We review the reports of possible year-long quasi-periodicities of BL Lac objects in the γ-ray and optical bands, and present a homogeneous time analysis of the light curves of PKS2155−304, PG1553+113, and BL Lac. Based on results from a survey covering the entire Fermi γ-ray sky we have estimated the fraction of possible quasi-periodic BL Lac objects. We compared the cyclical behaviour in BL Lac objects with that derived from the search of possible optical periodicities in quasars, and find that at z . 1 the cosmic density of quasi-periodic BL Lac objects is larger than that of quasi-periodic quasars. If the BL Lac quasi-periodicities were due to a supermassive binary black hole (SBBH) scenario, there could be a tension with the upper limits on the gravitational wave background measured by the pulsar timing array. The argument clearly indicates the difficulties of generally associating quasi-periodicities of BL Lac objects with SBBHs.
Sandrinelli, A., Covino, S., Treves, A., Holgado, A., Sesana, A., Lindfors, E., et al. (2018). Quasi-periodicities of BL Lacertae objects. ASTRONOMY & ASTROPHYSICS, 615.
Citazione: | Sandrinelli, A., Covino, S., Treves, A., Holgado, A., Sesana, A., Lindfors, E., et al. (2018). Quasi-periodicities of BL Lacertae objects. ASTRONOMY & ASTROPHYSICS, 615. | |
Tipo: | Articolo in rivista - Articolo scientifico | |
Carattere della pubblicazione: | Scientifica | |
Presenza di un coautore afferente ad Istituzioni straniere: | Si | |
Titolo: | Quasi-periodicities of BL Lacertae objects | |
Autori: | Sandrinelli, A; Covino, S; Treves, A; Holgado, A; Sesana, A; Lindfors, E; Ramazani, V | |
Autori: | ||
Data di pubblicazione: | 2018 | |
Lingua: | English | |
Rivista: | ASTRONOMY & ASTROPHYSICS | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1051/0004-6361/201732550 | |
Appare nelle tipologie: | 01 - Articolo su rivista |