Suzaku observation of the tev blazar íes 1218+304: clues on particle acceleration in an extreme tev blazar

R. Sato, Jun Kataoka, T. Takahashi, G. M. Madejski, S. Rügamer, S. J. Wagner

Research output: Contribution to journalArticle

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Abstract

We observed the TeV blazar IES 1218+304 with the X-ray astronomy satellite Suzaku in 2006 May. At the beginning of the 2 day continuous observation, we detected a large flare in which the 5-10 keV flux changed by a factor of ∼2 on a timescale of 5 × 104 s. During the flare, the increase in the hard X-ray flux clearly lagged behind that observed in the soft X-rays, with the maximum lag of 2.3 × 104 s observed between the 0.3-1 keV and 5-10 keV bands. Furthermore, we discovered that the temporal profile of the flare clearly changes with energy, being more symmetric at higher energies. From the spectral fitting of multiwavelength data assuming a one-zone, homogeneous synchrotron self-Compton model, we obtain a magnetic field strength B ~ 0.047 G and an emission region size R = 3.0 × 1016 cm for an appropriate beaming with a Doppler factor of δ = 20. This value of B is in good agreement with an independent estimate through the model fit to the observed time lag ascribing the energy-dependent variability to the differential acceleration timescale of relativistic electrons provided that the gyrofactor ξ is 105.

Original languageEnglish
JournalAstrophysical Journal
Volume680
Issue number1 PART 2
DOIs
Publication statusPublished - 2008
Externally publishedYes

Fingerprint

particle acceleration
flares
time lag
timescale
energy
x rays
astronomy
field strength
synchrotrons
magnetic field
electron
estimates
profiles
magnetic fields
particle
electrons

Keywords

  • Radiation mechanisms: Nonthermal
  • Rays: Galaxies
  • X-

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Suzaku observation of the tev blazar íes 1218+304 : clues on particle acceleration in an extreme tev blazar. / Sato, R.; Kataoka, Jun; Takahashi, T.; Madejski, G. M.; Rügamer, S.; Wagner, S. J.

In: Astrophysical Journal, Vol. 680, No. 1 PART 2, 2008.

Research output: Contribution to journalArticle

Sato, R. ; Kataoka, Jun ; Takahashi, T. ; Madejski, G. M. ; Rügamer, S. ; Wagner, S. J. / Suzaku observation of the tev blazar íes 1218+304 : clues on particle acceleration in an extreme tev blazar. In: Astrophysical Journal. 2008 ; Vol. 680, No. 1 PART 2.
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AB - We observed the TeV blazar IES 1218+304 with the X-ray astronomy satellite Suzaku in 2006 May. At the beginning of the 2 day continuous observation, we detected a large flare in which the 5-10 keV flux changed by a factor of ∼2 on a timescale of 5 × 104 s. During the flare, the increase in the hard X-ray flux clearly lagged behind that observed in the soft X-rays, with the maximum lag of 2.3 × 104 s observed between the 0.3-1 keV and 5-10 keV bands. Furthermore, we discovered that the temporal profile of the flare clearly changes with energy, being more symmetric at higher energies. From the spectral fitting of multiwavelength data assuming a one-zone, homogeneous synchrotron self-Compton model, we obtain a magnetic field strength B ~ 0.047 G and an emission region size R = 3.0 × 1016 cm for an appropriate beaming with a Doppler factor of δ = 20. This value of B is in good agreement with an independent estimate through the model fit to the observed time lag ascribing the energy-dependent variability to the differential acceleration timescale of relativistic electrons provided that the gyrofactor ξ is 105.

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