Observation of Gravitational Waves from the Coalescence of a $2.5\text{-}4.5M_{\odot }$ Compact Object and a Neutron Star

Abstract

We report the observation of a coalescing compact binary with component masses $2.5\text{-}4.5M_{\odot }$ and $1.2\text{-}2.0M_{\odot }$ (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO-Virgo-KAGRA detector network on 2023 May 29 by the LIGO Livingston Observatory. The primary component of the source has a mass less than $5M_{\odot }$ at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find the most probable interpretation of the source to be the coalescence of a neutron star with a black hole that has a mass between the most massive neutron stars and the least massive black holes observed in the Galaxy. We provisionally estimate a merger rate density of $55_{-47}^{+127}{\text{Gpc}}^{-3}{\text{yr}}^{-1}$ for compact binary coalescences with properties similar to the source of GW230529_181500; assuming that the source is a neutron star-black hole merger, GW230529_181500-like sources constitute about 60% of the total merger rate inferred for neutron star-black hole coalescences. The discovery of this system implies an increase in the expected rate of neutron star-black hole mergers with electromagnetic counterparts and provides further evidence for compact objects existing within the purported lower mass gap.

45 pages (10 pages author list, 13 pages main text, 1 page acknowledgements, 13 pages appendices, 8 pages bibliography), 17 figures, 16 tables. Update to match version published in The Astrophysical Journal Letters. Data products available from https://zenodo.org/records/10845779

References in corpus (141)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• A Massive Pulsar in a Compact Relativistic Binary
• Multi-messenger Observations of a Binary Neutron Star Merger
• Advanced LIGO
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• GW190814: Gravitational Waves from the Coalescence of a 23 M${}_{\odot }$ Black Hole with a 2.6 M${}_{\odot }$ Compact Object
• PSR J0030+0451 Mass and Radius from NICER Data and Implications for the Properties of Neutron Star Matter
• GWTC-3: Compact Binary Coalescences Observed by LIGO and Virgo During the Second Part of the Third Observing Run
• A NICER View of PSR J0030+0451: Millisecond Pulsar Parameter Estimation
• GW190425: Observation of a Compact Binary Coalescence with Total Mass $\sim 3.4M_{\odot }$
• Constraining neutron star tidal Love numbers with gravitational wave detectors
• A NICER View of the Massive Pulsar PSR J0740+6620 Informed by Radio Timing and XMM-Newton Spectroscopy
• Refined Mass and Geometric Measurements of the High-Mass PSR J0740+6620
• Relativistic theory of tidal Love numbers
• Observation of gravitational waves from two neutron star-black hole coalescences
• An improved effective-one-body model of spinning, nonprecessing binary black holes for the era of gravitational-wave astrophysics with advanced detectors
• Computationally efficient models for the dominant and sub-dominant harmonic modes of precessing binary black holes
• PSR J0952-0607: The Fastest and Heaviest Known Galactic Neutron Star
• Bayesian inference for compact binary coalescences with BILBY: Validation and application to the first LIGO--Virgo gravitational-wave transient catalogue
• BayesWave: Bayesian Inference for Gravitational Wave Bursts and Instrument Glitches
• Towards models of gravitational waveforms from generic binaries II: Modelling precession effects with a single effective precession parameter
• Sensitivity and Performance of the Advanced LIGO Detectors in the Third Observing Run
• Illuminating Black Hole Binary Formation Channels with Spins in Advanced LIGO
• Nonparametric constraints on neutron star matter with existing and upcoming gravitational wave and pulsar observations
• IMRPhenomXHM: A multi-mode frequency-domain model for the gravitational wave signal from non-precessing black-hole binaries
• Analysis of spin precession in binary black hole systems including quadrupole-monopole interaction
• Setting the cornerstone for the IMRPhenomX family of models for gravitational waves from compact binaries: The dominant harmonic for non-precessing quasi-circular black holes
• BayesLine: Bayesian Inference for Spectral Estimation of Gravitational Wave Detector Noise
• Improving the NRTidal model for binary neutron star systems
• Black Hole-Neutron Star Mergers: Disk Mass Predictions
