Lucky Strikes: Unraveling the asymmetric origins of GW190814 through binary field evolution

The asymmetric nature of GW190814, particularly its mass ratio (q~0.11), has made its origin elusive. We explore binary field evolution as a potential explanation for GW190814's formation. Using the binary population synthesis code COSMIC, we backpropagate the observed parameters of GW190814 to the initial conditions of Zero Age Main Sequence (ZAMS) binary stars while simultaneously inferring the astrophysical prescriptions for common envelope evolution, stable mass transfer and natal kick kinematics that are needed for its formation and eventual merger. Our findings suggest that GW190814-like systems require peculiar SN natal kicks: 1) a low magnitude first natal kick (independent of direction) that prevents the binary from unbinding and 2) a large second natal kick with its direction along the orbital plane (small polar component). The natal kick direction is crucial at forming asymmetric GW190814-like binaries as these increase its orbital eccentricity, leading to shorter delay times, and thus enabling its merger within a Hubble time. We compute the expected merger rate for GW190814-like events that experience such a "lucky" kick and assess consistency with the latest published rates. Lastly, we present population level constraints using the latest GW observations.