Observing white dwarfs orbiting massive black holes in the gravitational wave and electro-magnetic window

Understand

We consider a potentially new class of gravitational wave sources consisting of a white dwarf coalescing into a massive black hole in the mass range ~10^4-10^5\msun.

• These sources are of particular interest because the gravitational wave signal produced during the inspiral phase can be detected by the Laser Interferometer Space Antenna (LISA) and is promptly followed, in an extended portion of the black hole and white dwarf mass parameter space, by an electro-magnetic signal generated by the tidal disruption of the star, detectable with X-ray, optical and UV telescopes.
• This class of sources could therefore yield a considerable number of scientific payoffs, that include precise cosmography at low redshift, demographics of black holes in the mass range ~10^4-10^5\Msun, insights into dynamical interactions and populations of white dwarfs in the cores of dwarf galaxies, as well as a new probe into the structure and equation of state of white dwarfs.
• By modelling the gravitational and electromagnetic radiation produced by these events, we find them detectable in both observational windows at a distance ~200 Mpc, and possibly beyond for selected regions of the parameter space.