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Title: Imaging Polarimeter for a Sub-MeV Gamma-Ray All-sky Survey Using an Electron-tracking Compton Camera

Abstract

X-ray and gamma-ray polarimetry is a promising tool to study the geometry and the magnetic configuration of various celestial objects, such as binary black holes or gamma-ray bursts (GRBs). However, statistically significant polarizations have been detected in few of the brightest objects. Even though future polarimeters using X-ray telescopes are expected to observe weak persistent sources, there are no effective approaches to survey transient and serendipitous sources with a wide field of view (FoV). Here we present an electron-tracking Compton camera (ETCC) as a highly sensitive gamma-ray imaging polarimeter. The ETCC provides powerful background rejection and a high modulation factor over an FoV of up to 2 π sr thanks to its excellent imaging based on a well-defined point-spread function. Importantly, we demonstrated for the first time the stability of the modulation factor under realistic conditions of off-axis incidence and huge backgrounds using the SPring-8 polarized X-ray beam. The measured modulation factor of the ETCC was 0.65 ± 0.01 at 150 keV for an off-axis incidence with an oblique angle of 30° and was not degraded compared to the 0.58 ± 0.02 at 130 keV for on-axis incidence. These measured results are consistent with the simulation results. Consequently, we foundmore » that the satellite-ETCC proposed in Tanimori et al. would provide all-sky surveys of weak persistent sources of 13 mCrab with 10% polarization for a 10{sup 7} s exposure and over 20 GRBs down to a 6 × 10{sup −6} erg cm{sup −2} fluence and 10% polarization during a one-year observation.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;  [1];  [2];  [3];  [4]
  1. Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502 (Japan)
  2. New Industry Creation Hatchery Center (NICHe), Tohoku University, Sendai, Miyagi, 980-8579 (Japan)
  3. Department of Physics, Kobe University, Kobe, Hyogo, 658-8501 (Japan)
  4. College of Science and Engineering, School of Mathematics and Physics, Kanazawa University, Kanazawa, Ishikawa, 920-1192 (Japan)
Publication Date:
OSTI Identifier:
22661146
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 839; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BEAMS; BLACK HOLES; CONFIGURATION; COSMIC GAMMA BURSTS; ELECTRONS; GAMMA RADIATION; KEV RANGE; MEV RANGE; MODULATION; POLARIMETERS; POLARIMETRY; POLARIZATION; SATELLITES; SIMULATION; SPRING-8 STORAGE RING; STABILITY; TELESCOPES; X RADIATION

Citation Formats

Komura, S., Takada, A., Mizumura, Y., Miyamoto, S., Takemura, T., Kishimoto, T., Kubo, H., Matsuoka, Y., Mizumoto, T., Nakamasu, Y., Nakamura, K., Oda, M., Parker, J. D., Sonoda, S., Tanimori, T., Tomono, D., Yoshikawa, K., Kurosawa, S., Miuchi, K., and Sawano, T., E-mail: komura@cr.scphys.kyoto-u.ac.jp. Imaging Polarimeter for a Sub-MeV Gamma-Ray All-sky Survey Using an Electron-tracking Compton Camera. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA68DC.
Komura, S., Takada, A., Mizumura, Y., Miyamoto, S., Takemura, T., Kishimoto, T., Kubo, H., Matsuoka, Y., Mizumoto, T., Nakamasu, Y., Nakamura, K., Oda, M., Parker, J. D., Sonoda, S., Tanimori, T., Tomono, D., Yoshikawa, K., Kurosawa, S., Miuchi, K., & Sawano, T., E-mail: komura@cr.scphys.kyoto-u.ac.jp. Imaging Polarimeter for a Sub-MeV Gamma-Ray All-sky Survey Using an Electron-tracking Compton Camera. United States. doi:10.3847/1538-4357/AA68DC.
Komura, S., Takada, A., Mizumura, Y., Miyamoto, S., Takemura, T., Kishimoto, T., Kubo, H., Matsuoka, Y., Mizumoto, T., Nakamasu, Y., Nakamura, K., Oda, M., Parker, J. D., Sonoda, S., Tanimori, T., Tomono, D., Yoshikawa, K., Kurosawa, S., Miuchi, K., and Sawano, T., E-mail: komura@cr.scphys.kyoto-u.ac.jp. Mon . "Imaging Polarimeter for a Sub-MeV Gamma-Ray All-sky Survey Using an Electron-tracking Compton Camera". United States. doi:10.3847/1538-4357/AA68DC.
@article{osti_22661146,
title = {Imaging Polarimeter for a Sub-MeV Gamma-Ray All-sky Survey Using an Electron-tracking Compton Camera},
author = {Komura, S. and Takada, A. and Mizumura, Y. and Miyamoto, S. and Takemura, T. and Kishimoto, T. and Kubo, H. and Matsuoka, Y. and Mizumoto, T. and Nakamasu, Y. and Nakamura, K. and Oda, M. and Parker, J. D. and Sonoda, S. and Tanimori, T. and Tomono, D. and Yoshikawa, K. and Kurosawa, S. and Miuchi, K. and Sawano, T., E-mail: komura@cr.scphys.kyoto-u.ac.jp},
abstractNote = {X-ray and gamma-ray polarimetry is a promising tool to study the geometry and the magnetic configuration of various celestial objects, such as binary black holes or gamma-ray bursts (GRBs). However, statistically significant polarizations have been detected in few of the brightest objects. Even though future polarimeters using X-ray telescopes are expected to observe weak persistent sources, there are no effective approaches to survey transient and serendipitous sources with a wide field of view (FoV). Here we present an electron-tracking Compton camera (ETCC) as a highly sensitive gamma-ray imaging polarimeter. The ETCC provides powerful background rejection and a high modulation factor over an FoV of up to 2 π sr thanks to its excellent imaging based on a well-defined point-spread function. Importantly, we demonstrated for the first time the stability of the modulation factor under realistic conditions of off-axis incidence and huge backgrounds using the SPring-8 polarized X-ray beam. The measured modulation factor of the ETCC was 0.65 ± 0.01 at 150 keV for an off-axis incidence with an oblique angle of 30° and was not degraded compared to the 0.58 ± 0.02 at 130 keV for on-axis incidence. These measured results are consistent with the simulation results. Consequently, we found that the satellite-ETCC proposed in Tanimori et al. would provide all-sky surveys of weak persistent sources of 13 mCrab with 10% polarization for a 10{sup 7} s exposure and over 20 GRBs down to a 6 × 10{sup −6} erg cm{sup −2} fluence and 10% polarization during a one-year observation.},
doi = {10.3847/1538-4357/AA68DC},
journal = {Astrophysical Journal},
number = 1,
volume = 839,
place = {United States},
year = {Mon Apr 10 00:00:00 EDT 2017},
month = {Mon Apr 10 00:00:00 EDT 2017}
}