to an X-ray luminosity $L_X=5.1\times10^{40}$ergs$^{-1}$.

The X-ray light curve is shown in Figure \[fig:hr\]. AT2019qiz is reasonably well detected in X-rays for around 50 days after optical maximum. At later times, we find that the low count rate requires binning on a timescale greater than the maximum permitted by the online tools. Therefore beyond 50 days, we derive the flux offline using a single binned image, rather than the automated analysis software. The 0.3-10keV light curve peaks around 20 days after optical maximum and declines quickly thereafter.

We calculate the hardness ratio (where sufficient counts are available) as $(H-S)/(H+S)$, where $S$ is the count rate in the $0.3-2$keV band and $H$ the count rate in the $2-10$keV band; these ranges have been chosen to match @Auchettl2017. AT2019qiz exhibits an unusually hard ratio at early times, with $(H-S)/(H+S)=0.2\pm0.3$, but as the X-rays fade they also soften, reaching $(H-S)/(H+S)=-0.4\pm0.3$ by $\approx 50$ days after peak. This latter value is typical of the TDE sample studied by @Auchettl2017, whereas a positive ratio has only been seen previously in the jetted TDE J1644+57 [@Zauderer2011].

Optical spectroscopic data
--------------------------

Spectra of AT2019qiz were obtained from the 3.6-m New Technology Telescope (NTT), using EFOSC2 with Grism\#11, 