The re-analysis of quasi-periodic oscillation of the blazar J1359+4011

• We choose structure function method and discrete correlation function method to investigate the possible period of J1359+4011 in 15 GHz.
• We find a possible quasi-periodic oscillation of about 120–130 days.
• The instabilities in the accretion flow and global p-mode oscillations in a thick disc are possible reasons for this observed behavior.

J1359+4011 is a flat spectral radio quasar monitored by the Owens Valley Radio Observatory 40 m radio telescope since 2008. The light curve of J1359+4011 in 15 GHz shows a possible quasi-periodic behavior by visual inspection. In order to confirm this quasi-periodic behavior, we utilize two classical methods: structure function method and discrete correlation function method, to investigate the possible time-scale of oscillation in the time series of J1359+4011. The analytical result shows a possible time-scale of oscillation of 120–130 days. The instabilities in the accretion flow could be a possible explanation for the modulation of the light curve; and global p-mode oscillations in a thick disc could be another possible reason for this behavior.