Abstract Details
| Name: VINEET OJHA Affiliation: Kavli Institute for Astronomy and Astrophysics at Peking University, China Conference ID: ASI2025_696 Title : Temporal and spectral variability in gamma-ray and non-gamma-ray detected Seyfert 1 galaxies: Insights from optical and infrared Authors and Co-Authors : Ojha Vineet, Wu Xue-Bing, Ho Luis C. Abstract Type : Poster Abstract Category : Galaxies and Cosmology Abstract : Variability across the electromagnetic spectrum is a hallmark of active galactic nuclei (AGNs), offering unique insights into their emission mechanisms on spatial scales that are currently inaccessible to direct imaging. This variability serves as a powerful diagnostic tool, revealing critical information about AGN physics, including the spatial and temporal structure of emitting regions, accretion disk dynamics, and the properties of the central supermassive black hole. This study presents a systematic investigation of flux and color variability in optical and infrared wavelengths for a redshift-matched sample comprising gamma-ray-detected Narrow-line Seyfert 1 galaxies (gNLS1s), non-gamma-ray-detected NLS1s (ngNLS1s), and a control sample of gamma-ray-detected Broad-line Seyfert 1 galaxies (gBLS1s). Utilizing multiband light curves from the Zwicky Transient Facility (ZTF) in the optical domain and the Wide-field Infrared Survey Explorer (WISE) in the infrared, we observe that both gNLS1s and gBLS1s exhibit significant variability over timescales ranging from days to years across both wavelength regimes. In contrast, ngNLS1s display minimal variability, even on extended timescales. Our high-cadence color variability analysis using ZTF data reveals “bluer when brighter” (BWB) and “redder when brighter” (RWB) trends in 20% of gBLS1s, while 53% of gNLS1s exhibit a BWB trend. Similarly, 43% of ngNLS1s display a RWB trend. In the WISE W1-W2 color variability analysis, we find that a small fraction (13%) of gNLS1s and 30% of gBLS1s show BWB trends, whereas a predominant fraction (93%) of ngNLS1s exhibit BWB trend. These findings point to distinctive physical mechanisms in each AGN class, which appear to influence their flux and color variability across wavelengths. We will discuss potential physical mechanisms driving the observed flux and color variability in gamma-ray- and non-gamma-ray-detected Seyfert 1 subclasses, providing a deeper understanding of the complex processes shaping AGN variability in the optical and infrared. |