Thomas Kupfer
The Systematic Search for Ultracompact Binaries Using Optical Time Domain Surveys
March 22, 2018
When: March 22, 2018 3:30PM
Thomas Kupfer
California Institute of Technology
Ultracompact binaries are a rare class of binary systems with ultrashort periods (detached or semidetached), consisting of a He-star/white dwarf (WD) primary and a He-star, WD or neutron star secondary. The study of ultracompact binaries are important to our understanding of such diverse areas as supernova Ia progenitors, binary evolution in general and some of them are predicted to be the strongest gravitational wave sources in the LISA band. However, the number of known systems is still limited. In this talk I present some highlights of several new detached systems which we discovered as part of a search for hot (ultra-)compact systems with the Palomar Transient Factory (PTF) data based on a color selected sample from PanSTARRS. The Zwicky Transient Facility is the next generation of optical time-domain surveys building up on the experience of PTF but 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. Additionally, I am lead investigator of a high-cadence survey covering the full inner Galactic Plane visible from the northern hemisphere as part of ZTF. In this talk I will give an overview of the survey design and our effort to identify ultracompact systems in a systematic way and discuss the expected numbers of ultracompact systems from this survey.