Jet Precession Driven by a Supermassive Black Hole Binary System in the BL Lac Object PG 1553+113

Autor(es)

Caproni, Anderson ^[1] ; Abraham, Zulema ^[2] ; Motter, Juliana Cristina ^[2] ; Monteiro, Hektor ^[3]

Afiliação do(s) autor(es)

^[1] Univ Cruzeiro Sul, Nucleo Astrofis Teor, R Galvao Bueno 868, BR-01506000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, R Matao 1226, Cidade Univ, BR-05508900 Sao Paulo, SP - Brazil

^[3] Univ Fed Itajuba, Inst Fis & Quim, Av BPS 1303, BR-37500903 Pinheirinho, Itajuba - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Astrophysical Journal Letters; v. 851, n. 2 DEC 20 2017.
• Citações Web of Science: 9

Resumo

The recent discovery of a roughly simultaneous periodic variability in the light curves of the BL Lac object PG 1553+113 at several electromagnetic bands represents the first case of such odd behavior reported in the literature. Motivated by this, we analyzed 15 GHz interferometric maps of the parsec-scale radio jet of PG 1553 + 113 to verify the presence of a possible counterpart of this periodic variability. We used the Cross-entropy statistical technique to obtain the structural parameters of the Gaussian components present in the radio maps of this source. We kinematically identified seven jet components formed coincidentally with flare-like features seen in the.-ray light curve. From the derived jet component positions in the sky plane and their kinematics (ejection epochs, proper motions, and sky position angles), we modeled their temporal changes in terms of a relativistic jet that is steadily precessing in time. Our results indicate a precession period in the observer's reference frame of 2.24 +/- 0.03 years, compatible with the periodicity detected in the light curves of PG 1553+113. However, the maxima of the jet Doppler boosting factor are systematically delayed relative to the peaks of the main.-ray flares. We propose two scenarios that could explain this delay, both based on the existence of a supermassive black hole binary system in PG 1553+113. We estimated the characteristics of this putative binary system that also would be responsible for driving the inferred jet precession. (AU)

• Processo FAPESP: 15/50360-9 - Towards imaging the Event Horizon of a black hole (EHT)
• Beneficiário: Zulema Abraham
• Modalidade de apoio: Auxílio à Pesquisa - Regular