The Spectral Energy Distributions of Fermi Blazars

Jiang, Fan; Yang, Jiang-He; Liu, Y.; Luo, Guangchun; Lin, Chao; Yuan, Yu-Hai; Xiao, H. B.; Zhou, A. Y.; Tao, Hua; Pei, Z. Y.

doi:10.3847/0067-0049/226/2/20

Cited by 160 publications

(196 citation statements)

References 73 publications

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“…The correlation between γ-rays and radio bands suggests a strong beaming effect in γ-rays (Dondi & Ghisellini 1995;Fan et al 1998;Huang et al 1999;Cheng et al 2000;Fan et al 2016a), and the beaming factors (or Doppler factors) are estimated for some γ-ray loud blazars based on their rapid γ-ray variability time scale, X-ray and γ-ray emissions ( Mattox et al 1993, von Montigny et al 1995, Cheng, et al 1999Fan et al 1999;2013;2014;Fan 2005 ). In addition, a useful method to estimate Doppler factors may be found in a work (Lähteenimäki & Valtaoja 1999), followed by many other works (Fan et al 2009;Hovatta et al 2009;Lister et al 2009a;Savolainen et al 2010).…”

Section: Introductionmentioning

confidence: 99%

“…In this Letter we investigate the relationship between the observed γ-ray luminosity and the peak frequency and those among their intrinsic values for a sample of Fermi blazars (Fan et al 2016a) with available Doppler factors. The sample properties are presented in section 2, the results in section 3 while in section 4 we give our conclusions.…”

Section: Introductionmentioning

confidence: 99%

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Intrinsic Correlations for Flaring Blazars Detected by Fermi

Jiang

Yang

Xiao

et al. 2017

ApJL

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Blazars are an extreme subclass of active galactic nuclei. Their rapid variability, luminous brightness, superluminal motion, and high and variable polarization are probably due to a beaming effect. However, this beaming factor (or Doppler factor) is very difficult to measure. Currently, a good way to estimate it is to use the time scale of their radio flares. In this Letter, we use multiwavelength data and Doppler factors reported in the literatures for a sample of 86 flaring blazars detected by Fermi to compute their intrinsic multiwavelength data and intrinsic spectral energy distributions, and investigate the correlations among observed and intrinsic data. Quite interestingly, intrinsic data show a positive correlation between luminosity and peak frequency, in contrast with the behavior of observed data, and a tighter correlation between γ-ray luminosity and the lower energy ones. For flaring blazars detected by Fermi, we conclude that (1) Observed emissions are strongly beamed; (2) The anti-correlation between luminosity and peak frequency from the observed data is an apparent result, the correlation between intrinsic data being positive; and (3) Intrinsic γ-ray luminosity is strongly correlated with other intrinsic luminosities.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Intrinsic Correlations for Flaring Blazars Detected by Fermi

Jiang

Yang

Xiao

et al. 2017

ApJL

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“…For the sources indicating a spectral upturn, we can approximate LC LX = 4πD 2 L fX where fX are the X-ray fluxes obtained from the spectral fits and listed in Table 3. We take LS based on the observed synchrotron peak flux densities (Fan et al 2016 and references therein) for PKS 0235+164, PKS 0537−441, S5 0716+714, OJ 287, ON 231 and BL Lac and LS = 4πD 2 L fR based on a 1.4 GHz flux density of 4 × 10 −4 Jy (Tingay et al 2003) for PKS 0426−380. Input parameters include m9 = 1,ṁ = 0.1 − 0.3, δ = 6, η = 0.007, TT,3 = 0.2 (based on a typical range of torus temperatures between 138 -300 K; Cleary et al (2007)) and the resulting estimates of B are presented in Table 6.…”

Section: +714mentioning

confidence: 99%

Signature of inverse Compton emission from blazars

Gaur

Mohan

Wierzcholska

et al. 2017

Monthly Notices of the Royal Astronomical Society

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Blazars are classified into high, intermediate and low energy peaked sources based on the location of their synchrotron peak. This lies in infra-red/optical to ultra-violet bands for low and intermediate peaked blazars. The transition from synchrotron to inverse Compton emission falls in the X-ray bands for such sources. We present the spectral and timing analysis of 14 low and intermediate energy peaked blazars observed with XMMNewton spanning 31 epochs. Parametric fits to X-ray spectra helps constrain the possible location of transition from the high energy end of the synchrotron to the low energy end of the inverse Compton emission. In seven sources in our sample, we infer such a transition and constrain the break energy in the range 0.6 10 keV. The Lomb-Scargle periodogram is used to estimate the power spectral density (PSD) shape. It is well described by a power law in a majority of light curves, the index being flatter compared to general expectation from AGN, ranging here between 0.01 and 1.12, possibly due to short observation durations resulting in an absence of long term trends. A toy model involving synchrotron self-Compton (SSC) and external Compton (EC; disk, broad line region, torus) mechanisms are used to estimate magnetic field strength 0.03 -0.88 G in sources displaying the energy break and infer a prominent EC contribution. The timescale for variability being shorter than synchrotron cooling implies steeper PSD slopes which are inferred in these sources.

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“…3C66A, 2FGL J0222.6 + 4302 (ISP BL) This is an intermediate synchrotron peaked BL Lac object (ISP BL, Abdo et al 2010;Fan et al 2016) and a TeV γ-ray source. Optical variability at short time scales has been reported for this source (Xie et al 1994).…”

Section: Comments On Individual Sourcesmentioning

confidence: 99%

Radio and optical intra-day variability observations of five blazars

Liu

Yang

Liu

et al. 2017

Monthly Notices of the Royal Astronomical Society

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We carried out a pilot campaign of radio and optical band intra-day variability (IDV) observations of five blazars (3C66A, S5 0716+714, OJ287, B0925+504, and BL Lacertae) on December 18-21, 2015 by using the radio telescope in Effelsberg (Germany) and several optical telescopes in Asia, Europe, and America. After calibration, the light curves from both 5 GHz radio band and the optical R band were obtained, although the data were not smoothly sampled over the sampling period of about four days. We tentatively analyse the amplitudes and time scales of the variabilities, and any possible periodicity. The blazars vary significantly in the radio (except 3C66A and BL Lacertae with only marginal variations) and optical bands on intra-and inter-day time scales, and the source B0925+504 exhibits a strong quasi-periodic radio variability. No significant correlation between the radio-and optical-band variability appears in the five sources, which we attribute to the radio IDV being dominated by interstellar scintillation whereas the optical variability comes from the source itself. However, the radio-and optical-band variations appear to be weakly correlated in some sources and should be investigated based on well-sampled data from future observations.

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The Spectral Energy Distributions of Fermi Blazars

Cited by 160 publications

References 73 publications

Intrinsic Correlations for Flaring Blazars Detected by Fermi

Intrinsic Correlations for Flaring Blazars Detected by Fermi

Signature of inverse Compton emission from blazars

Radio and optical intra-day variability observations of five blazars

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