|Description:|| This is a mosaic of images taken from roughly 30 hours of observation with AARTFAAC over the autumn of 2016. AARTFAAC operates in parallel while other users observe with the LOFAR LBA. These snapshot images were recorded at 60MHz, bandwidth of 3.2 MHz, and image integration time of 1 second. Roughly 1400 all sky images were used cover the full northern celestial hemisphere.|
Initial image calibration removes Cas.A, Cyg.A, Tau.A, and Vir.A, as well as The Sun, and most of the diffuse galactic plane (red dotted line) emission, which would otherwise dominate. A further calibration step 'bootstraps' from currently published low frequency catalogs to correct the flux scaling for each image.
The individual snap images AARTFAAC makes every second are used to detect bright low frequency transients as quickly as possible for followup observing in near real time. Mosaics such as this one allow us to monitor the total observable source population over timescales of months to years allowing us to monitor for long term variability. This also provides beautiful view of the night sky, with radio eyes!