Multiwavelength Cross-Correlation Using Millimeter AGN Light Curves from the Atacama Cosmology Telescope

We present a pilot multiwavelength cross-correlation analysis of the blazar PKS 0208-512 between 2018 and 2023 using millimeter data from the Atacama Cosmology Telescope (ACT) and the Atacama Large Millimeter Array, optical data from the All-Sky Automated Survey for Supernovae, and γ-ray data from the Fermi Large Area Telescope. We report a near-zero time-lag between the optical and γ-ray bands, consistent with leptonic emission models, while the millimeter emission lags by a few weeks, suggesting millimeter emission originates from farther downstream in the jet. With the upcoming release of an ACT catalogue containing over 200 blazar light curves, these results highlight the potential of these light curves for time-domain active galactic nuclei studies and provide a foundation for extending this analysis to a larger blazar sample.