CompactBINARIES · Compact binaries as strong gravitational wave sources and progenitors of type Ia supernovae

The accelerated expansion of the universe was one of the most striking discoveries in the 20th century and was only possible by using type Ia supernovae (SN Iae). Only the thermonuclear explosion of a white dwarf (WD) following the interaction in a binary system can explain the observed features. Several different binary scenarios are discussed including the merger and subsequent explosion of an ultracompact double white dwarf (double degenerate) or an explosion triggered by helium accretion from a helium star donor (double detonation). The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave (GW) detector, which is currently being built by ESA. LISA will be sensitive to measure GWs directly of thousands of Galactic binaries, allowing for multi-messenger studies. The PI proposes to conduct a detailed observational study to identify and classify at least a few hundred SN Ia progenitors and LISA GW sources to 1) derive compact binary space densities and predict rates for different SN Ia formation channels to solve the supernova Ia progenitor problem 2) provide the first observationally derived population of resolvable LISA sources and Galactic LISA foreground sources To achieve this ambitious project the PI will use ongoing and upcoming sky surveys such as ZTF, BlackGEM, Gaia, Vera Rubin Observatory and SDSS-V combined with large-scale multiwavelength surveys. The large number of sky surveys combined with recent developments in data processing, including dense Galactic Plane regions makes this project very timely. The results will calibrate theoretical models for SN Ia, common envelope evolution and will help to find the optimal data analysis methods for LISA so that its mission requirements can be achieved. The PI will successfully lead this project because of his i) profound experience in large-scale sky-surveys, ii) proprietary data access to BlackGEM data and iii) direct involvement in multi-messenger projects for LISA.