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Title: Synchrotron self-inverse Compton radiation from reverse shock on GRB 120326A

We present multi-wavelength observations of a typical long duration GRB 120326A at z = 1.798, including rapid observations using a Submillimeter Array (SMA) and a comprehensive monitoring in the X-ray and optical. The SMA observation provided the fastest detection to date among seven submillimeter afterglows at 230 GHz. The prompt spectral analysis, using Swift and Suzaku, yielded a spectral peak energy of E{sub peak}{sup src}=107.8{sub −15.3}{sup +15.3} keV and an equivalent isotropic energy of E{sub iso} as 3.18{sub −0.32}{sup +0.40}×10{sup 52} erg. The temporal evolution and spectral properties in the optical were consistent with the standard forward shock synchrotron with jet collimation (6.°69 ± 0.°16). The forward shock modeling, using a two-dimensional relativistic hydrodynamic jet simulation, was also determined by the reasonable burst explosion and the synchrotron radiation parameters for the optical afterglow. The X-ray light curve showed no apparent jet break and the temporal decay index relation between the X-ray and optical (αo – α{sub X} = –1.45 ± 0.10) indicated different radiation processes in each of them. Introducing synchrotron self-inverse Compton radiation from reverse shock is a possible solution, and the detection and slow decay of the afterglow in submillimeter supports that this is a plausible idea. Themore » observed temporal evolution and spectral properties, as well as forward shock modeling parameters, enabled us to determine reasonable functions to describe the afterglow properties. Because half of the events share similar properties in the X-ray and optical as the current event, GRB 120326A will be a benchmark with further rapid follow-ups, using submillimeter instruments such as an SMA and the Atacama Large Millimeter/submillimeter Array.« less
Authors:
 [1] ; ;  [2] ; ; ;  [3] ;  [4] ;  [5] ;  [6]
  1. Institute of Astronomy, National Central University, Chung-Li 32054, Taiwan (China)
  2. Academia Sinica Institute of Astronomy and Astrophysics, Taipei 106, Taiwan (China)
  3. Center for the Exploration of the Origin of the Universe, Department of Physics and Astronomy, FPRD, Seoul National University, Shillim-dong, San 56-1, Kwanak-gu, Seoul (Korea, Republic of)
  4. Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan)
  5. Department of Physics, Saitama University, Shimo-Okubo, Saitama 338-8570 (Japan)
  6. School of Space Research, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22365682
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 789; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AFTERGLOW; BENCHMARKS; COSMIC GAMMA BURSTS; DECAY; DETECTION; EXPLOSIONS; GHZ RANGE; KEV RANGE; RELATIVISTIC RANGE; SIMULATION; SYNCHROTRON RADIATION; TWO-DIMENSIONAL CALCULATIONS; VISIBLE RADIATION; WAVELENGTHS; X RADIATION