Boyan Chen (NTHU), Geoffrey C. Bower (ASIAA), Jason Dexter (Colorado), Sera Markoff (Amsterdam), Anthony Ridenour (Keck) and Huei-Ru Vivien Chen (NTHU)
A big question for Active Galactic Nuclei (AGN) is whether there is a relation between the accretion and the mass scale of the center black hole, the emission coming from the accretion disk, the outflow and jet cross all the electromagnetic spectrum, therefore the flux variability provide a good probe to investigate the accretion and outflow physics. Previous studies found that there is a relation between power spectrum break time scale and black hole mass and luminosity in X-ray and NIR variability (McHardy et al. 2006 & Meyer et al.2009). In Submillimeter wavelength (230 GHz), Dexter et al. 2014 revealed a characteristic time scale of Sgr A* about 8 hours, which is consistent with the viscous time scale. Bower et al. 2015 investigated 413 sources in SMA calibrator list including different type of AGN and found that there seem to be a linear relationship between black hole mass and τ for low luminosity AGN (LLAGN). To exam this linear relationship for LLAGN, we monitored the light curve of six LLAGNs. For Cen A, combine the SMA calibrator list with our observation, we have the light curve spanned about 13 years. The observation spanned 40 month for M84, NGC4278, NGC4579. We also have the light curve for NGC4552 and NGC4579 which spanned about 12 month. We present the preliminary result of these light curve and the analysis of the characteristic time scale.