2011A&A...534A..87R


C.D.S. - SIMBAD4 rel 1.7 - 2019.11.13CET04:23:51

2011A&A...534A..87R - Astronomy and Astrophysics, volume 534A, 87-87 (2011/10-1)

The long-lasting activity of 3C 454.3. GASP-WEBT and satellite observations in 2008-2010.

RAITERI C.M., VILLATA M., ALLER M.F., GURWELL M.A., KURTANIDZE O.M., LAEHTEENMAEKI A., LARIONOV V.M., ROMANO P., VERCELLONE S., AGUDO I., ALLER H.D., ARKHAROV A.A., BACH U., BENITEZ E., BERDYUGIN A., BLINOV D.A., BORISOVA E.V., BOETTCHER M., BRAVO CALLE O.J.A., BUEMI C.S., CALCIDESE P., CAROSATI D., CASAS R., CHEN W.-P., EFIMOVA N.V., GOMEZ J.L., GUSBAR C., HAWKINS K., HEIDT J., HIRIART D., HSIAO H.Y., JORDAN B., JORSTAD S.G., JOSHI M., KIMERIDZE G.N., KOPTELOVA E., KONSTANTINOVA T.S., KOPATSKAYA E.N., KURTANIDZE S.O., LARIONOVA E.G., LARIONOVA L.V., LETO P., LI Y., LIGUSTRI R., LINDFORS E., LISTER M., MARSCHER A.P., MOLINA S.N., MOROZOVA D.A., NIEPPOLA E., NIKOLASHVILI M.G., NILSSON K., PALMA N., PASANEN M., REINTHAL R., ROBERTS V., ROS J.A., ROUSTAZADEH P., SADUN A.C., SAKAMOTO T., SCHWARTZ R.D., SIGUA L.A., SILLANPAEAE A., TAKALO L.O., TAMMI J., TAYLOR B., TORNIKOSKI M., TRIGILIO C., TROITSKY I.S., UMANA G., VOLVACH A. and YULDASHEVA T.A.

Abstract (from CDS):

The blazar 3C 454.3 is one of the most active sources from the radio to the γ-ray frequencies observed in the past few years. We present multiwavelength observations of this source from April 2008 to March 2010. The radio to optical data are mostly from the GASP-WEBT, UV and X-ray data from Swift, and γ-ray data from the AGILE and Fermi satellites. The aim is to understand the connection among emissions at different frequencies and to derive information on the emitting jet. Light curves in 18 bands were carefully assembled to study flux variability correlations. We improved the calibration of optical-UV data from the UVOT and OM instruments and estimated the Lyα flux to disentangle the contributions from different components in this spectral region. The observations reveal prominent variability above 8GHz. In the optical-UV band, the variability amplitude decreases with increasing frequency due to a steadier radiation from both a broad line region and an accretion disc. The optical flux reaches nearly the same levels in the 2008-2009 and 2009-2010 observing seasons; the mm one shows similar behaviour, whereas the γ and X-ray flux levels rise in the second period. Two prominent γ-ray flares in mid 2008 and late 2009 show a double-peaked structure, with a variable γ/optical flux ratio. The X-ray flux variations seem to follow the γ-ray and optical ones by about 0.5 and 1d, respectively. We interpret the multifrequency behaviour in terms of an inhomogeneous curved jet, where synchrotron radiation of increasing wavelength is produced in progressively outer and wider jet regions, which can change their orientation in time. In particular, we assume that the long-term variability is due to this geometrical effect. By combining the optical and mm light curves to fit the γ and X-ray ones, we find that the γ (X-ray) emission may be explained by inverse-Comptonisation of synchrotron optical (IR) photons by their parent relativistic electrons (SSC process). A slight, variable misalignment between the synchrotron and Comptonisation zones would explain the increased γ and X-ray flux levels in 2009-2010, as well as the change in the γ/optical flux ratio during the outbursts peaks. The time delays of the X-ray flux changes after the γ, and optical ones are consistent with the proposed scenario.

Abstract Copyright:

Journal keyword(s): galaxies: active - quasars: general - quasars: individual: 3C 454.3 - galaxies: jets

Simbad objects: 5

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Number of rows : 5

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2020
#notes
1 QSO B0235+1624 BLL 02 38 38.93010 +16 36 59.2746   16.46 15.50 15.92   ~ 1367 2
2 6C 095456+654857 BLL 09 58 47.2452838930 +65 33 54.821524491     17.0 15.75   ~ 605 1
3 4C 39.49 BLL 16 53 52.21668494 +39 45 36.6089458 14.09 14.15 13.29 8.26   ~ 1876 2
4 NAME BL Lac BLL 22 02 43.2913773726 +42 16 39.978417860   15.66 14.72     ~ 1975 1
5 3C 454.3 QSO 22 53 57.74798 +16 08 53.5611   16.57 16.10 15.22   ~ 2441 2

    Equat.    Gal    SGal    Ecl

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2019.11.13-04:23:51

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