TITLE: GCN CIRCULAR NUMBER: 25697 SUBJECT: ZTF19abvizsw: No counterpart candidates from Swift/BAT targeted search DATE: 19/09/10 03:31:59 GMT FROM: Aaron Tohuvavohu at PSU/Swift Aaron Tohuvavohu (U Toronto) reports: We have performed a search for an un-triggered GRB counterpart to the claimed afterglow candidate ZTF19abvizsw (GCN 25616, 25643, 25658) in the Swift/BAT raw light curves. The temporal window for the search was chosen to be 2019-09-01 07:35 --- 2019-09-02 03:08 corresponding to the times of the last ZTF non-detection and of the discovery observation respectively. During this time period, the location of ZTF19abvizsw was above the Earth-limb with respect to the spacecraft (and thus a priori capable of depositing flux onto the detector) 64.2% of the time. The location was inside the BAT coded field-of-view 19% of the time. No compelling candidates were found in the BAT raw light curves with time bins of 64ms, 1 s and 1.6 s. Due to the long temporal window for the search, the average background, and thus upper-limit sensitivity, varies widely over the search window. After excising times when the spacecraft was near the South Atlantic Anomaly, the average 5-sigma flux upper limit achieved for a long GRB in the 1-s binned data with a typical spectrum corresponds to ~3 x 10^-7 erg/s/cm^2 in the BAT coded field-of-view, and approximately an order of magnitude higher for locations outside of the field-of-view. We also performed spot checks for the three candidates reported from INTEGRAL (GCN 25686). None of these candidates are seen in the Swift/BAT data.