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Title: DISCOVERY OF DIFFUSE HARD X-RAY EMISSION AROUND JUPITER WITH SUZAKU

Abstract

We report the discovery of diffuse hard (1-5 keV) X-ray emission around Jupiter in a deep 160 ks Suzaku X-ray Imaging Spectrometer data. The emission is distributed over {approx}16 x 8 Jovian radius and spatially associated with the radiation belts and the Io Plasma Torus (IPT). It shows a flat power-law spectrum with a photon index of 1.4 {+-} 0.2 with the 1-5 keV X-ray luminosity of (3.3 {+-} 0.5)x10{sup 15} erg s{sup -1}. We discussed its origin and concluded that it seems to be truly diffuse, although a possibility of multiple background point sources cannot be completely rejected with a limited angular resolution. If it is diffuse, the flat continuum indicates that X-rays arise by the nonthermal electrons in the radiation belts and/or the IPT. The synchrotron and bremsstrahlung models can be rejected from the necessary electron energy and X-ray spectral shape, respectively. The inverse-Compton scattering off solar photons by ultra-relativistic (several tens MeV) electrons can explain the energy and the spectrum but the necessary electron density is {approx}>10 times larger than the value estimated from the empirical model of Jovian charge particles.

Authors:
; ;  [1];  [2];  [3];  [4];  [5]
  1. Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan)
  2. Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan)
  3. Department of Geophysics, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578 (Japan)
  4. Stanford Linear Accelerator Center, Standford University, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)
  5. Department of Physics, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda, Tokyo 101-8308 (Japan), E-mail: ezoe@phys.metro-u.ac.jp
Publication Date:
OSTI Identifier:
21301352
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 709; Journal Issue: 2; Other Information: DOI: 10.1088/2041-8205/709/2/L178; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BREMSSTRAHLUNG; COMPTON EFFECT; ELECTRON DENSITY; ELECTRONS; EMISSION; HARD X RADIATION; JUPITER PLANET; KEV RANGE 01-10; LUMINOSITY; MEV RANGE 10-100; PHOTONS; POINT SOURCES; RADIATION BELTS; RELATIVISTIC RANGE; SATELLITES; SPECTRA; SPECTROMETERS

Citation Formats

Ezoe, Y., Ishikawa, K., Ohashi, T., Miyoshi, Y., Terada, N., Uchiyama, Y., and Negoro, H. DISCOVERY OF DIFFUSE HARD X-RAY EMISSION AROUND JUPITER WITH SUZAKU. United States: N. p., 2010. Web. doi:10.1088/2041-8205/709/2/L178; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Ezoe, Y., Ishikawa, K., Ohashi, T., Miyoshi, Y., Terada, N., Uchiyama, Y., & Negoro, H. DISCOVERY OF DIFFUSE HARD X-RAY EMISSION AROUND JUPITER WITH SUZAKU. United States. doi:10.1088/2041-8205/709/2/L178; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
Ezoe, Y., Ishikawa, K., Ohashi, T., Miyoshi, Y., Terada, N., Uchiyama, Y., and Negoro, H. Mon . "DISCOVERY OF DIFFUSE HARD X-RAY EMISSION AROUND JUPITER WITH SUZAKU". United States. doi:10.1088/2041-8205/709/2/L178; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA).
@article{osti_21301352,
title = {DISCOVERY OF DIFFUSE HARD X-RAY EMISSION AROUND JUPITER WITH SUZAKU},
author = {Ezoe, Y. and Ishikawa, K. and Ohashi, T. and Miyoshi, Y. and Terada, N. and Uchiyama, Y. and Negoro, H.},
abstractNote = {We report the discovery of diffuse hard (1-5 keV) X-ray emission around Jupiter in a deep 160 ks Suzaku X-ray Imaging Spectrometer data. The emission is distributed over {approx}16 x 8 Jovian radius and spatially associated with the radiation belts and the Io Plasma Torus (IPT). It shows a flat power-law spectrum with a photon index of 1.4 {+-} 0.2 with the 1-5 keV X-ray luminosity of (3.3 {+-} 0.5)x10{sup 15} erg s{sup -1}. We discussed its origin and concluded that it seems to be truly diffuse, although a possibility of multiple background point sources cannot be completely rejected with a limited angular resolution. If it is diffuse, the flat continuum indicates that X-rays arise by the nonthermal electrons in the radiation belts and/or the IPT. The synchrotron and bremsstrahlung models can be rejected from the necessary electron energy and X-ray spectral shape, respectively. The inverse-Compton scattering off solar photons by ultra-relativistic (several tens MeV) electrons can explain the energy and the spectrum but the necessary electron density is {approx}>10 times larger than the value estimated from the empirical model of Jovian charge particles.},
doi = {10.1088/2041-8205/709/2/L178; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)},
journal = {Astrophysical Journal Letters},
number = 2,
volume = 709,
place = {United States},
year = {Mon Feb 01 00:00:00 EST 2010},
month = {Mon Feb 01 00:00:00 EST 2010}
}