Tail revisions exceed three times the quoted error sum in 13 of 139 selected CHIME bursts

We compare scattering tails for the same events in CHIME/FRB Catalogs 1 and 2. We convert Catalog 1 estimates from 600 MHz to 400.1953125 MHz with the catalog frequency exponent of -4. In 13 of 139 selected positive-tail pairs, the absolute revision exceeds three times the sum of quoted errors. A source bootstrap interval for the fraction is 5.0 to 14.5 percent. Ten of 132 events with one fitted component in both releases exceed the bound. Marginal tail distributions remain similar. The error sum bounds the standard deviation of a difference for any covariance if marginal errors are valid. This is a processing sensitivity test. It does not establish a new source or a change in plasma. Shared observations, selected positive tails, fit model choices and absent raw-spectrum or independent telescope checks limit interpretation. Original code, aggregate evidence, source hashes and retrieval steps are included. External records remain outside the bundle.

astronomy · CHIME · fast radio bursts · scattering · processing sensitivity · paired comparisons