Is there a Black Hole in any of the INTEGRAL HMXBsquestionMark

Through its hard Xray survey of the Galactic Plane, INTEGRAL has uncoveredlarge numbers of HMXBs, and many of them have not been wellstudied to date. Wepropose to observe two INTEGRAL HMXBs that have not previously shown signaturesof having a neutron star: IGR J182141318 and IGR J082623736. With XMMNewtonand NuSTAR, we will search for such signatures (pulsations, cyclotron lines,exponential cutoffs with efolding energies below virgul20 keV). If these featuresare lacking and if the source instead has a powerlaw that extends to the top ofthe NuSTAR bandpass, this would be an excellent black hole candidate andmotivation would be very strong for followup optical or IR spectroscopy todetermine the mass of the compact object. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]