The International Pulsar Timing Array: Second data release

Arecibo Observatory scientist Dr. Benetge Perera lead a recent publication detailing the second data release of the International Pulsar Timing Array in the Monthly Notices of the Royal Astronomical Society. The release included high precision timing data of 65 millisecond pulsars, reported improvements to their timing precision, and created the most up-to-date public data release that facilitates searches for low-frequency gravitational waves and other pulsar science. Gravitational waves produced from inspiraling supermassive black hole binaries and other low frequency (nanoHz to microHz) signals affect the timing of pulsars in a correlated manner. Timing observations of pulsars - and in particular, the rotationally-stable millisecond pulsars - are therefore ideal tools to use in the search for and characterization of gravitational waves. Millisecond pulsars are sensitive enough to measure small-scale perturbations caused by low-frequency gravitational waves, lead author Dr. Perera said. These perturbations are tiny and therefore we need sub-microsecond timing precision in our pulsars to detect these GWs. IPTA experiment can achieve this required timing precision in GW detection.

These perturbations are tiny and therefore we need sub-microsecond timing precision in our pulsars to detect these GWs. IPTA experiment can achieve this required timing precision in GW detection. - Dr. Ben Perera

These perturbations are tiny and therefore we need sub-microsecond timing precision in our pulsars to detect these GWs. IPTA experiment can achieve this required timing precision in GW detection. - Dr. Ben Perera With the goal of improving the timing precision of pulsar observations and therefore sensitivity to gravitational waves, the International Pulsar Timing Array (IPTA) combines data from three regional consortia: the European Pulsar Timing Array, the North Americn Nanohertz Observatory for Gravitational Waves, and the Parkes Pulsar Timing Array. The individual data sets contributing to the IPTA data release come from a number of radio telescopes stationed across the globe, including the Arecibo Observatory. This work expanded upon the previous IPTA data release, which was not only used to place limits on the strain amplitudes for gravitational waves and on the stochastic gravitational wave background, but was also used for mass estimates of Main Belt asteroids within our own Solar System. The recent publication describes the importance of properly removing the noise properties of pulsars, and provides two versions of the data sets that reflect differences in the modeling of the dispersion measure information. Dr. Perera summarized that this new data release provides a better sky coverage that includes more pulsars, and better time baselines, compared to the previous release. Therefore, IPTA dr2 is the most complete millisecond pulsar data set produced so far for GW studies.

As with studies enabled by its predecessor, the IPTA second data release is expected to further improve pulsar timing measurements, constrain the gravitational wave background by accounting for Solar System effects, and searching for gravitational wave memory. The authors note that the data may also be used to search for individually-resolvable supermassive black hole binary systems and constraining beyond-General-Relativity gravitational wave polarization states. The data release may also impact other synergistic sciences, such as providing a probe of ultralight scalar-field dark matter; improving the characterization of radio-frequency dependent delay processes induced by the ionized interstellar medium and solar wind; studying select solar system objects; and synthesizing a pulsar-based time standard.

Keywords: arecibo, pulsars, observatory timing, black, hole, perera, puerto rico, array, gravitational, waves, asteroids, Parkes