• 4-OGC: Catalog of gravitational waves from compact-binary mergers
• LIGO Detector Characterization in the Second and Third Observing Runs
• An updated mass-radius analysis of the 2017-2018 NICER data set of PSR J0030+0451
• Impact of the PSR J0740+6620 radius constraint on the properties of high-density matter
• Massively parallel Bayesian inference for transient gravitational-wave astronomy
• Spectral Representations of Neutron-Star Equations of State
• Non-parametric inference of the neutron star equation of state from gravitational wave observations
• Nonparametric Inference of Neutron Star Composition, Equation of State, and Maximum Mass with GW170817
• Search for gravitational lensing signatures in LIGO-Virgo binary black hole events
• The Explosion of Helium Stars Evolved With Mass Loss
• Frequency-Dependent Squeezing for Advanced LIGO
• Relativistic simulations of black hole-neutron star coalescence: the jet emerges
• Tidal Deformation and Dissipation of Rotating Black Holes
• A lower bound on the maximum mass if the secondary in GW190814 was once a rapidly spinning neutron star
• Neutron star-black hole mergers with a nuclear equation of state and neutrino cooling: Dependence in the binary parameters
• The mass distribution of Galactic double neutron stars
• SEOBNRv5PHM: Next generation of accurate and efficient multipolar precessing-spin effective-one-body waveforms for binary black holes
• Probing the non-linear structure of general relativity with black hole binaries
• The BayesWave analysis pipeline in the era of gravitational wave observations
• Laying the foundation of the effective-one-body waveform models SEOBNRv5: improved accuracy and efficiency for spinning non-precessing binary black holes
• Impact of Massive Binary Star and Cosmic Evolution on Gravitational Wave Observations I: Black Hole-Neutron Star Mergers
• The MBTA Pipeline for Detecting Compact Binary Coalescences in the Third LIGO-Virgo Observing Run
• On the Rate of Neutron Star Binary Mergers from Globular Clusters
• Estimates for Disk and Ejecta Masses Produced in Compact Binary Mergers
• Mass-gap Mergers in Active Galactic Nuclei
• Exploring the Lower Mass Gap and Unequal Mass Regime in Compact Binary Evolution
• Accelerated gravitational-wave parameter estimation with reduced order modeling
• Frequency domain reduced order model of aligned-spin effective-one-body waveforms with higher-order modes
• Simple recipes for compact remnant masses and natal kicks
• Constraining the masses of microlensing black holes and the mass gap with Gaia DR2
• Extending the PyCBC search for gravitational waves from compact binary mergers to a global network
• On the maximum mass of neutron stars and GW190814
• The Radius of PSR J0740+6620 from NICER with NICER Background Estimates
• A Unicorn in Monoceros: the $3M_{\odot }$ dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate
• Accuracy Requirements for Empirically-Measured Selection Functions
• Modeling the gravitational wave signature of neutron star black hole coalescences: PhenomNSBH
• Parallelized Inference for Gravitational-Wave Astronomy
• Reducing Scattered Light in LIGO's Third Observing Run
• PESummary: the code agnostic Parameter Estimation Summary page builder
• Fast evaluation of multi-detector consistency for real-time gravitational wave searches
• Omicron: a tool to characterize transient noise in gravitational-wave detectors
• Realtime search for compact binary mergers in Advanced LIGO and Virgo's third observing run using PyCBC Live
• Model-independent inference on compact-binary observations
• Review of the Advanced LIGO gravitational wave observatories leading to observing run four
• A pulsar in a binary with a compact object in the mass gap between neutron stars and black holes
• An aligned-spin neutron-star--black-hole waveform model based on the effective-one-body approach and numerical-relativity simulations
• The Advanced LIGO Photon Calibrators
• The impact of fallback on the compact remnants and chemical yields of core-collapse supernovae
• Dynamics of black hole - neutron star binaries in young star clusters
• Tests of General Relativity with Gravitational-Wave Observations using a Flexible--Theory-Independent Method
• Higher order gravitational-wave modes with likelihood reweighting
• Picky Partners: The Pairing of Component Masses in Binary Black Hole Mergers
