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

P. S. Cowperthwaite, E. Berger, V. A. Villar, B. D. Metzger, M. Nicholl, R. Chornock, P. K. Blanchard, W. Fong, R. Margutti, M. Soares-Santos, K. D. Alexander, S. Allam, J. Annis, D. Brout, Duncan Brown, R. E. Butler, H. Y. Chen, H. T. Diehl, Z. Doctor, M. R. Drout & 124 others T. Eftekhari, B. Farr, D. A. Finley, R. J. Foley, J. A. Frieman, C. L. Fryer, J. García-Bellido, M. S.S. Gill, J. Guillochon, K. Herner, D. E. Holz, D. Kasen, R. Kessler, J. Marriner, T. Matheson, E. H. Neilsen, E. Quataert, A. Palmese, A. Rest, M. Sako, D. M. Scolnic, N. Smith, D. L. Tucker, P. K.G. Williams, E. Balbinot, J. L. Carlin, E. R. Cook, F. Durret, T. S. Li, P. A.A. Lopes, A. C.C. Lourenço, J. L. Marshall, G. E. Medina, J. Muir, R. R. Muñoz, M. Sauseda, D. J. Schlegel, L. F. Secco, A. K. Vivas, W. Wester, A. Zenteno, Y. Zhang, T. M.C. Abbott, M. Banerji, K. Bechtol, A. Benoit-Lévy, E. Bertin, E. Buckley-Geer, D. L. Burke, D. Capozzi, A. Carnero Rosell, M. Carrasco Kind, F. J. Castander, M. Crocce, C. E. Cunha, C. B. D'Andrea, L. N.Da Costa, C. Davis, D. L. Depoy, S. Desai, J. P. Dietrich, A. Drlica-Wagner, T. F. Eifler, A. E. Evrard, E. Fernandez, B. Flaugher, P. Fosalba, E. Gaztanaga, D. W. Gerdes, T. Giannantonio, D. A. Goldstein, D. Gruen, R. A. Gruendl, 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, N. Nuropatkin, O. Lahav, M. Lima, H. Lin, M. A.G. Maia, M. March, P. Martini, R. G. McMahon, F. Menanteau, C. J. Miller, R. Miquel, J. J. Mohr, E. Neilsen, R. C. Nichol, R. L.C. Ogando, A. A. Plazas, N. Roe, A. K. Romer, A. Roodman, E. S. Rykoff, E. Sanchez, V. Scarpine, R. Schindler, M. Schubnell, I. Sevilla-Noarbe, M. Smith, R. C. Smith, F. Sobreira, E. Suchyta, M. E.C. Swanson, G. Tarle, D. Thomas, R. C. Thomas, M. A. Troxel, V. Vikram, A. R. Walker, R. H. Wechsler, J. Weller, B. Yanny, J. Zuntz

Research output: Contribution to journalArticle

184 Citations (Scopus)

Abstract

We present UV, optical, and near-infrared (NIR) photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo, the binary neutron star merger GW170817. Our data set extends from the discovery of the optical counterpart at 0.47-18.5 days post-merger, and includes observations with the Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), and the Hubble Space Telescope (HST). The spectral energy distribution (SED) inferred from this photometry at 0.6 days is well described by a blackbody model with T ≈ 8300 K, a radius of R ≈ 4.5 × 1014cm (corresponding to an expansion velocity of v ≈ 0.3c), and a bolometric luminosity of Lbol ≈ 5 × 1041 erg s-1. At 1.5 days we find a multi-component SED across the optical and NIR, and subsequently we observe rapid fading in the UV and blue optical bands and significant reddening of the optical/NIR colors. Modeling the entire data set, we find that models with heating from radioactive decay of 56Ni, or those with only a single component of opacity from r-process elements, fail to capture the rapid optical decline and red optical/NIR colors. Instead, models with two components consistent with lanthanide-poor and lanthanide-rich ejecta provide a good fit to the data; the resulting "blue" component has Mblue ej 0.1 M and vblue ej ≈ 0.3c, and the "red" component has and Mred ej ≈ 0.04 M⊙ and vred ej ≈ 0.1 c. These ejecta masses are broadly consistent with the estimated r-process production rate required to explain the Milky Way r-process abundances, providing the first evidence that binary neutron star (BNS) mergers can be a dominant site of r-process enrichment.

Original languageEnglish (US)
Article numberL17
JournalAstrophysical Journal Letters
Volume848
Issue number2
DOIs
StatePublished - Oct 20 2017

Fingerprint

LIGO (observatory)
binary stars
interferometer
merger
neutron stars
light curve
near infrared
observatory
laser
electromagnetism
ejecta
spectral energy distribution
rare earth element
energy
radioactive decay
color
infrared photometry
erg
fading
opacity

