We present a series of simulations to demonstrate that high-fidelity velocity-delay maps of the emission-line regions in active galactic nuclei can be obtained from time-resolved spectrophotometric data sets like those that will arise from the proposed Kronos satellite .
While previous reverberation-mapping experiments have established the size scale R of the broad emission-line regions from the mean time delay \tau = R / c between the line and continuum variations and have provided strong evidence for supermassive black holes , the detailed structure and kinematics of the broad-line region remain ambiguous and poorly constrained .
Here we outline the technical improvements that will be required to successfully map broad-line regions by reverberation techniques .
For typical AGN continuum light curves , characterized by power-law power spectra P ( f ) \propto f ^ { - \alpha } with \alpha = -1.5 \pm 0.5 , our simulations show that a small UV/optical spectrometer like Kronos will clearly distinguish between currently viable alternative kinematic models .
From spectra sampling at time intervals \Delta t and sustained for a total duration T _ { dur } , we can reconstruct high-fidelity velocity-delay maps with velocity resolution comparable to that of the spectra , and delay resolution \Delta \tau \approx 2 \mbox { $ \Delta t$ } , provided T _ { dur } exceeds the BLR crossing time by at least a factor of three .
Even very complicated kinematical models , such as a Keplerian flow with superimposed spiral wave pattern , are cleanly resolved in maps from our simulated Kronos datasets .
Reverberation mapping with Kronos data is therefore likely deliver the first clear maps of the geometry and kinematics in the broad emission-line regions 1–100 microarcseconds from supermassive black holes .