We report for the first time a gamma-ray and multiwavelength nearly periodic oscillation in an active galactic nucleus. Using the Fermi Large Area Telescope we have discovered an apparent quasi-periodicity in the gamma-ray flux (E > 100 MeV) from the GeV/TeV BL Lac object PG 1553+113. The marginal significance of the 2.18 +/- 0.08 year period gamma-ray cycle is strengthened by correlated oscillations observed in radio and optical fluxes, through data collected in the Owens Valley Radio Observatory, Tuorla, Katzman Automatic Imaging Telescope, and Catalina Sky Survey monitoring programs and Swift-UVOT. The optical cycle appearing in similar to 10 years of data has a similar period, while the 15 GHz oscillation is less regular than seen in the other bands. Further long-term multiwavelength monitoring of this blazar may discriminate among the possible explanations for this quasi-periodicity.
MULTIWAVELENGTH EVIDENCE FOR QUASI-PERIODIC MODULATION IN THE GAMMA-RAY BLAZAR PG 1553+113 / Ackermann M; Ajello M; Albert A; Atwood WB; Baldini L; Ballet J; Barbiellini G; Bastieri D; Gonzalez JB; Bellazzini R; Bissaldi E; Blandford RD; Bloom ED; Bonino R; Bottacini E; Bregeon J; Bruel P; Buehler R; Buson S; Caliandro GA; Cameron RA; Caputo R; Caragiulo M; Caraveo PA; Cavazzuti E; Cecchi C; Chekhtman A; Chiang J; Chiaro G; Ciprini S; Cohen-Tanugi J; Conrad J; Cutini S; DAmmando F; de Angelis A; de Palma F; Desiante R; Di Venere L; Dominguez A; Drell PS; Favuzzi C; Fegan SJ; Ferrara EC; Focke WB; Fuhrmann L; Fukazawa Y; Fusco P; Gargano F; Gasparrini D; Giglietto N; Giommi P; Giordano F; Giroletti M; Godfrey G; Green D; Grenier IA; Grove JE; Guiriec S; Harding AK; Hays E; Hewitt JW; Hill AB; Horan D; Jogler T; Johannesson G; Johnson AS; Kamae T; Kuss M; Larsson S; Latronico L; Li J; Li L; Longo F; Loparco F; Lott B; Lovellette MN; Lubrano P; Magill J; Maldera S; Manfreda A; Max-Moerbeck W; Mayer M; Mazziotta MN; McEnery JE; Michelson PF; Mizuno T; Monzani ME; Morselli A; Moskalenko IV; Murgia S; Nuss E; Ohno M; Ohsugi T; Ojha R; Omodei N; Orlando E; Ormes JF; Paneque D; Pearson TJ; Perkins JS; Perri M; Pesce-Rollins M; Petrosian V; Piron F; Pivato G; Porter TA; Raino S; Rando R; Razzano M; Readhead A; Reimer A; Reimer O; Schulz A; Sgro C; Siskind EJ; Spada F; Spandre G; Spinelli P; Suson DJ; Takahashi H; Thayer JB; Thompson DJ; Tibaldo L; Torres DF; Tosti G; Troja E; Uchiyama Y; Vianello G; Wood KS; Wood M; Zimmer S; Berdyugin A; Corbet RHD; Hovatta T; Lindfors E; Nilsson K; Reinthal R; Sillanpaa A; Stamerra A; Takalo LO; Valtonen MJ. - In: THE ASTROPHYSICAL JOURNAL LETTERS. - ISSN 2041-8205. - STAMPA. - 813:2(2015), pp. L41.41-L41.48. [10.1088/2041-8205/813/2/L41]
MULTIWAVELENGTH EVIDENCE FOR QUASI-PERIODIC MODULATION IN THE GAMMA-RAY BLAZAR PG 1553+113
D'AMMANDO, FILIPPO;
2015
Abstract
We report for the first time a gamma-ray and multiwavelength nearly periodic oscillation in an active galactic nucleus. Using the Fermi Large Area Telescope we have discovered an apparent quasi-periodicity in the gamma-ray flux (E > 100 MeV) from the GeV/TeV BL Lac object PG 1553+113. The marginal significance of the 2.18 +/- 0.08 year period gamma-ray cycle is strengthened by correlated oscillations observed in radio and optical fluxes, through data collected in the Owens Valley Radio Observatory, Tuorla, Katzman Automatic Imaging Telescope, and Catalina Sky Survey monitoring programs and Swift-UVOT. The optical cycle appearing in similar to 10 years of data has a similar period, while the 15 GHz oscillation is less regular than seen in the other bands. Further long-term multiwavelength monitoring of this blazar may discriminate among the possible explanations for this quasi-periodicity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
