2007ApJ...655.1025K

Both detached, inspiraling and semidetached, mass-transferring double white dwarf (DWD) binary systems are expected to be important sources for the proposed space-based gravitational wave detector, LISA. The mass-radius relationship of individual white dwarf stars, in combination with the constraints imposed by Roche geometries, permits us to identify population boundaries for DWD systems in LISA's ``absolute'' amplitude-frequency diagram. With five key population boundaries in place, we are able to identify four principal population subdomains, including one subdomain that identifies where progenitors of Type Ia supernovae will reside. Given one full year of uninterrupted operation, LISA should be able to measure the rate at which the gravitational wave frequency f and, hence, the orbital period is changing in the highest frequency subpopulation of our Galaxy's DWD systems. We provide a formula by which the distance to each DWD system in this subpopulation can be determined; in addition, we show how the masses of the individual white dwarf stars in mass-transferring systems may be calculated.