower photon energies (below ∼ 30 MeV), the design is sensitive to Compton interactions, with the SSD system serving as a scattering medium that also detects and measures the Compton recoil energy deposit. If the energy of the recoil electron is sufficiently high (> 2 MeV) its momentum vector can also be measured. At higher photon energies (above ∼10 MeV), the design is sensitive to pair production events, with the SSD system measuring the tracks of the electron and positron. A prototype instrument has been developed and calibrated in the laboratory and at a gamma-ray beam facility. We present calibration results from the prototype and describe the proposed satellite mission.

Publication Source (Journal or Book title)

Proceedings of SPIE - The International Society for Optical Engineering

First Page

1

Last Page

12

Recommended Citation

Bloser, P., Ryan, J., McConnell, M., Macri, J., Bravar, U., Kanbach, G., Andritschke, R., Ajello, M., Zoglauer, A., Hunter, S., Phlips, B., Wulf, E., Hartmann, D., Miller, R., Paciesas, W., Zych, A., Kippen, R., Vestrand, T., Cherry, M., Guzik, T., Stacy, J., Wefel, J., Reglero, V., Di Cocco, G., & Cravens, J. (2005). MEGA: A Medium-Energy Gamma-ray Astronomy mission concept. Proceedings of SPIE - The International Society for Optical Engineering, 5898, 1-12. https://doi.org/10.1117/12.617315