Fast on-the-fly scanning of the solar disk with AtLAST

The solar continuum radiation at wavelengths expected to be observed by the Atacama Large Aperture Submillimeter Telescope (AtLAST) originates in the chromosphere. The chromosphere of the Sun is highly dynamic and evolves on short timescales, thus prohibiting meaningful observations to have long integration and scan times. Fast on-the-fly scanning techniques are already used by facilities such as the Atacama Large Millimeter/submillimeter Array (ALMA), completing a scan of the full solar disk in ?10 minutes by utilising its total power (TP) antennae. With AtLAST's smaller beam, a similar scan would take considerably longer, making it problematic in view of the short dynamical timescales of the solar chromosphere. A sufficiently large multi-pixel detector could reduce the needed scan time considerably, ideally to second time scales. Utilising the maria code, a powerful general-purpose telescope simulator, we are able to realistically simulate solar observations with AtLAST, and thoroughly explore how instrumental properties, scanning strategies and detector counts affect the full-disk observations at the different frequency bands planned for AtLAST. With current pixel count estimates for AtLAST instruments, we find that large regions can be instantaneously observed, even at 650 GHz, the highest frequency we consider here. This could prove useful for long-term monitoring of Active Regions at adequate resolution, something that is not possible with current facilities. Because of this large instantaneously covered region, scanning the full solar disk at reasonable time scales is also doable. At 650 GHz scanning the full disk is found to be perfectly possible on time scales shorter than 1 min, the desired cadence of full-disk solar monitoring with AtLAST.