2018-02-16 Thomas Kupfer (Caltech)
Ultracompact binaries are a rare class of binary systems with periods below 60 min (detached or semidetached), consisting of a neutron star (NS)/white dwarf (WD) primary and a He-star/WD/NS secondary. The study of ultracompact binaries and their subsequent mergers are important to our understanding of such diverse areas as supernova Ia progenitors, production of r-process elements, binary evolution and they are predicted to be the strong gravitational wave sources in the LISA and LIGO-Virgo band.
The Zwicky Transient Facility is the next generation of optical synoptic surveys utilizing the entire focal plane of 47 sq.deg. of the 1.2m telescope on Mount Palomar. The field-of-view allows us to cover the entire visible sky in one night revisiting fields on timescales of a few hours and providing hundreds of visits per field each year. Part of the survey will be a public 3-4 night cadence all sky survey as well as a nightly sweep of the Galactic Plane. Science operations is expected to start early 2018. In this talk I will give an overview of the survey design and our effort to identify the optical counterpart to NS mergers triggered by LIGO-Virgo as early as possible. I am lead investigator of an approved high-cadence survey covering the full inner Plane visible from the northern hemisphere as part of ZTF. We will obtain 2-3 hr continuous lightcurves of each field with a cadence of 40 sec starting summer 2018 to identify the Galactic population of ultracompact binaries. I will give an overview of the survey as well as discuss the expected numbers of ultracompact LISA sources from this survey.