The EGRET detection of quasar 1633 + 382

Context. Using the 1.56 m telescope at the Shanghai Observatory (ShAO), China, we monitored two sources, BL Lac object S5 0716+714 and flat spectrum radio quasar (FSRQ) 3C 273. For S5 0716+714, we report 4969 sets of CCD (Charge-coupled Device) photometrical optical observations (1369 for V band, 1861 for R band and 1739 for I band) in the monitoring time from Results. The two sources both show IDV properties for S5 0716+714. The timescales are in the range from 17.3 min to 4.82 h; for 3C 273, the timescale is ∆T = 35.6 min. Based on the periodic analysis methods, we find the periods P V = 24.24 ± 1.09 days, P R = 24.12 ± 0.76 days, P I = 24.82 ± 0.73 days for S5 0716+714, and P = 12.99 ± 0.72, 21.76 ± 1.45 yr for 3C 273. The two sources displayed the "bluer-when-brighter" spectral evolution properties. Conclusions. S5 0716+714 and 3C 273 are frequently studied objects. The violent optical variability and IDV may come from the jet. Gaussian fitting can be used to analyze IDVs. The relations between brightness (flux density) and spectrum are strongly influenced by the frequency.

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“…Based on the work of Mattox et al (1993), Fan et al (2013) deduced the lower limit of the Doppler factor (δ),…”

Section: Doppler Factormentioning

confidence: 99%

Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C 273 from 2000 to 2014

Yuan

Fan

Tao

et al. 2017

A&A

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“…The formula given by equation (3) in Mattox et al (1993) for the optical depth for an outflow that is nonrelativistic in its comoving frame, as corrected by Madejski et al (1996), is…”

Section: Flux-spectrum Correlationsmentioning

confidence: 99%

Observation of X‐Ray Variability in the BL Lacertae Object 1ES 1959+65

Giebels

Bloom

Focke

et al. 2002

ApJ

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This paper reports X-ray spectral observations of a relatively nearby (z ¼ 0:048) BL Lac object 1ES 1959+65, which is a potential TeV emitter. The observations include 31 short pointings made by the Unconventional Stellar Aspect (USA) experiment on board the Advanced Research and Global Observation Satellite (ARGOS), and 17 pointings by the Proportional Counter Array (PCA) on board the Rossi X-Ray Timing Explorer (RXTE). Most of these observations were spaced by less than 1 day. 1ES 1959+65 was detected by the ARGOS USA detector in the range 1-16 keV, and by the PCA in the 2-16 keV range but at different times. During the closely spaced RXTE observations beginning on 2000 July 28, the ending of one flare and the start of another are visible, associated with spectral changes, where the photon index C ranges between $1.4 and $1.7, and the spectrum is harder when the source is brighter. This implies that 1ES 1959+65 is an X-rayselected BL Lac type (XBL) blazar, with the X-ray emission likely to originate via the synchrotron process. The USA observations reveal another flare that peaked on 2000 November 14 and doubled the flux within a few days, again associated with spectral changes of the same form. The spectral variability correlated with the flux and timing characteristics of this object that are similar to those of other nearby BL Lac objects and suggest relativistic beaming with a Doppler factor ! 1:6 and magnetic fields on the order of a few milligauss. We also suggest that the steady component of the X-ray emission-present in this object as well as in other XBLs-may be due to the large-scale relativistic jet (such as measured by Chandra in many radio-loud active galactic nuclei) but pointing very closely to our line of sight.

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“…As Mattox [13] pointed out, the production of pairs by photon interactions (pair opacity) is important for compact γ-ray emitting regions. As Renault has also shown at this meeting (see also [11]), pair opacity of γ-rays on the IR background is also important.…”

Section: Pair Opacitymentioning

confidence: 99%

Gamma-ray emission from active galactic nuclei—an overview

Bicknell¹,

Wagner²,

Groves³

2001

AIP Conference Proceedings

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Abstract. Gamma-ray emission from AGN provides us with unprecedented insights into the physics of extragalactic jets. The emission from these jets fits naturally into the existing theoretical framework of relativistic jets as inferred from parsec scale and kiloparsec scale observations. Models of the γ-ray fluxes give us important knowledge of jet parameters, in particular magnetic fields and the size of the emitting region. For example, in the case of Markarian 501, the jet plasma is subequipartiion and the energy flux is particle dominated. Discussion of the physics of jets on the subparsec scale leads naturally to questions of jet composition. The dynamics of jets are consistent with conventional electron-proton composition if the minimum Lorentz factors, γ min > 100. Jets can be electron-positron if γ min ≈ 100.

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The EGRET detection of quasar 1633 + 382

Cited by 139 publications

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Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C 273 from 2000 to 2014

Optical monitoring of BL Lac object S5 0716+714 and FSRQ 3C 273 from 2000 to 2014

Observation of X‐Ray Variability in the BL Lacertae Object 1ES 1959+65

Gamma-ray emission from active galactic nuclei—an overview

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