• Enhancing the SEOBNRv5 effective-one-body waveform model with second-order gravitational self-force fluxes
• PhenomXO4a: a phenomenological gravitational-wave model for precessing black-hole binaries with higher multipoles and asymmetries
• Black Hole Formation in the Lower Mass Gap through Mergers and Accretion in AGN Disks
• Accelerating parameter estimation of gravitational waves from compact binary coalescence using adaptive frequency resolutions
• On the formation of GW190814
• Environmental Influences on the LIGO Gravitational Wave Detectors during the 6th Science Run
• Discriminating between Neutron Stars and Black Holes with Imperfect Knowledge of the Maximum Neutron Star Mass
• Environmental Noise in Advanced LIGO Detectors
• Does Matter Matter? Using the mass distribution to distinguish neutron stars and black holes
• Modelling Neutron Star-Black Hole Binaries: Future Pulsar Surveys and Gravitational Wave Detectors
• Merging Black Holes in the Low-mass and High-mass Gaps from 2+2 Quadruple Systems
• Gravitational waveforms from SpEC simulations : neutron star-neutron star and low-mass black hole-neutron star binaries
• Rapid Parameter Estimation of Gravitational Waves from Binary Neutron Star Coalescence using Focused Reduced Order Quadrature
• Neutron stars versus black holes: probing the mass gap with LIGO/Virgo
• A self-consistent method to estimate the rate of compact binary coalescences with a Poisson mixture model
• New and Robust Gravitational-Waveform Model for High-Mass-Ratio Binary Neutron Star Systems with Dynamical Tidal Effects
• Black holes in the low mass gap: Implications for gravitational wave observations
• Dissecting the properties of neutron star - black hole mergers originating in dense star clusters
• Improved ranking statistics of the GstLAL inspiral search for compact binary coalescences
• Non-parametric inference of the population of compact binaries from gravitational wave observations using binned Gaussian processes
• Estimating the maximum gravitational mass of nonrotating neutron stars from the GW170817/GRB 170817A/AT2017gfo observation
• A Machine Learning Based Source Property Inference for Compact Binary Mergers
• Point absorbers in Advanced LIGO
• Black holes, disks and jets following binary mergers and stellar collapse: The narrow range of EM luminosities and accretion rates
• The role of supernova convection for the lower mass gap in the isolated binary formation of gravitational wave sources
• A Population-Informed Mass Estimate for Pulsar J0740+6620
• Discovering gravitationally lensed gravitational waves: predicted rates, candidate selection, and localization with the Vera Rubin Observatory
• Lensed or not lensed: Determining lensing magnifications for binary neutron star mergers from a single detection
• Accelerating the evaluation of inspiral-merger-ringdown waveforms with adapted grids
• Role of the symmetry energy and the neutron-matter stiffness on the tidal deformability of a neutron star with unified equations of state
• Gravitational-wave inference in the catalog era: evolving priors and marginal events
• Population properties and multimessenger prospects of neutron star-black hole mergers following GWTC-3
• Dynamic Normalization for Compact Binary Coalescence Searches in Non-Stationary Noise
• Comment on "A non-interacting low-mass black hole -- giant star binary system"
• Populating the Black Hole Mass Gaps In Stellar Clusters: General Relations and Upper Limits
• Probing Extremal Gravitational-Wave Events with Coarse-Grained Likelihoods
• Atmospheric Effects on Neutron Star Parameter Constraints with NICER
• Tossing Black Hole Spin Axes
• Numerical-Relativity-Informed Effective-One-Body model for Black-Hole-Neutron-Star Mergers with Higher Modes and Spin Precession
• Template bank for compact binary mergers in the fourth observing run of Advanced LIGO, Advanced Virgo, and KAGRA
• Statistical and systematic uncertainties in extracting the source properties of neutron star - black hole binaries with gravitational waves
• Dynamical formation of the GW190814 merger
• Fallback supernova assembly of heavy binary neutron stars and light black hole-neutron star pairs and the common stellar ancestry of GW190425 and GW200115
• Fortifying gravitational-wave tests of general relativity against astrophysical assumptions
• How important is secular evolution for black hole and neutron star mergers in 2+2 and 3+1 quadruple-star systems?
