A NICER Look at X-ray Binaries

NICER is the new premier X-ray timing instrument onboard the International Space Station, having been installed in the summer of 2017. NICER offers an order of magnitude better time fidelity than any predecessor X-ray instrument. For spectra, NICER provides CCD-like energy resolution and sensitivity to soft X-rays, low background, and large collecting area, all with negligible pileup for even Crab-bright sources. NICER is poised to make leading contributions to fundamental topics in the X-ray binary field including constraining neutron-star equation of state, measuring black-hole spins, discerning accretion flow structure using quasi-periodic oscillations (QPO), and mapping disk-coronal geometry. I will present some of NICER's first results on black hole microquasar and neutron star systems which showcase the power of NICER for X-ray spectral-timing investigations.