SOAR/Goodman Spectroscopic Assessment of Candidate Counterparts of the LIGO-Virgo Event GW190814

Abstract

On 2019 August 14 at 21:10:39 UTC, the LIGO/Virgo Collaboration (LVC) detected a possible neutron star-black hole merger (NSBH), the first ever identified. An extensive search for an optical counterpart of this event, designated GW190814, was undertaken using the Dark Energy Camera (DECam) on the 4m Victor M. Blanco Telescope at the Cerro Tololo Inter-American Observatory. Target of Opportunity interrupts were issued on 8 separate nights to observe 11 candidates using the 4.1m Southern Astrophysical Research (SOAR) telescope's Goodman High Throughput Spectrograph in order to assess whether any of these transients was likely to be an optical counterpart of the possible NSBH merger. Here, we describe the process of observing with SOAR, the analysis of our spectra, our spectroscopic typing methodology, and our resultant conclusion that none of the candidates corresponded to the gravitational wave merger event but were all instead other transients. Finally, we describe the lessons learned from this effort. Application of these lessons will be critical for a successful community spectroscopic follow-up program for LVC observing run 4 (O4) and beyond.

32 pages, 18 figures, accepted for publication by ApJ

References in corpus (43)

• The NumPy array: a structure for efficient numerical computation
• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• Advanced Virgo: a 2nd generation interferometric gravitational wave detector
• Multi-messenger Observations of a Binary Neutron Star Merger
• Advanced LIGO
• GW190814: Gravitational Waves from the Coalescence of a 23 M${}_{\odot }$ Black Hole with a 2.6 M${}_{\odot }$ Compact Object
• Origin of the heavy elements in binary neutron-star mergers from a gravitational wave event
• Spectroscopic identification of r-process nucleosynthesis in a double neutron star merger
• INTEGRAL Detection of the First Prompt Gamma-Ray Signal Coincident with the Gravitational Wave Event GW170817
• A kilonova as the electromagnetic counterpart to a gravitational-wave source
• The X-ray counterpart to the gravitational wave event GW 170817
• Light Curves of the Neutron Star Merger GW170817/SSS17a: Implications for R-Process Nucleosynthesis
• Optical emission from a kilonova following a gravitational-wave-detected neutron-star merger
• 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
• A Radio Counterpart to a Neutron Star Merger
• Determining the Type, Redshift, and Age of a Supernova Spectrum
• 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
• Identification of strontium in the merger of two neutron stars
• Modeling GW170817 based on numerical relativity and its implications
• The 1% Concordance Hubble Constant
• 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
• First measurement of the Hubble constant from a dark standard siren using the Dark Energy Survey galaxies and the LIGO/Virgo binary-black-hole merger GW170814
• Dynamics of stellar black holes in young star clusters with different metallicities - II. Black hole-black hole binaries
• Properties of Kilonovae from Dynamical and Post-Merger Ejecta of Neutron Star Mergers
• On the Rate of Neutron Star Binary Mergers from Globular Clusters
• Absolute-Magnitude Distributions of Supernovae
• A statistical standard siren measurement of the Hubble constant from the LIGO/Virgo gravitational wave compact object merger GW190814 and Dark Energy Survey galaxies
• The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/VIRGO GW170817. VIII. A Comparison to Cosmological Short-duration Gamma-ray Bursts
• GROWTH on S190814bv: Deep Synoptic Limits on the Optical/Near-Infrared Counterpart to a Neutron Star-Black Hole Merger
• Observational constraints on the optical and near-infrared emission from the neutron star-black hole binary merger S190814bv
• How Many Kilonovae Can Be Found in Past, Present, and Future Survey Datasets?
• An ASKAP search for a radio counterpart to the first high-significance neutron star-black hole merger LIGO/Virgo S190814bv
• A Deep CFHT Optical Search for a Counterpart to the Possible Neutron Star -- Black Hole Merger GW190814
• Limits on the Electromagnetic Counterpart to S190814bv
• High latitude emission from structured jet of Gamma-Ray Bursts observed off-axis
• A search for optical and near-infrared counterparts of the compact binary merger GW190814
• Constraints on the Physical Properties of GW190814 through Simulations based on DECam Follow-up Observations by the Dark Energy Survey
• Afterglows and Kilonovae Associated with Nearby Low-Luminosity Short-Duration Gamma-Ray Bursts: Application to GW170817/GRB170817A
• The Gravity Collective: A Search for the Electromagnetic Counterpart to the Neutron Star-Black Hole Merger GW190814
• Probing gravity and growth of structure with gravitational waves and galaxies' peculiar velocity
• Optical follow-up of gravitational wave triggers with DECam during the first two LIGO/VIRGO observing runs