• Response to Comment on "A Non-Interacting Low-Mass Black Hole -- Giant Star Binary System"
• Explodability fluctuations of massive stellar cores enable asymmetric compact object mergers such as GW190814
• The heavier the better: how to constrain mass ratios and spins of high-mass neutron-star mergers
• On the gravitational lensing interpretation of three gravitational wave detections in the mass gap by LIGO and Virgo
• The relative contribution to heavy metals production from binary neutron star mergers and neutron star-black hole mergers
• Incorporating information from LIGO data quality streams into the PyCBC search for gravitational waves
• An observational upper limit on the rate of gamma-ray bursts with neutron star-black hole merger progenitors
• Nuclear physics with gravitational waves from neutron stars disrupted by black holes
• Astrophysical Source Classification and Distance Estimation for PyCBC Live
• Automated Evaluation of Environmental Coupling for Advanced LIGO Gravitational Wave Detections
• Rapid Hierarchical Inference of Neutron Star Equation of State from multiple Gravitational Wave Observations of Binary Neutron Star Coalescences

Cited by in corpus (101)

• Advanced LIGO detector performance in the fourth observing run
• The Science of the Einstein Telescope
• GWTC-4.0: Updating the Gravitational-Wave Transient Catalog with Observations from the First Part of the Fourth LIGO-Virgo-KAGRA Observing Run
• LIGO Detector Characterization in the first half of the fourth Observing run
• Inspiral-merger-ringdown waveforms in Einstein-scalar-Gauss-Bonnet gravity within the effective-one-body formalism
• Neutron stars and the dense matter equation of state: from microscopic theory to macroscopic observations
• GW241011 and GW241110: Exploring Binary Formation and Fundamental Physics with Asymmetric, High-Spin Black Hole Coalescence
• Systematic Biases in Estimating the Properties of Black Holes Due to Inaccurate Gravitational-Wave Models
• Unequal-mass, highly-spinning binary black hole mergers in the stable mass transfer formation channel
• DESI Dark Energy Time Evolution is Recovered by Cosmologically Coupled Black Holes
• Orbital eccentricity in a neutron star - black hole merger
• Quasi-Normal Modes of Loop Quantum Black Holes Formed from Gravitational Collapse
• Eccentricity signatures in LIGO-Virgo-KAGRA's BNS and NSBH binaries
• New search pipeline for gravitational waves with higher-order modes using mode-by-mode filtering
• Search for continuous gravitational waves from known pulsars in the first part of the fourth LIGO-Virgo-KAGRA observing run
• GW230529_181500: A Potential Primordial Binary Black Hole Merger in the Mass Gap
• The interplay of astrophysics and nuclear physics in determining the properties of neutron stars
• Multi-messenger Gravitational Lensing
• Pseudospectrum of rotating analog black holes
• Parametrized spin-precessing inspiral-merger-ringdown waveform model for tests of general relativity
• Probing fundamental physics with Extreme Mass Ratio Inspirals: a full Bayesian inference for scalar charge
• Lower-mass-gap Black Holes in Dense Star Clusters
• The impact of dark matter on tidal signatures in neutron star mergers with Einstein Telescope
• Search for gravitational waves emitted from SN 2023ixf
• Possible binary neutron star merger history of the primary of GW230529
• First eccentric inspiral-merger-ringdown analysis of neutron star-black hole mergers
• Orbital Eccentricity and Spin-Orbit Misalignment Are Evidence that Neutron Star-Black Hole Mergers Form through Triple Star Evolution
• Formation of GW230529 from Isolated Binary Evolution
• Improved parametrized test of general relativity using the IMRPhenomX waveform family: Including higher harmonics and precession
• Bayesian inferences on covariant density functionals from multimessenger astrophysical data: Nucleonic models
• Probe and Prejudice: Classification of compact objects and model comparison using EOS knowledge
• Probing the Unstable Spectrum of Schwarzschild-like Black Holes
• Kilonova constraints for the LIGO/Virgo/KAGRA neutron star merger candidate S250206dm: GW-MMADS observations
• AsterX: a new open-source GPU-accelerated GRMHD code for dynamical spacetimes
• Phenomenological model of gravitational self-force enhanced tides in inspiralling binary neutron stars
• Multi-spectral Sirens: Gravitational-wave Cosmology with (Multi-) Sub-populations of Binary Black Holes
• The more accurately the metal-dependent star formation rate is modeled, the larger the predicted excess of binary black hole mergers
• What is the nature of GW230529? An exploration of the gravitational lensing hypothesis
• Black hole pulsars and monster shocks as outcomes of black hole--neutron star mergers
• Confronting general relativity with principal component analysis: Simulations and results from GWTC-3 events
• Tests of General Relativity with GW230529: a neutron star merging with a lower mass-gap compact object
• Stable Case BB/BC Mass Transfer to Form GW190425-like Massive Binary Neutron Star Mergers
• Bayesian Search of Massive Scalar Fields from LIGO-Virgo-KAGRA Binaries
• Validating Sequential Monte Carlo for Gravitational-Wave Inference
