The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Discovery of the Optical Counterpart Using the Dark Energy Camera

M. Soares-Santos, D. E. Holz, J. Annis, R. Chornock, K. Herner, E. Berger, D. Brout, H. Y. Chen, R. Kessler, M. Sako, S. Allam, D. L. Tucker, R. E. Butler, A. Palmese, Z. Doctor, H. T. Diehl, J. Frieman, B. Yanny, H. Lin, D. Scolnic & 125 others P. Cowperthwaite, E. Neilsen, J. Marriner, N. Kuropatkin, W. G. Hartley, F. Paz-Chinchón, K. D. Alexander, E. Balbinot, P. Blanchard, Duncan Brown, J. L. Carlin, C. Conselice, E. R. Cook, A. Drlica-Wagner, M. R. Drout, F. Durret, T. Eftekhari, B. Farr, D. A. Finley, R. J. Foley, W. Fong, C. L. Fryer, J. García-Bellido, M. S.S. Gill, R. A. Gruendl, C. Hanna, D. Kasen, T. S. Li, P. A.A. Lopes, A. C.C. Lourenço, R. Margutti, J. L. Marshall, T. Matheson, G. E. Medina, B. D. Metzger, R. R. Muñoz, J. Muir, M. Nicholl, E. Quataert, A. Rest, M. Sauseda, D. J. Schlegel, L. F. Secco, F. Sobreira, A. Stebbins, V. A. Villar, A. R. Walker, W. Wester, P. K.G. Williams, A. Zenteno, Y. Zhang, T. M.C. Abbott, F. B. Abdalla, M. Banerji, K. Bechtol, A. Benoit-Lévy, E. Bertin, D. Brooks, E. Buckley-Geer, D. L. Burke, A. Carnero Rosell, M. Carrasco Kind, J. Carretero, F. J. Castander, M. Crocce, C. E. Cunha, C. B. D'Andrea, L. N.Da Costa, C. Davis, S. Desai, J. P. Dietrich, P. Doel, T. F. Eifler, E. Fernandez, B. Flaugher, P. Fosalba, E. Gaztanaga, D. W. Gerdes, T. Giannantonio, D. A. Goldstein, D. Gruen, J. Gschwend, G. Gutierrez, K. Honscheid, B. Jain, D. J. James, T. Jeltema, M. W.G. Johnson, M. D. Johnson, S. Kent, E. Krause, R. Kron, K. Kuehn, S. Kuhlmann, O. Lahav, M. Lima, M. A.G. Maia, M. March, R. G. McMahon, F. Menanteau, R. Miquel, J. J. Mohr, R. C. Nichol, B. Nord, R. L.C. Ogando, D. Petravick, A. A. Plazas, A. K. Romer, A. Roodman, E. S. Rykoff, E. Sanchez, V. Scarpine, M. Schubnell, I. Sevilla-Noarbe, M. Smith, R. C. Smith, E. Suchyta, M. E.C. Swanson, G. Tarle, D. Thomas, R. C. Thomas, M. A. Troxel, V. Vikram, R. H. Wechsler, J. Weller

Research output: Contribution to journalArticle

137 Citations (Scopus)

Abstract

We present the Dark Energy Camera (DECam) discovery of the optical counterpart of the first binary neutron star merger detected through gravitational-wave emission, GW170817. Our observations commenced 10.5 hr post-merger, as soon as the localization region became accessible from Chile. We imaged 70 deg2 in the i and z bands, covering 93% of the initial integrated localization probability, to a depth necessary to identify likely optical counterparts (e.g., a kilonova). At 11.4 hr post-merger we detected a bright optical transient located from the nucleus of NGC 4993 at redshift z = 0.0098, consistent (for km s-1 Mpc-1) with the distance of 40 ±8 Mpc reported by the LIGO Scientific Collaboration and the Virgo Collaboration (LVC). At detection the transient had magnitudes of and , and thus an absolute magnitude of , in the luminosity range expected for a kilonova. We identified 1500 potential transient candidates. Applying simple selection criteria aimed at rejecting background events such as supernovae, we find the transient associated with NGC 4993 as the only remaining plausible counterpart, and reject chance coincidence at the 99.5% confidence level. We therefore conclude that the optical counterpart we have identified near NGC 4993 is associated with GW170817. This discovery ushers in the era of multi-messenger astronomy with gravitational waves and demonstrates the power of DECam to identify the optical counterparts of gravitational-wave sources.

