Noise analysis in the European Pulsar Timing Array data release 2 and its implications on the gravitational-wave background search

Understand

The European Pulsar Timing Array (EPTA) collaboration has recently released an extended data set for six pulsars (DR2) and reported evidence for a common red noise signal.

• Here we present a noise analysis for each of the six pulsars.
• We consider several types of noise: (i) radio frequency independent, "achromatic", and time-correlated red noise; (ii) variations of dispersion measure and scattering; (iii) system and band noise; and (iv) deterministic signals (other than gravitational waves) that could be present in the PTA data.
• We perform Bayesian model selection to find the optimal combination of noise components for each pulsar.