<i>FERMI</i>
                    LARGE AREA TELESCOPE DETECTION OF GRAVITATIONAL LENS DELAYED γ-RAY FLARES FROM BLAZAR B0218+357

Cheung, C. C.; Larsson, Stefan; Scargle, Jeffrey D.; Amin, Mustafa A.; Blandford, R. D.; Bulmash, Daniel; Chiang, J.; Ciprini, S.; Corbet, R. H. D.; Falco, E.; Marshall, Phil; Wood, D. L.; Ajello, M.; Bastieri, D.; Chekhtman, A.; D’Ammando, F.; Giroletti, M.; Grove, J. E.; Lott, B.; Ojha, R.; Orienti, M.; Perkins, J. S.; Razzano, M.; Smith, A. W.; Thompson, D. J.; Wood, K. S.

doi:10.1088/2041-8205/782/2/l14

Cited by 70 publications

(90 citation statements)

References 42 publications

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“…Contrary to Cheung et al (2014), we do not find evidence for the "orphan" sub-flares, with no associated delayed emission found in their analysis in shorter, 6-h time bins. The solution to Eq.…”

Section: Therein)contrasting

confidence: 99%

“…2.2), and can thus be attributed to the intrinsic variability in the leading image of B0218+357. A similar variability time scale was also found during the 2012 flaring episode by Cheung et al (2014). This fast variability constrains the linear source size to (Celotti et al 1998;Neronov et al 2008) R γ cτ rise Γ 2 /(1 + z) 2 × 10 14 Γ 2 τ rise 10 4 s cm,…”

Section: Comparison Of the Microlensing Constraintsupporting

confidence: 76%

“…We note that a similar behaviour of the magnification factor during the 2012 flare can be also seen in the analysis of Cheung et al (2014), although the superposition of the leading and delayed flaring components do not allow them to draw firm conclusions (Cheung et al 2014, see Fig. 4 …”

Section: Gamma Ray Magnification Factor Ratiosupporting

confidence: 61%

“…The microlensing data in the optical and X-ray continuum and line emission allow the structure of the accretion flow to be probed from its outer to inner regions (even close to the black hole; Eigenbrod et al 2008;Dai et al 2010;Blackburne et al 2011;Chartas et al 2012), locate the lineemission regions within the AGN central engine (Abajas et al 2002;Guerras et al 2013) and/or the properties of the lensing galaxy (Mediavilla et al 2015) to be probed. Only two strongly lensed blazars are detected in the GeV energy band by the Fermi Large Area Telescope (LAT; Abdo et al 2015;Cheung et al 2014). The microlensing effect has already been discussed in the literature for one of the two sources, PKS 1830-211 (Donnarumma et al 2011;Abdo et al 2015), and was recently detected (Neronov et al 2015), limiting the source size to being not larger than 10−100 Schwarzschild radii of the supermassive black hole that is powering the source.…”

Section: Introductionmentioning

confidence: 97%

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Microlensingconstraintson the size of the gamma-ray emission region in blazar B0218+357

Vovk

Neronov

2016

A&A

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Context.Observations of the effect of microlensing in gravitationally lensed quasars could potentially be used to study the structure of the source on very small distance scales -down to the size of the supermassive black hole, that powers the quasar activity. Aims. We search for the microlensing effect in the γ-ray band using the signal from a gravitationally lensed blazar, B0218+357. Methods. We develop a method to deconvolve the contributions from the two images of the source, which allows us to reconstruct the flaring light curve in the γ-ray band. We use this method to study the evolution of the magnification factor ratio between the two images throughout the flaring episodes. We interpret the time variability of the ratio as a signature of the microlensing effect and derive constraints on the physical parameters of the γ-ray source by comparing the observed variability properties of the magnification factor ratio with those derived from numerical simulations of the microlensing caustics networks. Results. We find that the magnification factor ratio experienced a change characteristic for a caustic-crossing microlensing event that occurred during a 100 d flaring period in 2012. It changed again between 2012 and a recent flaring episode in 2014. We use the measurement of the maximal magnification and duration of the caustic-crossing event to derive an estimate of the projected size of the γ-ray emission region in B0218+357, R γ ∼ 10 14 −10 15 cm. This estimate is compatible with a complementary estimate found from the minimal variability time scale. The microlensing/minimal variability time scale measurements of the source size suggest that the γ-ray emission is produced at the base of the blazar jet, in the direct vicinity of the central supermassive black hole.

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Section: Therein)contrasting

confidence: 99%

Section: Comparison Of the Microlensing Constraintsupporting

confidence: 76%

Section: Gamma Ray Magnification Factor Ratiosupporting

confidence: 61%

Section: Introductionmentioning

confidence: 97%

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Microlensingconstraintson the size of the gamma-ray emission region in blazar B0218+357

Vovk

Neronov

2016

A&A

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“…Although the angular resolution of this instrument is not sufficient to separate the two lensed images A and B, it was still possible to identify individual flares and their delayed counterparts in the summed (A + B) time series. The resulting time delay [8] was longer than the previous determinations (11.46 ± 0.16 days − 1 σ) and statistically inconsistent with the [5] value.…”

Section: Introductioncontrasting

confidence: 90%

Polarization Monitoring of the Lens System JVAS B0218+357

Biggs

Browne

2017

Galaxies

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Abstract:Monitoring of the lens system JVAS B0218+357 with the Fermi Gamma-ray Space Telescope measured a different time delay to that derived from radio observations. We have re-analysed three months of archival Very Large Array data to produce variability curves with an average sampling of one epoch per day in total flux, polarized flux and polarization position angle (PPA) at 15, 8.4 and 5 GHz. The variability is particularly strong in polarized flux. Dense sampling and improved subtraction of the Einstein ring has allowed us to produce superior variability curves and a preliminary analysis has resulted in a time delay (11.5 days) which agrees well with the γ-ray value. Both images of 0218+357 are subject to strong Faraday rotation and depolarization as a result of the radio waves passing through the interstellar medium of the spiral lens galaxy. Our data reveal frequency-dependent variations in the PPA that are different in each image and which must therefore result from variable Faraday rotation in the lens galaxy on timescales of a few days. Our analysis has revealed systematic errors in the polarization position angle measurements that strongly correlate with hour angle. Although we have been able to correct for these, we caution that all VLA polarization observations are potentially affected.

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Gravitational Lensing in Theories with Lorentz Invariance Violation

Glicenstein,

Perlick

2023

Modified and Quantum Gravity

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FERMI LARGE AREA TELESCOPE DETECTION OF GRAVITATIONAL LENS DELAYED γ-RAY FLARES FROM BLAZAR B0218+357

Cited by 70 publications

References 42 publications

Microlensingconstraintson the size of the gamma-ray emission region in blazar B0218+357

Microlensingconstraintson the size of the gamma-ray emission region in blazar B0218+357

Polarization Monitoring of the Lens System JVAS B0218+357

Gravitational Lensing in Theories with Lorentz Invariance Violation

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