Young Accreting Compact Objects in M31: The Combined Power of NuSTAR, Chandra, and Hubble.

摘要: We present 15 high-mass X-ray binary (HMXB) candidates in the disk of M31 for which we are able to infer compact object type, spectral type donor star, and age using multiwavelength observations from NuSTAR, Chandra, Hubble Space Telescope. The hard colors luminosities NuSTAR permit tentative classification accreting systems by distinguishing black hole neutron star systems. find hard-state holes, pulsars, non-magnetized stars associated with optical point-source counterparts similar frequency. also nine coincident globular clusters an equal number pulsars without counterparts. perform energy distribution (SED) fitting most likely HMXB candidates, finding seven one possible red helium-burning star. remaining have poor SED fits, so their companion remain unclassified. Using published formation histories, that majority candidates-X-ray sources UV-bright counterpart candidates-are found regions bursts less than 50 Myr ago, three young stellar ages (<10Myr). This is consistent studies populations Magellanic Clouds, M33, NGC 300, 2403.