The Relative Contributions of Accretion Disk versus Jet to the Optical and Mid-infrared Variability of Seyfert Galaxies

We performed a comprehensive analysis of flux and color variability in a redshift-matched sample of Seyfert galaxies, comprising 23 gamma-ray-detected narrow-line Seyfert 1 galaxies (gNLS1s), 190 non-gamma-ray-detected narrow-line Seyfert 1 galaxies (ngNLS1s), and 10 gamma-ray-detected broad-line Seyfert 1 galaxies (gBLS1s). Utilizing multiband light curves from the Zwicky Transient Facility in the g , r , and i bands, along with mid-infrared (MIR) observations in the W1 and W2 bands from the Wide-field Infrared Survey Explorer, we observed that gBLS1s exhibit more significant variability than gNLS1s, while ngNLS1s display minimal variability across both optical and MIR wavelengths. The pronounced variability in gBLS1s may be attributed to a more closely aligned jet relative to the observer’s line of sight or their comparatively lower accretion rates. In contrast, the subdued variability in ngNLS1s suggests that their flux changes are primarily driven by accretion disk instabilities. A strong correlation between optical and MIR variability amplitudes across different timescales supports the reprocessing scenario, where accretion disk emission is reemitted by surrounding dust. Furthermore, our long-term color variability analysis revealed both stronger bluer-when-brighter and redder-when-brighter (RWB) trends in the current sample, but a stronger RWB in approximately 50%, 49%, and 50% of gNLS1s, ngNLS1s, and gBLS1s, respectively, at longer optical wavelengths, and 55%, 28%, and 30% at MIR wavelengths, strengthen the reprocessing scenario. The prevalent RWB trends observed at both optical and MIR wavelengths from the current sample on longer timescales are likely associated with accretion disk instabilities.