A Possible Optical Quasiperiodic Oscillation of 134 days in the Radio-loud Narrow-line Seyfert 1 Galaxy TXS 1206+549 at z = 1.34

Abstract

Here we report an optical quasiperiodic oscillation (QPO) with a period of ∼134 days detected in g- and r-band light curves of the narrow-line Seyfert 1 galaxy TXS 1206+549 at a redshift of 1.34 with data from observations at the Zwicky Transient Facility (ZTF). After considering the trial factor, the significance levels in the two bands are 3.1σ and 2.6σ, respectively. The QPO signal presents about 10 cycles ranging from 2018 March to 2021 December, thus lasting ∼4 yr. A nearly sinusoidal profile also appears in the folded light curves by using a phase-resolved analysis. Interestingly, in the simultaneous light curve with the timescale of ZTF observations, a potential periodic signal with a similar period is detected in the o-band light curve from Asteroid Terrestrial-impact Last Alert System data; additionally, a weak peak is also detected at a similar period in the γ-ray light curve obtained from Fermi Gamma-ray Space Telescope data. Some potential origins of periodicities in active galactic nuclei are discussed for the QPO reported here.

Superluminal Motion and Jet Parameters in the Gamma-ray-Emitting Narrow-Line Seyfert 1 Galaxy TXS 1206+549

“…Most recently, the presence of a quasiperiodic oscillation (QPO) with a period of about 134 d in the Zwicky Transient Facility optical light curve of TXS 1206+549 was proposed [23]. The signal was present between 2018 and 2021.…”