BLACK HOLES
Probing stationary spacetimes near black holes (BHs) to explore the effects of strong-field general relativity and measure the masses and spins of BHs.
STROBE-X is a 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 stationary spacetimes near black holes (BHs) to explore the effects of strong-field 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.
Enabling multi-wavelength and multi-messenger studies through cross-correlation with high cadence surveys at other wavelengths and in gravitational waves and neutrinos
Detailed simulations show that an order of magnitude larger collecting area than RXTE is needed to meet these BH and NS objectives, and a previous engineering study showed that such a capability is too large for the Explorer (EX) class and instead requires a probe-class mission. STROBE-X consists of three instruments: a 2.0 m2 soft-band (0.2–12 keV) X-ray Concentrator Array (XRCA), based on the successful heritage of NICER; and a 5.0 m2 hard-band (2–30 keV) Large Area Detector (LAD) and Wide Field Monitor (WFM), both based on the well-studied technology of ESA’s LOFT M-class mission concept. The complementary passbands of the two large-area instruments and the continuous, sensitive sky coverage of the WFM represent an extraordinarily powerful combination.