Practical approaches to analyzing PTA data: Cosmic strings with six pulsars

Understand

We search for a stochastic gravitational wave background (SGWB) generated by a network of cosmic strings using six millisecond pulsars from Data Release 2 (DR2) of the European Pulsar Timing Array (EPTA).

• We perform a Bayesian analysis considering two models for the network of cosmic string loops, and compare it to a simple power-law model which is expected from the population of supermassive black hole binaries.
• Our main strong assumption is that the previously reported common red noise process is a SGWB.
• We find that the one-parameter cosmic string model is slightly favored over a power-law model thanks to its simplicity.