Original languageEnglish (US)
Article numberL16
JournalAstrophysical Journal Letters
Volume848
Issue number2
DOIs
StatePublished - Oct 20 2017

Fingerprint

LIGO (observatory)
binary stars
dark energy
gravitational waves
merger
neutron stars
cameras
electromagnetism
energy
Chile
astronomy
supernovae
confidence
coverings
luminosity
nuclei

Keywords

  • binaries: close
  • catalogs
  • gravitational waves
  • stars: neutron
  • surveys

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Discovery of the Optical Counterpart Using the Dark Energy Camera. / Soares-Santos, M.; Holz, D. E.; Annis, J.; Chornock, R.; Herner, K.; Berger, E.; Brout, D.; Chen, H. Y.; Kessler, R.; Sako, M.; Allam, S.; Tucker, D. L.; Butler, R. E.; Palmese, A.; Doctor, Z.; Diehl, H. T.; Frieman, J.; Yanny, B.; Lin, H.; Scolnic, D.; Cowperthwaite, P.; Neilsen, E.; Marriner, J.; Kuropatkin, N.; Hartley, W. G.; Paz-Chinchón, F.; Alexander, K. D.; Balbinot, E.; Blanchard, P.; Brown, Duncan; Carlin, J. L.; Conselice, C.; Cook, E. R.; Drlica-Wagner, A.; Drout, M. R.; Durret, F.; Eftekhari, T.; Farr, B.; Finley, D. A.; Foley, R. J.; Fong, W.; Fryer, C. L.; García-Bellido, J.; Gill, M. S.S.; Gruendl, R. A.; Hanna, C.; Kasen, D.; Li, T. S.; Lopes, P. A.A.; Lourenço, A. C.C.; Margutti, R.; Marshall, J. L.; Matheson, T.; Medina, G. E.; Metzger, B. D.; Muñoz, R. R.; Muir, J.; Nicholl, M.; Quataert, E.; Rest, A.; Sauseda, M.; Schlegel, D. J.; Secco, L. F.; Sobreira, F.; Stebbins, A.; Villar, V. A.; Walker, A. R.; Wester, W.; Williams, P. K.G.; Zenteno, A.; Zhang, Y.; Abbott, T. M.C.; Abdalla, F. B.; Banerji, M.; Bechtol, K.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Rosell, A. Carnero; Kind, M. Carrasco; Carretero, J.; Castander, F. J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; Costa, L. N.Da; Davis, C.; Desai, S.; Dietrich, J. P.; Doel, P.; Eifler, T. F.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Gaztanaga, E.; Gerdes, D. W.; Giannantonio, T.; Goldstein, D. A.; Gruen, D.; Gschwend, J.; Gutierrez, G.; Honscheid, K.; Jain, B.; James, D. J.; Jeltema, T.; Johnson, M. W.G.; Johnson, M. D.; Kent, S.; Krause, E.; Kron, R.; Kuehn, K.; Kuhlmann, S.; Lahav, O.; Lima, M.; Maia, M. A.G.; March, M.; McMahon, R. G.; Menanteau, F.; Miquel, R.; Mohr, J. J.; Nichol, R. C.; Nord, B.; Ogando, R. L.C.; Petravick, D.; Plazas, A. A.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Suchyta, E.; Swanson, M. E.C.; Tarle, G.; Thomas, D.; Thomas, R. C.; Troxel, M. A.; Vikram, V.; Wechsler, R. H.; Weller, J.

In: Astrophysical Journal Letters, Vol. 848, No. 2, L16, 20.10.2017.

