Potential Gravitational-wave and Gamma-ray Multi-messenger Candidate from Oct. 30, 2015

**Alexander H. Nitz^1,2, Alex B. Nielsen^1,2, Collin Capano^1,2

<sub>1. Albert-Einstein-Institut, Max-Planck-Institut for Gravitationsphysik, D-30167 Hannover, Germany
2. Leibniz Universitat Hannover, D-30167 Hannover, Germany</sub>

Read the associated paper on Arxiv

Abstract

We present a search for binary neutron star mergers during the first observing run of Advanced LIGO that produce both gravitational-wave and gamma-ray emission similar to GW170817 and GRB 170817A. We introduce a method to detect sources that do not produce significant gravitational-wave or gamma-ray burst candidates individually. Searches of this type can increase by 70% the detections of joint gravitational-wave and gamma-ray signals. We find one possible candidate at a false alarm rate of 1 in 13 years. If confirmed, this candidate would correspond to a merger at 187+99 −87 Mpc with source-frame chirp mass of 1.30+0.02−0.03 Mpc. If we assume the viewing angle must be < 30◦ to be observed by Fermi-GBM, our estimate of the distance would become 224+88 −78 Mpc. By comparing the rate of binary neutron star mergers to our search-estimated rate of false alarms, we estimate that there is a 1 in 4 chance this candidate is astrophysical in origin.

Reading the 1-OGC 151030 posterior samples

We have provided the posterior samples from the parameter estimation analysis of 1-OGC 151030 as an HDF file, posterior.hdf. See How to read the posterior file for details on how to read this file.

We have also provided the configuration file inference.ini used for the parameter esimtation analysis (which specifies the prior used), and the script used to run pycbc_inference to generate the results (run.sh). These may be found in the scripts directory.

License and Citation

We encourage use of these data in derivative works. If you use the material provided here, please cite the paper using the reference:

@article{Nitz:2019bxt,
      author         = "Nitz, Alexander H. and Nielsen, Alex B. and Capano,
                        Collin D.",
      title          = "{Potential Gravitational-wave and Gamma-ray
                        Multi-messenger Candidate from Oct. 30, 2015}",
      journal        = "Astrophys. J. Lett.",
      volume         = "876",
      year           = "2019",
      pages          = "L4",
      doi            = "10.3847/2041-8213/ab18a1",
      eprint         = "1902.09496",
      archivePrefix  = "arXiv",
      primaryClass   = "astro-ph.HE",
      SLACcitation   = "%%CITATION = ARXIV:1902.09496;%%"
}