STROBE-X: X-ray Timing and Spectroscopy Mission

STROBE-X is a NASA probe-class observatory designed for X-ray timing and spectroscopy in the 0.2{30 keV band, with huge collecting area and good spectral resolution. It is optimized for the study of matter in the most extreme conditions found in the Universe and addresses several key science areas including:
Probing matter spiraling into black holes (BHs) to explore the efects of strong-feld general relativity and measure the masses and spins of BHs.
X-ray reverberation mapping of BH accretion flows across all mass scales, from stellar-mass BHs in our Galaxy to supermassive BHs in active galactic nuclei.
Fully determining the ultradense matter equation of state by measuring the neutron star (NS) mass-radius relation using > 20 pulsars over an extended mass range.
Exploring cosmic chemical evolution by measuring bulk metallicity of ~100 high-redshift (z > 2) galaxy clusters.Continuously surveying the dynamic X-ray sky with large duty cycle and high spectral and time resolution to characterize source behavior over a vast range of time scales, and to enable multi-wavelength and multi-messenger studies through cross-correlation with high cadence surveys at other wavelengths and in gravitational waves and neutrinos.