6.24 and UVOT calibration 20170922. We exclude the initial images in the $B$, $U$, $UVW1$, and $UVW2$ filters (OBSID 00012012001) due to trailing within the images. We also exclude 2 later $UVW1$ images and a $UVW2$ image due to the source being located on patches of the detector known to suffer reduced sensitivity. A correction has yet to be determined for these patches[^6].

![Stacked *Swift* XRT image (total exposure time 30ks) centred at the position of AT2019qiz, marked by a cyan cross. An X-ray source is detected at $5.6\sigma$ significance. The image has been blocked $4\times4$ and smoothed using a Gaussian kernel for display. The colour bar gives the counts per pixel.[]{data-label="fig:x"}](xray3.pdf){width="7cm"}

![Time-averaged X-ray spectrum and best-fit absorbed power-law model, used to derive the counts-to-flux conversion.[]{data-label="fig:xspec"}](xspec2.pdf){width="\columnwidth"}

![Top: XRT light curve (unabsorbed flux) in 0.3-10keV, 0.3-2keV (soft) and 2-10keV (hard) X-ray bands. The X-ray light curve peaks around 20 days after optical maximum. Bottom: evolution of the hardness ratio, defined as (hard$-$soft counts)/(hard$+$soft counts). The X-rays transition from hard to soft as the luminosity declines.[]{data-label="fig:hr"}](hr.pdf){width="\columnwidth"}

![image](all-spec.pdf){width="\textwidth"}

No host galaxy images in the UV are available for subtraction. We first estimated the host contribution using a spectral energy distribution (SED) fit for 