New result from EXTraS: an accreting pulsar powers the ultraluminous X-ray source P13 in NGC 7793. The paper reporting the discovery has been accepted for publication by the journal MNRAS and is now in press. You can read it here, on arXiv or here, on MNRAS.
You might also want to read the Media INAF press release

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An exciting result from EXTraS: the extreme ULX in NGC 5907, one of the best intermediate mass black hole candidates, is... 
New result from EXTraS: an accreting pulsar powers the ultraluminous X-ray source P13 in NGC 7793. The paper reporting... 
Another result from the EXTraS search for X-ray pulsators: an accreting pulsar orbiting a Be star in the Large Magellanic...