• Modeling matter(s) in SEOBNRv5THM: Generating fast and accurate effective-one-body waveforms for spin-aligned binary neutron stars
• New approach to template banks of gravitational waves with higher harmonics: Reducing matched-filtering cost by over an order of magnitude
• Origin of Black Hole Spin in Lower-Mass-Gap Black Hole-Neutron Star Binaries
• Waging a Campaign: Results from an Injection-Recovery Study involving 35 numerical Relativity Simulations and three Waveform Models
• Multi-messenger observations in the Einstein Telescope era: binary neutron star and black hole - neutron star mergers
• Late-time non-thermal emission from mildly relativistic tidal ejecta of compact objects merger
• Direct nonparametric multimessenger constraints on the equation of state of cold dense nuclear matter
• A complete waveform comparison of post-Newtonian and numerical relativity in eccentric orbits
• Wolf-Rayet -- compact object binaries as progenitors of binary compact objects
• Verification of the Black Hole Area Law with GW230814
• Confronting recent light compact star observations with color-flavor locked quark matter
• Apparently ultra-long period radio sources from self-lensed pulsar-black hole binaries
• Toward a realistic Buchdahl limit in f(R) theories of gravity
• Stellar-Mass Black Holes
• Testing modified gravity with the eccentric neutron star--black hole merger GW200105
• Neutron Star with Dark Matter Admixture: A Candidate for Bridging the Mass Gap
• Black hole spectroscopy of collapsing and merging neutron stars
• Insights into Binary Neutron Star Merger Simulations: A Multi-Code Comparison
• Black Hole-Neutron Star Binaries near Neutron Star Disruption Limit in the Mass Regime of Event GW230529
• Inferring jet physics from neutron star - black hole mergers with gravitational waves
• Shared Properties of Merger-driven Long-duration Gamma-Ray Bursts
• Ten years of extreme gravity tests of general theory of relativity with gravitational-wave observations
• Detection probability of light compact binary mergers in future observing runs of the current ground-based gravitational wave detector network
• Challenges in Forming Millisecond Pulsar-Black Holes from Isolated Binaries
• Equation of State of Decompressed Quark Matter, and Observational Signatures of Quark-Star Mergers
• Hierarchical searches for subsolar-mass binaries and the third-generation gravitational wave detector era
• Mass function of stellar black holes as revealed by the LIGO-Virgo-KAGRA observations
• Modeling of optical scattering from topographic surface measurements of high-quality mirrors
• Constraining scalar-tensor theories from higher harmonics with GW230529
• Neutron stars more compact than black holes as a probe of strong-field gravity
• Listening Across the Cosmic Time: Standard Sirens from Ground- and Space-Based Missions in the Next Decade
• Black Hole - Neutron Star and Binary Neutron Star Mergers from Population III and II stars
• Binary black holes in the heat of merger
• Detectability and Parameter Estimation for Einstein Telescope Configurations with GWJulia
• Characterizing Compact-object Binaries in the Lower Mass Gap with Gravitational Waves
• Can Big Black Holes Merge with the Smallest Black Holes?
• Challenging a binary neutron star merger interpretation of GW230529
• Bayesian Framework to Follow-up Continuous Gravitational Wave Candidates from Deep Surveys
• Observational bounds on Dark Matter Admixed Neutron Stars from Gravitational Wave Data
• Neural Post-Einsteinian Test of General Relativity with the Third Gravitational-Wave Transient Catalog
• Illuminating the Mass Gap Through Deep Optical Constraint on a Neutron Star Merger Candidate S250206dm
• Neutron stars more compact than black holes in quasi-topological gravity: Equilibrium configurations and radial stability
• Astrophysical constraints on neutron star $f$-modes with a nonparametric equation of state representation
• Search for planetary-mass ultra-compact binaries using data from the first part of the LIGO--Virgo--KAGRA fourth observing run
• Systematic bias due to eccentricity in parameter estimation for merging binary neutron stars : Spinning case
• Enhancing online estimation of CBC parameters with the low-latency MBTA analysis
• Vanishing Compactness Gap and Fermionic Compact Dark Matter in Hořava-Lifshitz Gravity
• Constraints on the VHE counterpart of two binary black hole mergers observed by the MAGIC and CTAO LST-1 telescopes
• Inferring host environment properties and gravitational-wave decay time from the eccentricity measurement of dynamically captured binaries
• Narrowband searches for continuous gravitational waves from known pulsars in the first two parts of the fourth LIGO--Virgo--KAGRA observing run
• Gravitational-wave astronomy requires population-informed parameter estimation
• Implications of low neutron star merger rates for gamma-ray bursts, r-process production and Galactic double neutron stars
• labrador: A domain-optimized machine-learning tool for gravitational wave inference
• Where are Gaia's small black holes?
• Comparing a Compact-Binary Mass-Shell Model with Select Observed Gravitational Waves
• A User-Friendly Python Interface for the Numerical Relativity Code AMSS-NCKU
• Constraining Scalar Charge in Neutron Stars through Gravitational Wave Signals from NSBH Mergers