C. CHEUNG, C.; D. SCARGLE, J.; D. BLANDFORD, R.; BULMASH, D.; CIPRINI, S.; H. D. CORBET, R.; E. FALCO, E.; J. MARSHALL, P.; AJELLO, Marco; BASTIERI, D.; CHEKHTMAN, A.; D'AMMANDO, F.; GIROLETTI, M.; E. GROVE, J.; LOTT, B.; ORIENTI, M.; S. PERKINS, J.; RAZZANO, M.; J. THOMPSON, D.; S. WOOD, K.

doi:10.1088/2041-8205/782/2/L14

Métadonnées

Afficher la notice complète

Licence d’utilisation du document

Langue

Article de revue

Ce document a été publié dans

The Astrophysical journal letters. 2014, vol. 782, p. L14

Bristol : IOP Publishing

Résumé en anglais

Using data from the Fermi Large Area Telescope (LAT), we report the first clear gamma-ray measurement of a delay between flares from the gravitationally lensed images of a blazar. The delay was detected in B0218+357, a known double-image lensed system, during a period of enhanced gamma-ray activity with peak fluxes consistently observed to reach >20-50 times its previous average flux. An auto-correlation function analysis identified a delay in the gamma-ray data of 11.46 +/- 0.16 days (1 sigma) that is ~1 day greater than previous radio measurements. Considering that it is beyond the capabilities of the LAT to spatially resolve the two images, we nevertheless decomposed individual sequences of superposing gamma-ray flares/delayed emissions. In three such ~8-10 day-long sequences within a ~4-month span, considering confusion due to overlapping flaring emission and flux measurement uncertainties, we found flux ratios consistent with ~1, thus systematically smaller than those from radio observations. During the first, best-defined flare, the delayed emission was detailed with a Fermi pointing, and we observed flux doubling timescales of ~3-6 hrs implying as well extremely compact gamma-ray emitting regions.< Réduire

Mots clés en anglais

galaxies: active

gamma rays: galaxies

gravitational lensing: strong

quasars: individual (B0218+357)

Métadonnées

Licence d’utilisation du document

Fermi-LAT Detection of Gravitational Lens Delayed Gamma-ray Flares from Blazar B0218+357

Langue

Ce document a été publié dans

Résumé en anglais

Mots clés en anglais

DOI

Origine

Unités de recherche