Milli-to-Deci-Hertz Detection Prospects for Gravitational Waves from Core-Collapse Supernovae

Gravitational wave (GW) astronomy truly began with the detection of merging compact binaries. The next breakthrough lies in detecting GWs from core-collapse supernovae (CCSNe), particularly the GW linear memory -- a phenomenon arising from aspherical matter ejection and anisotropic neutrino emission during stellar collapse. In this Letter, we examine the feasibility of detecting this effect using next-generation space-based GW detectors or lunar-based GW observatories as this signature peaks below 25 Hz, which is largely inaccessible to terrestrial GW detectors due to seismic noise. Such a detection would provide fundamental insights into asymmetric matter dynamics near the collapsed core, shedding light on the stellar corpse that once represented the mass of the progenitor star and offering a front row seat to the potential formation of either a nascent neutron star progenitor or a black hole. Leveraging the longest-duration three-dimensional CCSNe simulations to date, spanning a wide range of progenitor masses, we show that space-based and lunar GW detectors present the most promising opportunities to extend the current CCSNe GW detection horizon (~ 10 kiloparsecs) to several megaparsecs. This may pave the way for regularly observing GWs from CCSNe beyond our Milky Way by utilizing the distinctive environments of space and the Moon to augment terrestrial detection efforts all the while synergistically advancing sophisticated data analysis techniques for routine GW detection.