Research output: Contribution to journalArticle

Soares-Santos, M, Holz, DE, Annis, J, Chornock, R, Herner, K, Berger, E, Brout, D, Chen, HY, Kessler, R, Sako, M, Allam, S, Tucker, DL, Butler, RE, Palmese, A, Doctor, Z, Diehl, HT, Frieman, J, Yanny, B, Lin, H, Scolnic, D, Cowperthwaite, P, Neilsen, E, Marriner, J, Kuropatkin, N, Hartley, WG, Paz-Chinchón, F, Alexander, KD, Balbinot, E, Blanchard, P, Brown, D, Carlin, JL, Conselice, C, Cook, ER, Drlica-Wagner, A, Drout, MR, Durret, F, Eftekhari, T, Farr, B, Finley, DA, Foley, RJ, Fong, W, Fryer, CL, García-Bellido, J, Gill, MSS, Gruendl, RA, Hanna, C, Kasen, D, Li, TS, Lopes, PAA, Lourenço, ACC, Margutti, R, Marshall, JL, Matheson, T, Medina, GE, Metzger, BD, Muñoz, RR, Muir, J, Nicholl, M, Quataert, E, Rest, A, Sauseda, M, Schlegel, DJ, Secco, LF, Sobreira, F, Stebbins, A, Villar, VA, Walker, AR, Wester, W, Williams, PKG, Zenteno, A, Zhang, Y, Abbott, TMC, Abdalla, FB, Banerji, M, Bechtol, K, Benoit-Lévy, A, Bertin, E, Brooks, D, Buckley-Geer, E, Burke, DL, Rosell, AC, Kind, MC, Carretero, J, Castander, FJ, Crocce, M, Cunha, CE, D'Andrea, CB, Costa, LND, Davis, C, Desai, S, Dietrich, JP, Doel, P, Eifler, TF, Fernandez, E, Flaugher, B, Fosalba, P, Gaztanaga, E, Gerdes, DW, Giannantonio, T, Goldstein, DA, Gruen, D, Gschwend, J, Gutierrez, G, Honscheid, K, Jain, B, James, DJ, Jeltema, T, Johnson, MWG, Johnson, MD, Kent, S, Krause, E, Kron, R, Kuehn, K, Kuhlmann, S, Lahav, O, Lima, M, Maia, MAG, March, M, McMahon, RG, Menanteau, F, Miquel, R, Mohr, JJ, Nichol, RC, Nord, B, Ogando, RLC, Petravick, D, Plazas, AA, Romer, AK, Roodman, A, Rykoff, ES, Sanchez, E, Scarpine, V, Schubnell, M, Sevilla-Noarbe, I, Smith, M, Smith, RC, Suchyta, E, Swanson, MEC, Tarle, G, Thomas, D, Thomas, RC, Troxel, MA, Vikram, V, Wechsler, RH & Weller, J 2017, 'The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Discovery of the Optical Counterpart Using the Dark Energy Camera', Astrophysical Journal Letters, vol. 848, no. 2, L16. https://doi.org/10.3847/2041-8213/aa9059
Soares-Santos, M. ; Holz, D. E. ; Annis, J. ; Chornock, R. ; Herner, K. ; Berger, E. ; Brout, D. ; Chen, H. Y. ; Kessler, R. ; Sako, M. ; Allam, S. ; Tucker, D. L. ; Butler, R. E. ; Palmese, A. ; Doctor, Z. ; Diehl, H. T. ; Frieman, J. ; Yanny, B. ; Lin, H. ; Scolnic, D. ; Cowperthwaite, P. ; Neilsen, E. ; Marriner, J. ; Kuropatkin, N. ; Hartley, W. G. ; Paz-Chinchón, F. ; Alexander, K. D. ; Balbinot, E. ; Blanchard, P. ; Brown, Duncan ; Carlin, J. L. ; Conselice, C. ; Cook, E. R. ; Drlica-Wagner, A. ; Drout, M. R. ; Durret, F. ; Eftekhari, T. ; Farr, B. ; Finley, D. A. ; Foley, R. J. ; Fong, W. ; Fryer, C. L. ; García-Bellido, J. ; Gill, M. S.S. ; Gruendl, R. A. ; Hanna, C. ; Kasen, D. ; Li, T. S. ; Lopes, P. A.A. ; Lourenço, A. C.C. ; Margutti, R. ; Marshall, J. L. ; Matheson, T. ; Medina, G. E. ; Metzger, B. D. ; Muñoz, R. R. ; Muir, J. ; Nicholl, M. ; Quataert, E. ; Rest, A. ; Sauseda, M. ; Schlegel, D. J. ; Secco, L. F. ; Sobreira, F. ; Stebbins, A. ; Villar, V. A. ; Walker, A. R. ; Wester, W. ; Williams, P. K.G. ; Zenteno, A. ; Zhang, Y. ; Abbott, T. M.C. ; Abdalla, F. B. ; Banerji, M. ; Bechtol, K. ; Benoit-Lévy, A. ; Bertin, E. ; Brooks, D. ; Buckley-Geer, E. ; Burke, D. L. ; Rosell, A. Carnero ; Kind, M. Carrasco ; Carretero, J. ; Castander, F. J. ; Crocce, M. ; Cunha, C. E. ; D'Andrea, C. B. ; Costa, L. N.Da ; Davis, C. ; Desai, S. ; Dietrich, J. P. ; Doel, P. ; Eifler, T. F. ; Fernandez, E. ; Flaugher, B. ; Fosalba, P. ; Gaztanaga, E. ; Gerdes, D. W. ; Giannantonio, T. ; Goldstein, D. A. ; Gruen, D. ; Gschwend, J. ; Gutierrez, G. ; Honscheid, K. ; Jain, B. ; James, D. J. ; Jeltema, T. ; Johnson, M. W.G. ; Johnson, M. D. ; Kent, S. ; Krause, E. ; Kron, R. ; Kuehn, K. ; Kuhlmann, S. ; Lahav, O. ; Lima, M. ; Maia, M. A.G. ; March, M. ; McMahon, R. G. ; Menanteau, F. ; Miquel, R. ; Mohr, J. J. ; Nichol, R. C. ; Nord, B. ; Ogando, R. L.C. ; Petravick, D. ; Plazas, A. A. ; Romer, A. K. ; Roodman, A. ; Rykoff, E. S. ; Sanchez, E. ; Scarpine, V. ; Schubnell, M. ; Sevilla-Noarbe, I. ; Smith, M. ; Smith, R. C. ; Suchyta, E. ; Swanson, M. E.C. ; Tarle, G. ; Thomas, D. ; Thomas, R. C. ; Troxel, M. A. ; Vikram, V. ; Wechsler, R. H. ; Weller, J. / The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Discovery of the Optical Counterpart Using the Dark Energy Camera. In: Astrophysical Journal Letters. 2017 ; Vol. 848, No. 2.
@article{0d6a1319012d4989bc7afe99bca4e3ed,
title = "The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Discovery of the Optical Counterpart Using the Dark Energy Camera",
abstract = "We present the Dark Energy Camera (DECam) discovery of the optical counterpart of the first binary neutron star merger detected through gravitational-wave emission, GW170817. Our observations commenced 10.5 hr post-merger, as soon as the localization region became accessible from Chile. We imaged 70 deg2 in the i and z bands, covering 93{\%} of the initial integrated localization probability, to a depth necessary to identify likely optical counterparts (e.g., a kilonova). At 11.4 hr post-merger we detected a bright optical transient located from the nucleus of NGC 4993 at redshift z = 0.0098, consistent (for km s-1 Mpc-1) with the distance of 40 ±8 Mpc reported by the LIGO Scientific Collaboration and the Virgo Collaboration (LVC). At detection the transient had magnitudes of and , and thus an absolute magnitude of , in the luminosity range expected for a kilonova. We identified 1500 potential transient candidates. Applying simple selection criteria aimed at rejecting background events such as supernovae, we find the transient associated with NGC 4993 as the only remaining plausible counterpart, and reject chance coincidence at the 99.5{\%} confidence level. We therefore conclude that the optical counterpart we have identified near NGC 4993 is associated with GW170817. This discovery ushers in the era of multi-messenger astronomy with gravitational waves and demonstrates the power of DECam to identify the optical counterparts of gravitational-wave sources.",
