The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VII. Properties of the Host Galaxy and Constraints on the Merger Timescale

Abstract

We present the properties of NGC 4993, the host galaxy of GW170817, the first gravitational wave (GW) event from the merger of a binary neutron star (BNS) system and the first with an electromagnetic (EM) counterpart. We use both archival photometry and new optical/near-IR imaging and spectroscopy, together with stellar population synthesis models to infer the global properties of the host galaxy. We infer a star formation history peaked at $\gtrsim 10$ Gyr ago, with subsequent exponential decline leading to a low current star formation rate of 0.01 M${}_{\odot }$ yr${}^{-1}$, which we convert into a binary merger timescale probability distribution. We find a median merger timescale of $11.2_{-1.4}^{+0.7}$ Gyr, with a 90% confidence range of $6.8-13.6$ Gyr. This in turn indicates an initial binary separation of $\approx 4.5$ R${}_{\odot }$, comparable to the inferred values for Galactic BNS systems. We also use new and archival $Hubble$ $Space$ $Telescope$ images to measure a projected offset of the optical counterpart of $2.1$ kpc (0.64$r_e$) from the center of NGC 4993 and to place a limit of $M_r\gtrsim -7.2$ mag on any pre-existing emission, which rules out the brighter half of the globular cluster luminosity function. Finally, the age and offset of the system indicates it experienced a modest natal kick with an upper limit of $\sim 200$ km s${}^{-1}$. Future GW$-$EM observations of BNS mergers will enable measurement of their population delay time distribution, which will directly inform their viability as the dominant source of $r$-process enrichment in the Universe.

9 Pages, 3 Figures, 2 Tables, ApJL, In Press. Keywords: GW170817, LVC

References in corpus (15)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• An Ordinary Short Gamma-Ray Burst with Extraordinary Implications: Fermi-GBM Detection of GRB 170817A
• Swope Supernova Survey 2017a (SSS17a), the Optical Counterpart to a Gravitational Wave Source
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. II. UV, Optical, and Near-IR Light Curves and Comparison to Kilonova Models
• INTEGRAL Detection of the First Prompt Gamma-Ray Signal Coincident with the Gravitational Wave Event GW170817
• Long gamma-ray bursts and core-collapse supernovae have different environments
• Formation of Double Neutron Star Systems
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Dark Energy Camera Discovery of the Optical Counterpart
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. IV. Detection of Near-infrared Signatures of r-process Nucleosynthesis with Gemini-South
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. III. Optical and UV Spectra of a Blue Kilonova From Fast Polar Ejecta
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. V. Rising X-ray Emission from an Off-Axis Jet
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VI. Radio Constraints on a Relativistic Jet and Predictions for Late-Time Emission from the Kilonova Ejecta
• Formation of Double Compact Objects
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VIII. A Comparison to Cosmological Short-duration Gamma-ray Bursts
• Constraints on Natal Kicks in Galactic Double Neutron Star Systems

Cited by in corpus (63)

• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. II. UV, Optical, and Near-IR Light Curves and Comparison to Kilonova Models
• Stellar Population Inference with Prospector
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Dark Energy Camera Discovery of the Optical Counterpart
• The Combined Ultraviolet, Optical, and Near-Infrared Light Curves of the Kilonova Associated with the Binary Neutron Star Merger GW170817: Unified Data Set, Analytic Models, and Physical Implications
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. III. Optical and UV Spectra of a Blue Kilonova From Fast Polar Ejecta
• Kilonovae
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. V. Rising X-ray Emission from an Off-Axis Jet
• A Kilonova Following a Long-Duration Gamma-Ray Burst at 350 Mpc
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VI. Radio Constraints on a Relativistic Jet and Predictions for Late-Time Emission from the Kilonova Ejecta
• Short GRB Host Galaxies I: Photometric and Spectroscopic Catalogs, Host Associations, and Galactocentric Offsets
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VIII. A Comparison to Cosmological Short-duration Gamma-ray Bursts
• Improved constraints on H0 from a combined analysis of gravitational-wave and electromagnetic emission from GW170817
• Searching for Electromagnetic Counterparts to Gravitational-wave Merger Events with the Prototype Gravitational-wave Optical Transient Observer (GOTO-4)
• Host galaxies of merging compact objects: mass, star formation rate, metallicity and colours
• Tight multi-messenger constraints on the neutron star equation of state from GW170817 and a forward model for kilonova light curve synthesis
• Short GRB Host Galaxies. II. A Legacy Sample of Redshifts, Stellar Population Properties, and Implications for their Neutron Star Merger Origins
• A standard siren measurement of the Hubble constant using gravitational wave events from the first three LIGO/Virgo observing runs and the DESI Legacy Survey
• Evidence for X-ray Emission in Excess to the Jet Afterglow Decay 3.5 yrs After the Binary Neutron Star Merger GW 170817: A New Emission Component
• Formation channels of single and binary stellar-mass black holes
• $R$-process enhancements of Gaia-Enceladus in GALAH DR3
• Evidence for Dynamically Driven Formation of the GW170817 Neutron Star Binary in NGC 4993
• Evidence from Disrupted Halo Dwarfs that $r$-process Enrichment via Neutron Star Mergers is Delayed by $\gtrsim 500$ Myrs
• Constraining the Hubble constant to a precision of about 1% using multi-band dark standard siren detections
• A brief overview of black hole-neutron star mergers
• Updated Parameter Estimates for GW190425 Using Astrophysical Arguments and Implications for the Electromagnetic Counterpart
• Formation and Evolution of Binary Neutron Stars: Mergers and Their Host Galaxies
• Evidence for $\gtrsim 4$ Gyr timescales of neutron star mergers from Galactic archaeology
• Optimising gravitational waves follow-up using galaxies stellar mass
• Observational Inference on the Delay Time Distribution of Short Gamma-ray Bursts
• Constraints on the Physical Properties of GW190814 through Simulations based on DECam Follow-up Observations by the Dark Energy Survey
• Double Neutron Star Formation: Merger Times, Systemic Velocities, and Travel Distances
• A multi-wavelength analysis of a collection of short-duration GRBs observed between 2012-2015
• Timing the r-Process Enrichment of the Ultra-Faint Dwarf Galaxy Reticulum II
• Deep Hubble Space Telescope Observations of GW170817: Complete Light Curves and the Properties of the Galaxy Merger of NGC 4993
• The binary-host connection: astrophysics of gravitational wave binaries from their host galaxy properties
• The distant, galaxy cluster environment of the short GRB 161104A at $z\sim 0.8$ and a comparison to the short GRB host population
• Measuring the delay time distribution of binary neutron stars. I. Through Scaling Relations of the Host Galaxies of Gravitational Wave Events
• A Comparative Study of Long and Short GRBs. II. A Multi-wavelength Method to distinguish Type II (massive star) and Type I (compact star) GRBs
• Evidence for r-process delay in very metal-poor stars
• Measuring the Hubble constant with kilonovae using the Expanding Photosphere Method
• Multiple Peaks and a Long Precursor in the Type IIn Supernova 2021qqp: An Energetic Explosion in a Complex Circumstellar Environment
• Characterizing Astrophysical Binary Neutron Stars with Gravitational Waves
• Constraining Delay Time Distribution of Binary Neutron Star Mergers from Host Galaxy Properties
• End-to-end study of the home and genealogy of the first binary neutron star merger
• Radio Afterglows from Compact Binary Coalescences: Prospects for Next-Generation Telescopes
• Target of Opportunity Observations Detectability of Kilonovae with WFST
• Observational constraints on the origin of the elements. VI. Origin and evolution of neutron-capture elements as probed by the Gaia-ESO survey
• Peeking beneath the precision floor -- II. Probing the chemo-dynamical histories of the potential globular cluster siblings, NGC 288 and NGC 362
• Detection of VHE gamma-ray transients with monitoring facilities
• Measuring Star Formation Histories, Distances, and Metallicities with Pixel Color-Magnitude Diagrams II: Applications to Nearby Elliptical Galaxies
• Where binary neutron stars merge: predictions from IllustrisTNG
• Search for radio remnants of nearby off-axis Gamma-Ray Bursts in a sample of Swift/BAT events
• Self-Supervised Clustering on Image-Subtracted Data with Deep-Embedded Self-Organizing Map
• Simulating Kilonovae in the ΛCDM Universe
• Where has all the $r$-process gone? Timescales for GRB-Kilonovae to Enrich their Host Galaxies
• Simulation of the orbit and spin period evolution of the double pulsars PSR J0737-3039 from their birth to coalescence induced by the gravitational wave radiation
• Gamma-Ray Burst detection prospects for next generation ground-based VHE facilities
• Binary neutron star merger offsets from their host galaxies II. Short-duration gamma-ray bursts
• Binary Neutron Star (BNS) merger: What we learned from relativistic ejecta of GW/GRB~170817A
• The Spatially Resolved Properties of the GW170817 Host Galaxy
• Radio astronomy and Space science in Azores: enhancing the Atlantic VLBI infrastructure cluster
• Resolving the fastest ejecta from binary Neutron Star mergers: implications for electromagnetic counterparts
• A DESGW Search for the Electromagnetic Counterpart to the LIGO/Virgo Gravitational Wave Binary Neutron Star Merger Candidate S190510g