European Pulsar Timing Array

The European Pulsar Timing Array (EPTA) is a European program using radio telescopes to record the timings of a pulsar timing array (PTA). (A PTA is a set of pulsars selected for such monitoring with the intention of detecting gravitational waves through analysis of their exact pulse timing.) The EPTA's data is also passed along to the International Pulsar Timing Array (IPTA) effort. The EPTA uses the telescopes:

• Westerbork Synthesis Radio Telescope (WSRT).
• Effelsberg 100-m Radio Telescope.
• Lovell Telescope.
• Nançay Radio Telescope (NRT).
• Sardinia Radio Telescope (SRT).

EPTA+ refers to a subset of 42 of the pulsars, considered to be a particularly reliable and useful sample, whose timing data has been used in some specific studies.

PTAs as gravitational-wave detectors are sensitive to a different range of frequencies than LIGO's and Virgo's 10-10000 Hz regime: the range for PTAs is microhertz and slower (e.g., nanohertz gravitational waves), the presumed detectable sources being binary SMBHs with orbits in this frequency range.

LEAP (for Large European Array for Pulsars) is an EPTA project to use the five telescopes as a phased array to time the pulsars, the aim being increased collecting area and timing precision.