The continuous cadence Roman Galactic Bulge survey

TL;DR

This paper proposes a survey strategy using the Nancy Grace Roman Space Telescope to discover and study short-period binaries in the Galactic Bulge, which are key sources for gravitational wave detection and multi-messenger astronomy.

Contribution

It introduces a novel observing strategy targeting the Galactic Bulge to identify and analyze gravitational wave sources and related short-period variables.

Findings

Potential discovery of dozens of new gravitational wave sources.

Identification of exoplanet candidates around white dwarf binaries.

Enhanced understanding of short-period variable populations.

Abstract

Galactic binaries with orbital periods less than 1 hour are strong gravitational wave sources in the mHz regime, ideal for the Laser Interferometer Space Antenna (LISA). At least several hundred, maybe up to a thousand of those binaries are predicted to be sufficiently bright in electromagnetic wavebands to allow detection in both the electromagnetic and the gravitational bands allowing us to perform multi-messenger studies on a statistically significant sample. Theory predicts that a large number of these sources will be located in the Galactic Plane and in particular towards the Galactic Bulge region. Some of these tight binaries may host sub-stellar tertiaries. In this white paper we propose an observing strategy for the Galactic Bulge Time Domain Survey which would use the unique observing capabilities of the Nancy Grace Roman Space telescope to discover and study several 10s of new strong LISA gravitational sources as well as exoplanet candidates around compact white dwarf binaries and other short period variables such as flaring stars, compact pulsators and rotators.