Science

eLISA/NGO surveys compact stellar-mass binaries and studies the structure of the Milky Way

With eLISA/NGO we will detect stellar-mass binary systems in our galaxy. Most of them will be very compact remnants of common stars, called white dwarfs.

Very soon after activation, eLISA/NGO will detect gravitational wave signals from known nearby binary compact stars. Because of their known positions and periods they serve as “verification binaries” ensuring in particular, predictable eLISA/NGO signals. Signals are also certain to appear from populations of numerous and various remnants in our galaxy, including white dwarfs and neutron stars, which are known to exist from electromagnetic observations.

Extrapolation of known samples predicts that eLISA/NGO will detect several thousand binaries. For hundreds of these, eLISA/NGO will determine the orbital periods, mass parameters and distance, a rich trove of information for detailed mapping of our galaxy.

These discoveries will also shed light on the outcome of the common envelope phase, on the progenitors of type Ia supernovae, and on tidal and non-gravitational influences on orbits associated with the internal physics of the compact remnants themselves.

eLISA/NGO will detect only the brightest and nearest binaries as individual sources; millions of others from across the Galaxy will blend together into a confusion foreground.