The Discovery of the Electromagnetic Counterpart of GW170817: Kilonova AT 2017gfo/DLT17ck

By S. Valenti, D. Sand, Shengqi Yang, E. Cappellaro, L. Tartaglia, A. Corsi, S. Jha, D. Reichart, J. Haislip, V. Kouprianov. 2017

356 citations recorded by the source corpus.

During the second observing run of the Laser Interferometer Gravitational-wave Observatory (LIGO) and Virgo Interferometer, a gravitational-wave signal consistent with a binary neutron star coalescence was detected on 2017 August 17th (GW170817), quickly followed by a coincident short gamma-ray burst trigger detected by the Fermi satellite. The Distance Less Than 40 (DLT40) Mpc supernova search performed pointed follow-up observations of a sample of galaxies regularly monitored by the survey that fell within the combined LIGO+Virgo localization region and the larger Fermi gamma-ray burst error box. Here we report the discovery of a new optical transient (DLT17ck, also known as SSS17a; it has also been registered as AT 2017gfo) spatially and temporally coincident with GW170817. The photometric and spectroscopic evolution of DLT17ck is unique, with an absolute peak magnitude of Mr = −15.8 ± 0.1 and an r-band decline rate of 1.1 mag day−1. This fast evolution is generically consistent with kilonova models, which have been predicted as the optical counterpart to binary neutron star coalescences. Analysis of archival DLT40 data does not show any sign of transient activity at the location of DLT17ck down to r ∼ 19 mag in the time period between 8 months and 21 days prior to GW170817. This discovery represents the beginning of a new era for multi-messenger astronomy, opening a new path by which to study and understand binary neutron star coalescences, short gamma-ray bursts, and their optical counterparts.

Subfields: Astronomy and Astrophysics, Geophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/ce3a646f9ef4ac7163a8b9efe26387f843f92977

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Citations in the corpus

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 (2017, background): “…2017b), termed GRB 170817A. Subsequently, an 14 Hubble Fellow. optical counterpart15 was also discovered by several teams, including by our group with the Dark Energy Camera (DECam; Allam et al. 2017; Coulter et al. 2017a, 2017b; Soares-Santos et al. 2017; Valenti et al. 2017; Yang et al. 2017).”
The Binary Neutron Star Event LIGO/Virgo GW170817 160 Days after Merger: Synchrotron Emission across the Electromagnetic Spectrum (2018, background): “…Drout et al. 2017; Kasliwal et al. 2017; Nicholl et al. 2017; Pian et al. 2017; Smartt et al. 2017; Soares-Santos et al. 2017; Tanvir et al. 2017; Valenti et al. 2017; Villar et al. 2017) and nonthermal synchrotron emission dominating in the X-rays and 1 Center for Interdisciplinary Exploration…”
The evolution of the X-ray afterglow emission of GW 170817 / GRB 170817A in XMM-Newton observations (2018, background): “…to a rapid (∆t < 11 h) identification of a relatively bright optical electromagnetic counterpart (EM), named AT2017gfo, in the galaxy NGC 4993 (Arcavi et al. 2017; Coulter et al. 2017; Lipunov et al. 2017; Melandri et al. 2017; Tanvir et al. 2017; Soares-Santos et al. 2017; Valenti et al. 2017).”
Follow Up of GW170817 and Its Electromagnetic Counterpart by Australian-Led Observing Programmes (2017, background): “Details about the other independent detections can be found in Allam et al. (2017) for the Dark Energy Camera, Valenti et al. (2017) and Yang et al. (2017) for the Distance Less Than 40 Mpc survey (DLT40), Arcavi et al. (2017a) and Arcavi et al. (2017b) for the Las Cumbres Observatory, Tanvir et…”
Constraints on the neutron star equation of state from AT2017gfo using radiative transfer simulations (2018, background): “…et al. 2017; Evans et al. 2017; Kasliwal et al. 2017; Tanvir et al. 2017; Pian et al. 2017a; Troja et al. 2017; Smartt et al. 2017; Utsumi et al. 2017; Valenti et al. 2017) from phases +0.467 to +25.19 d after GW170817 and at each epoch created the broadest spectral energy distribution possible.”
The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. II. UV, Optical, and Near-infrared Light Curves and Comparison to Kilonova Models (2017, background): “The source has also been independently named DLT17ck (Valenti et al. 2017; Yang et al. 2017) and AT2017gfo.”
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 (2017, methodology): “…et al. (2017a,b), was independently discovered by our group, using the Dark Energy Camera on the 4-m Blanco Telescope (Allam et al. 2017; Soares-Santos et al. 2017), and by several other groups (Yang et al. 2017; Valenti et al. 2017; Arcavi et al. 2017a,b; Tanvir et al. 2017; Lipunov et al. 2017).”
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 (2017, methodology): “This optical transient source was variously given the name of SSS17a (Coulter et al. 2017a, 2017b) and DLT17ck (Valenti et al. 2017; Yang et al. 2017), as well as an International Astronomical Union name of AT2017gfo.”
The Emergence of a Lanthanide-rich Kilonova Following the Merger of Two Neutron Stars (2017, background): “Contemporaneous observations made independently with several optical telescopes also revealed a new source at this location (Allam et al. 2017; Coulter et al. 2017; Valenti et al. 2017), which was designated AT2017gfo (also referred to as SSS17a or DLT17ck).”
INTEGRAL Detection of the First Prompt Gamma-Ray Signal Coincident with the Gravitational-wave Event GW170817 (2017, background): “A massive follow-up campaign of the LIGO–Virgo highprobability region by optical robotic telescopes started immediately after the event and on 2017 August 18 between 1:05 and 1:45 UT; three groups reported independent detections of a transient optical source at about 10 arcsec from the center of the”
Three-dimensional GRMHD Simulations of Neutrino-cooled Accretion Disks from Neutron Star Mergers (2017, neutral): “Eleven hours after the merger, an optical counterpart was discovered (Coulter et al. 2017; Soares-Santos et al. 2017; Valenti et al. 2017; Arcavi et al. 2017; Lipunov et al. 2017; Evans et al. 2017) with a luminosity, thermal spectrum, and rapid temporal decay consistent with “kilonova” (KN)…”