Gone Without a Bang: A Search for Failed Core-Collapse Supernovae in ZTF and Predictions for Rubin and Roman

Abstract

The core-collapse of massive stars (${\geq}10\ \rm M_\odot$) usually takes the form of a supernova, but in some cases may lead to a direct collapse, leading to a failed core-collapse supernova (FccSN). Wide-field time-domain surveys, such as the Zwicky Transient Facility (ZTF), are a useful tool to find such ``disappearing" stars. We use a piecewise linear function model to search the entire ZTF optical photometric catalog for FccSNe, yielding 125 ``faders" that dip significantly with a flat top and bottom flux. Although no candidates were definitively found, some of the sources exhibit promising behavior that may indicate a direct collapse event. Assuming a null result from the search, we calculate at 99\% credibility that the maximum statistical rate of FccSNe in the Milky Way is 147 per century. To contextualize these findings, we also simulate the formation of stellar populations in Milky Way-like galaxies to estimate the expected number of FccSNe observable by ZTF. This simulation predicts ZTF to observe $0.234\pm0.006$ FccSNe per century, which aligns with the lack of definitive observations in ZTF. However, we predict that similar monitoring using the Legacy Survey of Space and Time (LSST) and the Nancy Grace Roman Space Telescope's Wide Field Instrument (WFI) could enable population-level studies of nearby FccSNe.