keywords = "binaries: close, catalogs, gravitational waves, stars: neutron, surveys",
author = "M. Soares-Santos and Holz, {D. E.} and J. Annis and R. Chornock and K. Herner and E. Berger and D. Brout and Chen, {H. Y.} and R. Kessler and M. Sako and S. Allam and Tucker, {D. L.} and Butler, {R. E.} and A. Palmese and Z. Doctor and Diehl, {H. T.} and J. Frieman and B. Yanny and H. Lin and D. Scolnic and P. Cowperthwaite and E. Neilsen and J. Marriner and N. Kuropatkin and Hartley, {W. G.} and F. Paz-Chinch{\'o}n and Alexander, {K. D.} and E. Balbinot and P. Blanchard and Duncan Brown and Carlin, {J. L.} and C. Conselice and Cook, {E. R.} and A. Drlica-Wagner and Drout, {M. R.} and F. Durret and T. Eftekhari and B. Farr and Finley, {D. A.} and Foley, {R. J.} and W. Fong and Fryer, {C. L.} and J. Garc{\'i}a-Bellido and Gill, {M. S.S.} and Gruendl, {R. A.} and C. Hanna and D. Kasen and Li, {T. S.} and Lopes, {P. A.A.} and Louren{\cc}o, {A. C.C.} and R. Margutti and Marshall, {J. L.} and T. Matheson and Medina, {G. E.} and Metzger, {B. D.} and Mu{\~n}oz, {R. R.} and J. Muir and M. Nicholl and E. Quataert and A. Rest and M. Sauseda and Schlegel, {D. J.} and Secco, {L. F.} and F. Sobreira and A. Stebbins and Villar, {V. A.} and Walker, {A. R.} and W. Wester and Williams, {P. K.G.} and A. Zenteno and Y. Zhang and Abbott, {T. M.C.} and Abdalla, {F. B.} and M. Banerji and K. Bechtol and A. Benoit-L{\'e}vy and E. Bertin and D. Brooks and E. Buckley-Geer and Burke, {D. L.} and Rosell, {A. Carnero} and Kind, {M. Carrasco} and J. Carretero and Castander, {F. J.} and M. Crocce and Cunha, {C. E.} and D'Andrea, {C. B.} and Costa, {L. N.Da} and C. Davis and S. Desai and Dietrich, {J. P.} and P. Doel and Eifler, {T. F.} and E. Fernandez and B. Flaugher and P. Fosalba and E. Gaztanaga and Gerdes, {D. W.} and T. Giannantonio and Goldstein, {D. A.} and D. Gruen and J. Gschwend and G. Gutierrez and K. Honscheid and B. Jain and James, {D. J.} and T. Jeltema and Johnson, {M. W.G.} and Johnson, {M. D.} and S. Kent and E. Krause and R. Kron and K. Kuehn and S. Kuhlmann and O. Lahav and M. Lima and Maia, {M. A.G.} and M. March and McMahon, {R. G.} and F. Menanteau and R. Miquel and Mohr, {J. J.} and Nichol, {R. C.} and B. Nord and Ogando, {R. L.C.} and D. Petravick and Plazas, {A. A.} and Romer, {A. K.} and A. Roodman and Rykoff, {E. S.} and E. Sanchez and V. Scarpine and M. Schubnell and I. Sevilla-Noarbe and M. Smith and Smith, {R. C.} and E. Suchyta and Swanson, {M. E.C.} and G. Tarle and D. Thomas and Thomas, {R. C.} and Troxel, {M. A.} and V. Vikram and Wechsler, {R. H.} and J. Weller",
year = "2017",
month = "10",
day = "20",
doi = "10.3847/2041-8213/aa9059",
language = "English (US)",
volume = "848",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "2",

