@article{PetrovSingerCoughlinetal.2022,
  author    = {Petrov, Polina and Singer, Leo P. and Coughlin, Michael W. and Kumar, Vishwesh and Almualla, Mouza and Anand, Shreya and Bulla, Mattia and Dietrich, Tim and Foucart, Francois and Guessoum, Nidhal},
  title     = {Data-driven expectations for electromagnetic counterpart searches based on LIGO/Virgo public alerts},
  series = {The astrophysical journal : an international review of spectroscopy and astronomical physics; part 1},
  volume    = {924},
  journal   = {The astrophysical journal : an international review of spectroscopy and astronomical physics; part 1},
  number    = {2},
  publisher = {Institute of Physics Publ.},
  address   = {London},
  issn      = {1538-4357},
  doi       = {10.3847/1538-4357/ac366d},
  pages     = {10},
  year      = {2022},
  abstract  = {Searches for electromagnetic counterparts of gravitational-wave signals have redoubled since the first detection in 2017 of a binary neutron star merger with a gamma-ray burst, optical/infrared kilonova, and panchromatic afterglow. Yet, one LIGO/Virgo observing run later, there has not yet been a second, secure identification of an electromagnetic counterpart. This is not surprising given that the localization uncertainties of events in LIGO and Virgo's third observing run, O3, were much larger than predicted. We explain this by showing that improvements in data analysis that now allow LIGO/Virgo to detect weaker and hence more poorly localized events have increased the overall number of detections, of which well-localized, gold-plated events make up a smaller proportion overall. We present simulations of the next two LIGO/Virgo/KAGRA observing runs, O4 and O5, that are grounded in the statistics of O3 public alerts. To illustrate the significant impact that the updated predictions can have, we study the follow-up strategy for the Zwicky Transient Facility. Realistic and timely forecasting of gravitational-wave localization accuracy is paramount given the large commitments of telescope time and the need to prioritize which events are followed up. We include a data release of our simulated localizations as a public proposal planning resource for astronomers.},
  language  = {en}
}
@article{HuthPangTewsetal.2022,
  author    = {Huth, Sabrina and Pang, Peter Tsun Ho and Tews, Ingo and Dietrich, Tim and Le F{\`e}vre, Arnaud and Schwenk, Achim and Trautmann, Wolfgang and Agarwal, Kshitij and Bulla, Mattia and Coughlin, Michael W. and Van den Broeck, Chris},
  title     = {Constraining neutron-star matter with microscopic and macroscopic collisions},
  series = {Nature : the international weekly journal of science},
  volume    = {606},
  journal   = {Nature : the international weekly journal of science},
  number    = {7913},
  publisher = {Nature Publ. Group},
  address   = {London [u.a.]},
  issn      = {0028-0836},
  doi       = {10.1038/s41586-022-04750-w},
  pages     = {276 -- 295},
  year      = {2022},
  abstract  = {Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. However, our knowledge about dense matter explored in the cores of neutron stars remains limited. Fortunately, dense matter is not probed only in astrophysical observations, but also in terrestrial heavy-ion collision experiments. Here we use Bayesian inference to combine data from astrophysical multi-messenger observations of neutron stars(1-9) and from heavy-ion collisions of gold nuclei at relativistic energies(10,11) with microscopic nuclear theory calculations(12-17) to improve our understanding of dense matter. We find that the inclusion of heavy-ion collision data indicates an increase in the pressure in dense matter relative to previous analyses, shifting neutron-star radii towards larger values, consistent with recent observations by the Neutron Star Interior Composition Explorer mission(5-8,18). Our findings show that constraints from heavy-ion collision experiments show a remarkable consistency with multi-messenger observations and provide complementary information on nuclear matter at intermediate densities. This work combines nuclear theory, nuclear experiment and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars.},
  language  = {en}
}
@article{KunertPangTewsetal.2022,
  author    = {Kunert, Nina and Pang, Peter T. H. and Tews, Ingo and Coughlin, Michael W. and Dietrich, Tim},
  title     = {Quantifying modeling uncertainties when combining multiple gravitational-wave detections from binary neutron star sources},
  series = {Physical review D},
  volume    = {105},
  journal   = {Physical review D},
  number    = {6},
  publisher = {American Physical Society},
  address   = {College Park},
  issn      = {2470-0010},
  doi       = {10.1103/PhysRevD.105.L061301},
  pages     = {7},
  year      = {2022},
  abstract  = {With the increasing sensitivity of gravitational-wave detectors, we expect to observe multiple binary neutron-star systems through gravitational waves in the near future. The combined analysis of these gravitational-wave signals offers the possibility to constrain the neutron-star radius and the equation of state of dense nuclear matter with unprecedented accuracy. However, it is crucial to ensure that uncertainties inherent in the gravitational-wave models will not lead to systematic biases when information from multiple detections is combined. To quantify waveform systematics, we perform an extensive simulation campaign of binary neutron-star sources and analyze them with a set of four different waveform models. For our analysis with 38 simulations, we find that statistical uncertainties in the neutron-star radius decrease to 1250 m (2\% at 90\% credible interval) but that systematic differences between currently employed waveform models can be twice as large. Hence, it will be essential to ensure that systematic biases will not become dominant in inferences of the neutron-star equation of state when capitalizing on future developments.},
  language  = {en}
}
@misc{BullaCoughlinDhawanetal.2022,
  author    = {Bulla, Mattia and Coughlin, Michael W. and Dhawan, Suhail and Dietrich, Tim},
  title     = {Multi-messenger constraints on the Hubble constant through combination of gravitational waves, gamma-ray bursts and kilonovae from neutron star mergers},
  series = {Universe : open access journal},
  volume    = {8},
  journal   = {Universe : open access journal},
  number    = {5},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2218-1997},
  doi       = {10.3390/universe8050289},
  pages     = {21},
  year      = {2022},
  abstract  = {The simultaneous detection of gravitational waves and light from the binary neutron star merger GW170817 led to independent measurements of distance and redshift, providing a direct estimate of the Hubble constant H-0 that does not rely on a cosmic distance ladder, nor assumes a specific cosmological model. By using gravitational waves as "standard sirens", this approach holds promise to arbitrate the existing tension between the H-0 value inferred from the cosmic microwave background and those obtained from local measurements. However, the known degeneracy in the gravitational-wave analysis between distance and inclination of the source led to a H-0 value from GW170817 that was not precise enough to resolve the existing tension. In this review, we summarize recent works exploiting the viewing-angle dependence of the electromagnetic signal, namely the associated short gamma-ray burst and kilonova, to constrain the system inclination and improve on H-0. We outline the key ingredients of the different methods, summarize the results obtained in the aftermath of GW170817 and discuss the possible systematics introduced by each of these methods.},
  language  = {en}
}