A NUSTAR-XMM VIEW OF THE RESOLVED X-RAY BINARY POPULATION IN THE FIREWORKS GALAX

What dictates the formation of luminous black hole (BH) versus neutron star (NS)Xray binaries (XRBs)? Recent studies have shown that some ultraluminous Xraysources in starburst and high specific star formation rate (sSFR) galaxies arepulsars, while low sSFR galaxies such as M31 have a dearth of accreting BHs.These discoveries have challenged our understanding of XRB evolution and theassociated accretion processes. We request a 420 ks NuSTAR observationsimultaneous with a 50 ks XMMNewton observation of the starburst galaxy NGC6946 (The Fireworks Galaxy) to characterize the accreting BH and NS populationsand investigate the black hole fraction at luminosities below the NS Eddingtonlimit. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]