data in the time domain, as there were not any background flares in the dataset. The dataset was also energy filtered between 0.2 and 12 keV for the MOS cameras and between 0.2 and 15 keV for the PN camera, using [*xmmselect*]{}. We then used [ *evigweight*]{} to apply a vignetting correction to the files and extracted spectra from each camera using [*evselect*]{}. [ *Evigweight*]{} is a standard SAS tool which properly propagates statistical errors. We use the SAS tool [*arfgen*]{} to create the ancillary response files. Vignetting is not taken into account when creating the ancillary reponse files as it is already accounted for by the weighting factor applied by [*evigweight*]{}.

In order to identify suitable regions for spectral analysis, it is first necessary to create an image. We used [*xmmselect*]{} to create an image for each camera in the 0.3–8 keV energy band, and then combined these images to generate an exposure map for each camera to correct for chip gaps.

We used a [*Chandra*]{} observation, first described by @itmismma02, to identify point sources in the image. These were then removed from the combined image and Gaussian smoothing was used. We experimented with a range of kernel sizes 