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. II. UV, Optical, and Near-infrared Light Curves and Comparison to Kilonova Models. / Cowperthwaite, P. S.; Berger, E.; Villar, V. A.; Metzger, B. D.; Nicholl, M.; Chornock, R.; Blanchard, P. K.; Fong, W.; Margutti, R.; Soares-Santos, M.; Alexander, K. D.; Allam, S.; Annis, J.; Brout, D.; Brown, Duncan; Butler, R. E.; Chen, H. Y.; Diehl, H. T.; Doctor, Z.; Drout, M. R.; Eftekhari, T.; Farr, B.; Finley, D. A.; Foley, R. J.; Frieman, J. A.; Fryer, C. L.; García-Bellido, J.; Gill, M. S.S.; Guillochon, J.; Herner, K.; Holz, D. E.; Kasen, D.; Kessler, R.; Marriner, J.; Matheson, T.; Neilsen, E. H.; Quataert, E.; Palmese, A.; Rest, A.; Sako, M.; Scolnic, D. M.; Smith, N.; Tucker, D. L.; Williams, P. K.G.; Balbinot, E.; Carlin, J. L.; Cook, E. R.; Durret, F.; Li, T. S.; Lopes, P. A.A.; Lourenço, A. C.C.; Marshall, J. L.; Medina, G. E.; Muir, J.; Muñoz, R. R.; Sauseda, M.; Schlegel, D. J.; Secco, L. F.; Vivas, A. K.; Wester, W.; Zenteno, A.; Zhang, Y.; Abbott, T. M.C.; Banerji, M.; Bechtol, K.; Benoit-Lévy, A.; Bertin, E.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Carrasco Kind, M.; Castander, F. J.; Crocce, M.; Cunha, C. E.; D'Andrea, C. B.; Costa, L. N.Da; Davis, C.; Depoy, D. L.; Desai, S.; Dietrich, J. P.; Drlica-Wagner, A.; Eifler, T. F.; Evrard, A. E.; Fernandez, E.; Flaugher, B.; Fosalba, P.; Gaztanaga, E.; Gerdes, D. W.; Giannantonio, T.; Goldstein, D. A.; Gruen, D.; Gruendl, R. A.; 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.; Nuropatkin, N.; Lahav, O.; Lima, M.; Lin, H.; Maia, M. A.G.; March, M.; Martini, P.; McMahon, R. G.; Menanteau, F.; Miller, C. J.; Miquel, R.; Mohr, J. J.; Neilsen, E.; Nichol, R. C.; Ogando, R. L.C.; Plazas, A. A.; Roe, N.; Romer, A. K.; Roodman, A.; Rykoff, E. S.; Sanchez, E.; Scarpine, V.; Schindler, R.; Schubnell, M.; Sevilla-Noarbe, I.; Smith, M.; Smith, R. C.; Sobreira, F.; Suchyta, E.; Swanson, M. E.C.; Tarle, G.; Thomas, D.; Thomas, R. C.; Troxel, M. A.; Vikram, V.; Walker, A. R.; Wechsler, R. H.; Weller, J.; Yanny, B.; Zuntz, J.

In: Astrophysical Journal Letters, Vol. 848, No. 2, L17, 20.10.2017.

Research output: Contribution to journalArticle

Cowperthwaite, PS, Berger, E, Villar, VA, Metzger, BD, Nicholl, M, Chornock, R, Blanchard, PK, Fong, W, Margutti, R, Soares-Santos, M, Alexander, KD, Allam, S, Annis, J, Brout, D, Brown, D, Butler, RE, Chen, HY, Diehl, HT, Doctor, Z, Drout, MR, Eftekhari, T, Farr, B, Finley, DA, Foley, RJ, Frieman, JA, Fryer, CL, García-Bellido, J, Gill, MSS, Guillochon, J, Herner, K, Holz, DE, Kasen, D, Kessler, R, Marriner, J, Matheson, T, Neilsen, EH, Quataert, E, Palmese, A, Rest, A, Sako, M, Scolnic, DM, Smith, N, Tucker, DL, Williams, PKG, Balbinot, E, Carlin, JL, Cook, ER, Durret, F, Li, TS, Lopes, PAA, Lourenço, ACC, Marshall, JL, Medina, GE, Muir, J, Muñoz, RR, Sauseda, M, Schlegel, DJ, Secco, LF, Vivas, AK, Wester, W, Zenteno, A, Zhang, Y, Abbott, TMC, Banerji, M, Bechtol, K, Benoit-Lévy, A, Bertin, E, Buckley-Geer, E, Burke, DL, Capozzi, D, Carnero Rosell, A, Carrasco Kind, M, Castander, FJ, Crocce, M, Cunha, CE, D'Andrea, CB, Costa, LND, Davis, C, Depoy, DL, Desai, S, Dietrich, JP, Drlica-Wagner, A, Eifler, TF, Evrard, AE, Fernandez, E, Flaugher, B, Fosalba, P, Gaztanaga, E, Gerdes, DW, Giannantonio, T, Goldstein, DA, Gruen, D, Gruendl, RA, Gutierrez, G, Honscheid, K, Jain, B, James, DJ, Jeltema, T, Johnson, MWG, Johnson, MD, Kent, S, Krause, E, Kron, R, Kuehn, K, Nuropatkin, N, Lahav, O, Lima, M, Lin, H, Maia, MAG, March, M, Martini, P, McMahon, RG, Menanteau, F, Miller, CJ, Miquel, R, Mohr, JJ, Neilsen, E, Nichol, RC, Ogando, RLC, Plazas, AA, Roe, N, Romer, AK, Roodman, A, Rykoff, ES, Sanchez, E, Scarpine, V, Schindler, R, Schubnell, M, Sevilla-Noarbe, I, Smith, M, Smith, RC, Sobreira, F, Suchyta, E, Swanson, MEC, Tarle, G, Thomas, D, Thomas, RC, Troxel, MA, Vikram, V, Walker, AR, Wechsler, RH, Weller, J, Yanny, B & