Gamma-Ray and Optical Oscillations in PKS 0537–441

Sandrinelli, A.; Covino, S.; Treves, A.

doi:10.3847/0004-637x/820/1/20

Cited by 47 publications

(43 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Possible γ-ray QPOs have been reported for several blazars (e.g., Sandrinelli et al 2014;Ackermann et al 2015;Sandrinelli et al 2016aSandrinelli et al , 2016bSandrinelli et al , 2017Zhang et al 2017aZhang et al , 2017b. However, the significance of the claimed QPOs is not very high.…”

Section: Summary and Discussionmentioning

confidence: 99%

“…So far, the Large Area Telescope (LAT; Atwood et al 2009) on board Fermi has collected gamma-rays for over 8 years. The possible quasiperiodic variabilities of blazars with periods of ∼2-3 yr have been reported in γ-ray fluxes of several blazars (e.g., Sandrinelli et al 2014;Ackermann et al 2015;Sandrinelli et al 2016aSandrinelli et al , 2016bSandrinelli et al , 2017Zhang et al 2017aZhang et al , 2017b. In particular, PKS 2155-304 has been reported to have a significance of ∼4σ (Zhang et al 2017b).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A γ-ray Quasi-periodic Modulation in the Blazar PKS 0301–243?

Zhang

Yan

Zhou

et al. 2017

ApJ

View full text Add to dashboard Cite

We report a nominally high-confidence γ-ray quasi-periodic modulation in the blazar PKS 0301-243. For this target, we analyze its Fermi-LAT Pass 8 data from 2008 August to 2017 May. Two techniques, i.e., maximum likelihood optimization and exposure-weighted aperture photometry, are used to build the γ-ray light curves. Then, both the Lomb-Scargle periodogram and the weighted wavelet Z-transform are applied to the light curves to search for period signals. A quasi-periodicity with a period of 2.1±0.3 yr appears at the significance level of s5 , although it should be noted that this putative quasi-period variability is seen in a data set that is barely four times longer. We speculate that this γ-ray quasi-periodic modulation may be evidence of a binary supermassive black hole.

show abstract

Section: Summary and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A γ-ray Quasi-periodic Modulation in the Blazar PKS 0301–243?

Zhang

Yan

Zhou

et al. 2017

ApJ

View full text Add to dashboard Cite

show abstract

“…In particular, we mention PKS 2155- 304 (Sandrinelli et al 2014b(Sandrinelli et al , 2016a, where T γ = 640 days and T opt ∼ 1 2 T γ ); PG 1553+11 (Ackermann et al 2015, where T γ = T opt = 798 days), and PKS 0537-441 (Sandrinelli et al 2016b, where T γ = 280 d and T opt ∼ 1 2 T γ ). The cases of OJ 287, 3C279, PKS 1510-089, PKS 2005-489 have also been studied.…”

Section: Introductionmentioning

confidence: 99%

Gamma-ray and optical oscillations of 0716+714, MRK 421, and BL Lacertae

Sandrinelli

Covino

Treves

et al. 2017

A&A

Self Cite

View full text Add to dashboard Cite

We examine the 2008-2016 γ-ray and optical light curves of three bright BL Lac objects, 0716+714, MRK 421, BL Lac, which exhibit large structured variability. We searched for periodicities by using a fully Bayesian approach. For two out of three sources investigated, no significant periodic variability was found. In the case of BL Lac, we detected a periodicity of ∼ 680 days. Although the signal related to this is modest, the coincidence of the periods in both gamma and optical bands is indicative of a physical relevance. Taking into consideration previous literature results, possibly related γ-ray and optical periodicities of about one year time scale are proposed in four bright γ-ray blazars out of the ten examined in detail. Compared with results from periodicity search of optical archives of quasars, the presence of quasi-periodicities in blazars may be more frequent by a large factor. This suggests the intriguing possibility that the basic conditions for their observability are related to the relativistic jet in the observer direction, but the overall picture remains uncertain.

show abstract

“…It is interesting that the observed period of PKS 0601-70 is ∼ 1.22 year, and the corrected period in the host galaxy frame is ∼0.35 year (see Table 3). It is also shorter than that reported in the previous works (e.g., Sandrinelli et al 2014;Zhang et al 2017a;Ackermann et al 2015;Zhang et al 2017b,c;Sandrinelli et al 2016a) Prokhorov & Moraghan (2017) performed a systematic search for QPOs in Fermi-LAT γ-ray sources. They reported seven blazars having possible QPOs.…”

Section: Summary and Discussionmentioning

confidence: 60%

Searching for Quasiperiodic Modulations in γ-Ray Active Galactic Nuclei

Zhang

Yan

Zhou

et al. 2020

ApJ

View full text Add to dashboard Cite

We perform a systematic search of quasi-periodic variabilities in γ-ray active galactic nuclei (AGNs) in the third Fermi Large Area Telescope source catalog (3FGL). We employe two techniques, Lomb-Scargle Periodogram (LSP) and Weighted Wavelet Z-transform (WWZ), to obtain power spectra of γ-ray light curves covering from 2008 August to 2016 December. The results show that besides several objects that have been reported in previous works, an additional source, the FSRQ PKS 0601-70 has a possible quasi-periodic variability of 450 days in its γ-ray light curves with the significance of > 3σ. The physical implications of our findings are discussed.

show abstract

Gamma-Ray and Optical Oscillations in PKS 0537–441

Cited by 47 publications

References 42 publications

A γ-ray Quasi-periodic Modulation in the Blazar PKS 0301–243?

A γ-ray Quasi-periodic Modulation in the Blazar PKS 0301–243?

Gamma-ray and optical oscillations of 0716+714, MRK 421, and BL Lacertae

Searching for Quasiperiodic Modulations in γ-Ray Active Galactic Nuclei

Contact Info

Product

Resources

About