Extreme Scattering Events (ESEs) in the ASKAP VAST Extragalactic Survey

This webpage shows the light curves and spectral time series of the sources that were identified as potential ESE candidates in the VAST extragalactic survey. The sample is divided into three categories: Gold Sample (Quantitative and Qualitative), Silver Sample (Qualitative), and Bronze Sample. The Gold Sample consists of sources that show clear evidence of both temporal and spectral variations strongly suggesting a scattering origin. The silver sample includes sources that show evidence for temporal variations but not simultaneous spectral variations. The Bronze Sample contains sources that may have potential ESEs but the light curves shows variations in addition to what a simple Gaussian lens model might predict. A more detailed description of the selection criteria and the analysis can be found in the associated paper (Anumarlapudi et al. 2026).

Description of the plots: The top panel of each plot shows the light curve for the source. The red stars show the VAST measurements, black diamonds show the VLASS measurements and the rest show contemporary data from ASKAP at different frequencies. Upper limits are shows as down-ward pointing arrows. The purple curve shows the best fit lens model to the VAST data. The bottom panel shows the spectral index time series measurements for the source. The red stars show the individual spectra index measurements and the overlaid transparent blue region shows the Gaussian process (GP) based fit (and the 1-sigma confidence interval) to the spectral index measurements.

Credits: This webpage was conceived by Akash Anumarlapudi (akasha@unc.edu), and generated by Claude Code under the supervision of Akash.