Quasi periodic whispers from a transient ULX in M\,101: signatures of a fast-spinning neutron star?

Ryan T. Urquhart, Roberto Soria, Rosanne Di Stefano +7

We have studied the unusual time variability of an ultraluminous X-ray source in M 101, 4XMM J140314.2$+$541806 (henceforth, J1403), using Chandra and XMM-Newton data. Over the las…