학술논문
Multiwavelength observations of 3C 454.3. III. Eighteen months of AGILE monitoring of the 'Crazy Diamond'
Document Type
Working Paper
Author
Vercellone, S.; D'Ammando, F.; Vittorini, V.; Donnarumma, I.; Pucella, G.; Tavani, M.; Ferrari, A.; Raiteri, C. M.; Villata, M.; Romano, P.; Krimm, H.; Tiengo, A.; Chen, A. W.; Giovannini, G.; Venturi, T.; Giroletti, M.; Kovalev, Y. Y.; Sokolovsky, K.; Pushkarev, A. B.; Lister, M. L.; Argan, A.; Barbiellini, G.; Bulgarelli, A.; Caraveo, P.; Cattaneo, P. W.; Cocco, V.; Costa, E.; Del Monte, E.; De Paris, G.; Di Cocco, G.; Evangelista, Y.; Feroci, M.; Fiorini, M.; Fornari, F.; Froysland, T.; Fuschino, F.; Galli, M.; Gianotti, F.; Labanti, C.; Lapshov, I.; Lazzarotto, F.; Lipari, P.; Longo, F.; Giuliani, A.; Marisaldi, M.; Mereghetti, S.; Morselli, A.; Pellizzoni, A.; Pacciani, L.; Perotti, F.; Piano, G.; Picozza, P.; Pilia, M.; Prest, M.; Rapisarda, M.; Rappoldi, A.; Sabatini, S.; Soffitta, P.; Striani, E.; Trifoglio, M.; Trois, A.; Vallazza, E.; Zambra, A.; Zanello, D.; Pittori, C.; Verrecchia, F.; Santolamazza, P.; Giommi, P.; Colafrancesco, S.; Salotti, L.; Agudo, I.; Aller, H. D.; Aller, M. F.; Arkharov, A. A.; Bach, U.; Bachev, R.; Beltrame, P.; Benitez, E.; Boettcher, M.; Buemi, C. S.; Calcidese, P.; Capezzali, D.; Carosati, D.; Chen, W. P.; Da Rio, D.; Di Paola, A.; Dolci, M.; Dultzin, D.; Forne, E.; Gomez, J. L.; Gurwell, M. A.; Hagen-Thorn, V. A.; Halkola, A.; Heidt, J.; Hiriart, D.; Hovatta, T.; Hsiao, H. Y.; Jorstad, S. G.; Kimeridze, G.; Konstantinova, T. S.; Kopatskaya, E. N.; Koptelova, E.; Kurtanidze, O.; Lahteenmaki, A.; Larionov, V. M.; Leto, P.; Ligustri, R.; Lindfors, E.; Lopez, J. M.; Marscher, A. P.; Mujica, R.; Nikolashvili, M.; Nilsson, K.
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Subject
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Abstract
We report on 18 months of multiwavelength observations of the blazar 3C 454.3 (Crazy Diamond) carried out in July 2007-January 2009. We show the results of the AGILE campaigns which took place on May-June 2008, July-August 2008, and October 2008-January 2009. During the May 2008-January 2009 period, the source average flux was highly variable, from an average gamma-ray flux F(E>100MeV) > 200E-8 ph/cm2/s in May-June 2008, to F(E>100MeV)~80E-8 ph/cm2/s in October 2008-January 2009. The average gamma-ray spectrum between 100 MeV and 1 GeV can be fit by a simple power law (Gamma_GRID ~ 2.0 to 2.2). Only 3-sigma upper limits can be derived in the 20-60 keV energy band with Super-AGILE. During July-August 2007 and May-June 2008, RXTE measured a flux of F(3-20 keV)= 8.4E-11 erg/cm2/s, and F(3-20 keV)=4.5E-11 erg/cm2/s, respectively and a constant photon index Gamma_PCA=1.65. Swift/XRT observations were carried out during all AGILE campaigns, obtaining a F(2-10 keV)=(0.9-7.5)E-11 erg/cm2/s and a photon index Gamma_XRT=1.33-2.04. BAT measured an average flux of ~5 mCrab. GASP-WEBT monitored 3C 454.3 during the whole 2007-2008 period from the radio to the optical. A correlation analysis between the optical and the gamma-ray fluxes shows a time lag of tau=-0.4 days. An analysis of 15 GHz and 43 GHz VLBI core radio flux observations shows an increasing trend of the core radio flux, anti- correlated with the higher frequency data. The modeling SEDs, and the behavior of the long-term light curves in different energy bands, allow us to compare the jet properties during different emission states, and to study the geometrical properties of the jet on a time-span longer than one year.
Comment: Accepted for publication in ApJ. Adapted Abstract. 17 pages, 19 Figures, 5 Tables
Comment: Accepted for publication in ApJ. Adapted Abstract. 17 pages, 19 Figures, 5 Tables