Sensitivity of pulsar timing observations to low-frequency noise and search for the Gravitational Wave Background using Pulsar Timing Array.

Timing of millisecond and binary pulsars gives us an unique possibility to search for the stochastic gravitational wave background (GWB). Low-frequency GWB will cause fluctuations in the Times of Arrival (TOA) of the observed pulsars' pulses. Such fluctuations will manifest themselves as a low-frequency correlated noise in the TOA residuals (timing noise). Analysis of the correlations between TOA residuals in the ensemble of pulsars (further referred as Pulsar Timing Array - PTA) gives us one of the most effective method to search for GWB up to date. In this work we analyze how much the standard timing data processing procedure may influence the efficiency of this method.