}

TY - JOUR

T1 - The Electromagnetic Counterpart of the Binary Neutron Star Merger LIGO/Virgo GW170817. I. Discovery of the Optical Counterpart Using the Dark Energy Camera

AU - Soares-Santos, M.

AU - Holz, D. E.

AU - Annis, J.

AU - Chornock, R.

AU - Herner, K.

AU - Berger, E.

AU - Brout, D.

AU - Chen, H. Y.

AU - Kessler, R.

AU - Sako, M.

AU - Allam, S.

AU - Tucker, D. L.

AU - Butler, R. E.

AU - Palmese, A.

AU - Doctor, Z.

AU - Diehl, H. T.

AU - Frieman, J.

AU - Yanny, B.

AU - Lin, H.

AU - Scolnic, D.

AU - Cowperthwaite, P.

AU - Neilsen, E.

AU - Marriner, J.

AU - Kuropatkin, N.

AU - Hartley, W. G.

AU - Paz-Chinchón, F.

AU - Alexander, K. D.

AU - Balbinot, E.

AU - Blanchard, P.

AU - Brown, Duncan

AU - Carlin, J. L.

AU - Conselice, C.

AU - Cook, E. R.

AU - Drlica-Wagner, A.

AU - Drout, M. R.

AU - Durret, F.

AU - Eftekhari, T.

AU - Farr, B.

AU - Finley, D. A.

AU - Foley, R. J.

AU - Fong, W.

AU - Fryer, C. L.

AU - García-Bellido, J.

AU - Gill, M. S.S.

AU - Gruendl, R. A.

AU - Hanna, C.

AU - Kasen, D.

AU - Li, T. S.

AU - Lopes, P. A.A.

AU - Lourenço, A. C.C.

AU - Margutti, R.

AU - Marshall, J. L.

AU - Matheson, T.

AU - Medina, G. E.

AU - Metzger, B. D.

AU - Muñoz, R. R.

AU - Muir, J.

AU - Nicholl, M.

AU - Quataert, E.

AU - Rest, A.

AU - Sauseda, M.

AU - Schlegel, D. J.

AU - Secco, L. F.

AU - Sobreira, F.

AU - Stebbins, A.

AU - Villar, V. A.

AU - Walker, A. R.

AU - Wester, W.

AU - Williams, P. K.G.

AU - Zenteno, A.

AU - Zhang, Y.

AU - Abbott, T. M.C.

AU - Abdalla, F. B.

AU - Banerji, M.

AU - Bechtol, K.

AU - Benoit-Lévy, A.

AU - Bertin, E.

AU - Brooks, D.

AU - Buckley-Geer, E.

AU - Burke, D. L.

AU - Rosell, A. Carnero

AU - Kind, M. Carrasco

AU - Carretero, J.

AU - Castander, F. J.

AU - Crocce, M.

AU - Cunha, C. E.

AU - D'Andrea, C. B.

AU - Costa, L. N.Da

AU - Davis, C.

AU - Desai, S.

AU - Dietrich, J. P.

AU - Doel, P.

AU - Eifler, T. F.

AU - Fernandez, E.

AU - Flaugher, B.

AU - Fosalba, P.

AU - Gaztanaga, E.

AU - Gerdes, D. W.

AU - Giannantonio, T.

AU - Goldstein, D. A.

AU - Gruen, D.

AU - Gschwend, J.

AU - Gutierrez, G.

AU - Honscheid, K.

AU - Jain, B.

AU - James, D. J.

AU - Jeltema, T.

AU - Johnson, M. W.G.

AU - Johnson, M. D.

AU - Kent, S.

AU - Krause, E.

AU - Kron, R.

AU - Kuehn, K.

AU - Kuhlmann, S.

