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Title: Extreme Blazars Studied With Fermi -Lat And Suzaku : 1es 0347–121 And Blazar Candidate Hess J1943+213

We report on our study of high-energy properties of two peculiar TeV emitters: the “extreme blazar" 1ES 0347-121 and the “extreme blazar candidate" HESS J1943+213 located near the Galactic Plane. Both objects are characterized by quiescent synchrotron emission with flat spectra extending up to the hard X-ray range, and both were reported to be missing GeV counterparts in the Fermi-LAT 2–year Source Catalog. We analyze a 4.5 year accumulation of the Fermi-LAT data, resulting in the detection of 1ES 0347-121 in the GeV band, as well as in improved upper limits for HESS J1943+213. We also present the analysis results of newly acquired Suzaku data for HESS J1943+213. The X-ray spectrum is well represented by a single power law extending up to 25 keV with photon index 2.00±0.02 and a moderate absorption in excess of the Galactic value, in agreementwith previous X-ray observations. No short-term X-ray variability was found over the 80 ks duration of the Suzaku exposure. Under the blazar hypothesis, we modeled the spectral energy distributions of 1ES 0347-121 and HESS J1943+213, and derived constraints on the intergalactic magnetic field strength and source energetics. We conclude that although the classification of HESS J1943+213 has not yet been determined,more » the blazar hypothesis remains the most plausible option, since in particular the broad-band spectra of the two analyzed sources along with the source model parameters closely resemble each other, and the newly available WISE and UKIDSS data for HESS J1943+213 are consistent with the presence of an elliptical host at the distance of approximatel ~ 600Mpc.« less
Authors:
 [1] ;  [2] ;  [3] ;  [3] ; ORCiD logo [3] ;  [4] ;  [5] ; ORCiD logo [6] ;  [7] ;  [8] ;  [1] ;  [9]
  1. Hiroshima Univ. (Japan)
  2. Japan Aerospace Exploration Agency, Kanagawa (Japan). Inst. of Space and Astronautical Science; Jagiellonian Univ., Krakow (Poland)
  3. Naval Research Lab. (NRL), Washington, DC (United States)
  4. Waseda Univ., Shinjuku (Japan)
  5. Aoyama Gakuin Univ., Tokyo (Japan)
  6. Inst. de Planetologie et d'Astrophysique de Grenoble (France)
  7. Ecole Polytechnique, Palaiseau (France)
  8. Univ. of Heidelberg (Germany)
  9. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
Publication Date:
Grant/Contract Number:
AC02-76SF00515
Type:
Accepted Manuscript
Journal Name:
Astrophysical Journal
Additional Journal Information:
Journal Volume: 787; Journal Issue: 2; Journal ID: ISSN 0004-637X
Publisher:
Institute of Physics (IOP)
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS
OSTI Identifier:
1356469

Tanaka, Y. T., Stawarz, Ł., Finke, J., Cheung, C. C., Dermer, C. D., Kataoka, J., Bamba, A., Dubus, G., De Naurois, M., Wagner, S. J., Fukazawa, Y., and Thompson, D. J.. Extreme Blazars Studied With Fermi -Lat And Suzaku : 1es 0347–121 And Blazar Candidate Hess J1943+213. United States: N. p., Web. doi:10.1088/0004-637X/787/2/155.
Tanaka, Y. T., Stawarz, Ł., Finke, J., Cheung, C. C., Dermer, C. D., Kataoka, J., Bamba, A., Dubus, G., De Naurois, M., Wagner, S. J., Fukazawa, Y., & Thompson, D. J.. Extreme Blazars Studied With Fermi -Lat And Suzaku : 1es 0347–121 And Blazar Candidate Hess J1943+213. United States. doi:10.1088/0004-637X/787/2/155.
Tanaka, Y. T., Stawarz, Ł., Finke, J., Cheung, C. C., Dermer, C. D., Kataoka, J., Bamba, A., Dubus, G., De Naurois, M., Wagner, S. J., Fukazawa, Y., and Thompson, D. J.. 2014. "Extreme Blazars Studied With Fermi -Lat And Suzaku : 1es 0347–121 And Blazar Candidate Hess J1943+213". United States. doi:10.1088/0004-637X/787/2/155. https://www.osti.gov/servlets/purl/1356469.
@article{osti_1356469,
title = {Extreme Blazars Studied With Fermi -Lat And Suzaku : 1es 0347–121 And Blazar Candidate Hess J1943+213},
author = {Tanaka, Y. T. and Stawarz, Ł. and Finke, J. and Cheung, C. C. and Dermer, C. D. and Kataoka, J. and Bamba, A. and Dubus, G. and De Naurois, M. and Wagner, S. J. and Fukazawa, Y. and Thompson, D. J.},
abstractNote = {We report on our study of high-energy properties of two peculiar TeV emitters: the “extreme blazar" 1ES 0347-121 and the “extreme blazar candidate" HESS J1943+213 located near the Galactic Plane. Both objects are characterized by quiescent synchrotron emission with flat spectra extending up to the hard X-ray range, and both were reported to be missing GeV counterparts in the Fermi-LAT 2–year Source Catalog. We analyze a 4.5 year accumulation of the Fermi-LAT data, resulting in the detection of 1ES 0347-121 in the GeV band, as well as in improved upper limits for HESS J1943+213. We also present the analysis results of newly acquired Suzaku data for HESS J1943+213. The X-ray spectrum is well represented by a single power law extending up to 25 keV with photon index 2.00±0.02 and a moderate absorption in excess of the Galactic value, in agreementwith previous X-ray observations. No short-term X-ray variability was found over the 80 ks duration of the Suzaku exposure. Under the blazar hypothesis, we modeled the spectral energy distributions of 1ES 0347-121 and HESS J1943+213, and derived constraints on the intergalactic magnetic field strength and source energetics. We conclude that although the classification of HESS J1943+213 has not yet been determined, the blazar hypothesis remains the most plausible option, since in particular the broad-band spectra of the two analyzed sources along with the source model parameters closely resemble each other, and the newly available WISE and UKIDSS data for HESS J1943+213 are consistent with the presence of an elliptical host at the distance of approximatel ~ 600Mpc.},
doi = {10.1088/0004-637X/787/2/155},
journal = {Astrophysical Journal},
number = 2,
volume = 787,
place = {United States},
year = {2014},
month = {5}
}