The data for "The NANOGrav 15 yr Data Set: Targeted Searches for Supermassive Black Hole Binaries"

For a full author list, see the companion publication: Agarwal et al 2025 (arXiv/2508.16534)

This repository contains posterior samples, Hellings-Downs weight factors, electromagnetic priors, and python scripts for targeted searches conducted on the NANOGrav 15 year dataset, corresponding to the paper "The NANOGrav 15-Year Data Set: Targeted Searches for Supermassive Black Hole Binaries" (arXiv/2508.16534).

• The posterior samples for each target were obtained using the enterprise and PTMCMCSampler python packages assuming a common uncorrelated red noise (CURN), and are stored as condensed HDF5 files compatible with the la_forge python package for MCMC post-processing.
• Alongside each target's HDF5 file are 2 text files containing 1) log weight factors which can be applied to the posterior samples to obtain posterior distributions assuming an HD-correlated GWB instead of CURN, and 2) indices matching each weight factor to the sample from the original chain.
• The included codebase may be used to reproduce analysis results. This features electromagnetic prior information on each target, pulsar distances, python scripts used to carry out the searches, and example notebooks for analysis.
• The NANOGrav 15 yr dataset on which the searches were performed is found in the separate repository (DOI: 10.5281/zenodo.16051178).