AU - Lahav, O.

AU - Lima, M.

AU - Maia, M. A.G.

AU - March, M.

AU - McMahon, R. G.

AU - Menanteau, F.

AU - Miquel, R.

AU - Mohr, J. J.

AU - Nichol, R. C.

AU - Nord, B.

AU - Ogando, R. L.C.

AU - Petravick, D.

AU - Plazas, A. A.

AU - Romer, A. K.

AU - Roodman, A.

AU - Rykoff, E. S.

AU - Sanchez, E.

AU - Scarpine, V.

AU - Schubnell, M.

AU - Sevilla-Noarbe, I.

AU - Smith, M.

AU - Smith, R. C.

AU - Suchyta, E.

AU - Swanson, M. E.C.

AU - Tarle, G.

AU - Thomas, D.

AU - Thomas, R. C.

AU - Troxel, M. A.

AU - Vikram, V.

AU - Wechsler, R. H.

AU - Weller, J.

PY - 2017/10/20

Y1 - 2017/10/20

N2 - We present the Dark Energy Camera (DECam) discovery of the optical counterpart of the first binary neutron star merger detected through gravitational-wave emission, GW170817. Our observations commenced 10.5 hr post-merger, as soon as the localization region became accessible from Chile. We imaged 70 deg2 in the i and z bands, covering 93% of the initial integrated localization probability, to a depth necessary to identify likely optical counterparts (e.g., a kilonova). At 11.4 hr post-merger we detected a bright optical transient located from the nucleus of NGC 4993 at redshift z = 0.0098, consistent (for km s-1 Mpc-1) with the distance of 40 ±8 Mpc reported by the LIGO Scientific Collaboration and the Virgo Collaboration (LVC). At detection the transient had magnitudes of and , and thus an absolute magnitude of , in the luminosity range expected for a kilonova. We identified 1500 potential transient candidates. Applying simple selection criteria aimed at rejecting background events such as supernovae, we find the transient associated with NGC 4993 as the only remaining plausible counterpart, and reject chance coincidence at the 99.5% confidence level. We therefore conclude that the optical counterpart we have identified near NGC 4993 is associated with GW170817. This discovery ushers in the era of multi-messenger astronomy with gravitational waves and demonstrates the power of DECam to identify the optical counterparts of gravitational-wave sources.

AB - We present the Dark Energy Camera (DECam) discovery of the optical counterpart of the first binary neutron star merger detected through gravitational-wave emission, GW170817. Our observations commenced 10.5 hr post-merger, as soon as the localization region became accessible from Chile. We imaged 70 deg2 in the i and z bands, covering 93% of the initial integrated localization probability, to a depth necessary to identify likely optical counterparts (e.g., a kilonova). At 11.4 hr post-merger we detected a bright optical transient located from the nucleus of NGC 4993 at redshift z = 0.0098, consistent (for km s-1 Mpc-1) with the distance of 40 ±8 Mpc reported by the LIGO Scientific Collaboration and the Virgo Collaboration (LVC). At detection the transient had magnitudes of and , and thus an absolute magnitude of , in the luminosity range expected for a kilonova. We identified 1500 potential transient candidates. Applying simple selection criteria aimed at rejecting background events such as supernovae, we find the transient associated with NGC 4993 as the only remaining plausible counterpart, and reject chance coincidence at the 99.5% confidence level. We therefore conclude that the optical counterpart we have identified near NGC 4993 is associated with GW170817. This discovery ushers in the era of multi-messenger astronomy with gravitational waves and demonstrates the power of DECam to identify the optical counterparts of gravitational-wave sources.

KW - binaries: close

KW - catalogs

KW - gravitational waves

KW - stars: neutron

KW - surveys

UR - http://www.scopus.com/inward/record.url?scp=85031941432&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85031941432&partnerID=8YFLogxK

U2 - 10.3847/2041-8213/aa9059

DO - 10.3847/2041-8213/aa9059

M3 - Article

VL - 848

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 2

M1 - L16

ER -