2016ApJ...824L..20A

Query : 2016ApJ...824L..20A

2016ApJ...824L..20A - Astrophys. J., 824, L20-L20 (2016/June-3)

Minute-timescale >100 mev γ-ray variability during the giant outburst of quasar 3C 279 observed by Fermi-LAT in 2015 June.

ACKERMANN M., ANANTUA R., ASANO K., BALDINI L., BARBIELLINI G., BASTIERI D., BECERRA GONZALEZ J., BELLAZZINI R., BISSALDI E., BLANDFORD R.D., BLOOM E.D., BONINO R., BOTTACINI E., BRUEL P., BUEHLER R., CALIANDRO G.A., CAMERON R.A., CARAGIULO M., CARAVEO P.A., CAVAZZUTI E., CECCHI C., CHEUNG C.C., CHIANG J., CHIARO G., CIPRINI S., COHEN-TANUGI J., COSTANZA F., CUTINI S., D'AMMANDO F., DE PALMA F., DESIANTE R., DIGEL S.W., DI LALLA N., DI MAURO M., DI VENERE L., DRELL P.S., FAVUZZI C., FEGAN S.J., FERRARA E.C., FUKAZAWA Y., FUNK S., FUSCO P., GARGANO F., GASPARRINI D., GIGLIETTO N., GIORDANO F., GIROLETTI M., GRENIER I.A., GUILLEMOT L., GUIRIEC S., HAYASHIDA M., HAYS E., HORAN D., JOHANNESSON G., KENSEI S., KOCEVSKI D., KUSS M., LA MURA G., LARSSON S., LATRONICO L., LI J., LONGO F., LOPARCO F., LOTT B., LOVELLETTE M.N., LUBRANO P., MADEJSKI G.M., MAGILL J.D., MALDERA S., MANFREDA A., MAYER M., MAZZIOTTA M.N., MICHELSON P.F., MIRABAL N., MIZUNO T., MONZANI M.E., MORSELLI A., MOSKALENKO I.V., NALEWAJKO K., NEGRO M., NUSS E., OHSUGI T., ORLANDO E., PANEQUE D., PERKINS J.S., PESCE-ROLLINS M., PIRON F., PIVATO G., PORTER T.A., PRINCIPE G., RANDO R., RAZZANO M., RAZZAQUE S., REIMER A., SCARGLE J.D., SGRO C., SIKORA M., SIMONE D., SISKIND E.J., SPADA F., SPINELLI P., STAWARZ L., THAYER J.B., THOMPSON D.J., TORRES D.F., TROJA E., UCHIYAMA Y., YUAN Y. and ZIMMER S.

Abstract (from CDS):

On 2015 June 16, Fermi-LAT observed a giant outburst from the flat spectrum radio quasar 3C 279 with a peak >100 MeV flux of ∼3.6 x 10–5 photons/cm2/s, averaged over orbital period intervals. It is historically the highest γ-ray flux observed from the source, including past EGRET observations, with the γ-ray isotropic luminosity reaching ∼1049 erg/s. During the outburst, the Fermi spacecraft, which has an orbital period of 95.4 minutes, was operated in a special pointing mode to optimize the exposure for 3C 279. For the first time, significant flux variability at sub-orbital timescales was found in blazar observations by Fermi-LAT. The source flux variability was resolved down to 2-minute binned timescales, with flux doubling times of less than 5 minutes. The observed minute-scale variability suggests a very compact emission region at hundreds of Schwarzschild radii from the central engine in conical jet models. A minimum bulk jet Lorentz factor (Γ) of 35 is necessary to avoid both internal γ-ray absorption and super-Eddington jet power. In the standard external radiation Comptonization scenario, Γ should be at least 50 to avoid overproducing the synchrotron self-Compton component. However, this predicts extremely low magnetization (∼5 x 10–4). Equipartition requires Γ as high as 120, unless the emitting region is a small fraction of the dissipation region. Alternatively, we consider γ rays originating as synchrotron radiation of γe ∼ 1.6 x 106 electrons, in a magnetic field B ∼ 1.3 kG, accelerated by strong electric fields E ∼ B in the process of magnetoluminescence. At such short distance scales, one cannot immediately exclude the production of γ-rays in hadronic processes.

Abstract Copyright: © 2016. The American Astronomical Society. All rights reserved.

Journal keyword(s): galaxies: active - galaxies: jets - gamma rays: galaxies - quasars: individual: 3C 279 - radiation mechanisms: non-thermal

Simbad objects: 7

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Number of rows : 7
N Identifier Otype ICRS (J2000)
RA 		ICRS (J2000)
DEC 		Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026 		#notes
1 IC 310 AGN 03 16 42.9787569912 +41 19 29.615579544   14.3       ~ 311 2
2 M 1 SNR 05 34 31.8 +22 01 03           ~ 6516 1
3 7C 122223.5+213929 Bla 12 24 54.4583146056 +21 22 46.385507388   17.56 17.50 18.2   ~ 770 2
4 3C 279 Bla 12 56 11.16657958 -05 47 21.5251510   18.01 17.75 15.87   ~ 3205 2
5 Z 225-7 BLL 16 53 52.21668403 +39 45 36.6088754 14.09 14.15 13.29 8.26   ~ 2304 2
6 PKS J2158-3013 BLL 21 58 52.0652249880 -30 13 32.118447792   13.36 13.09 12.62   ~ 1829 1
7 3C 454.3 Bla 22 53 57.7480438728 +16 08 53.561508864   16.57 16.10 15.22   ~ 3004 2

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