New developments in space-based gravitational wave astronomy

Monday, August 1, 2011

For almost two decades now, ESA and NASA have studied the LISA mission for the observation of low-frequency gravitational waves as an equally shared partnership of the two agencies.

ESA has recently changed the guidelines for large (”L-class”) missions in the Cosmic Vision framework to require European-only funding, because NASA was financially unable to proceed on the timescale of the launch of the first L-class mission (”L1”) in ESA’s Cosmic Vision Programme.

A search for a European-led variant of LISA that could be launched by 2022 was begun.

After studying several configurations, a new baseline for transfer, orbit and layout has been identified that will be refined in the coming month with the help of European industry. The new baseline employs less costly orbits, and simplifies the design of LISA by reducing the distance between the satellites and employing four rather than six laser links. This considerably reduces the mass and cost, while retaining much of the original science, in part because of new approaches to data analysis.

The European Science Team and a Science Task Force, composed of members of the gravitational wave and astrophysics communities in both Europe and the US, have assessed the scientific validity of the new LISA baseline for the fields of physics, astrophysics and cosmology and have shown that the new configuration should detect thousands of galactic binaries, tens of (super)massive black hole mergers out to a redshift of z=10 and tens of extreme mass ratio inspirals out to a redshift of 1.5 during its two year mission. The investigation of fundamental physics and cosmology tests will continue over the next few months, until we have a finalized mission proposal by the fall of 2011. The preliminary results of this investigation are looking promising.

This announcement is not an official statement of ESA or NASA.

Karsten Danzmann
(Formerly co-chair of the LISA International Science Team)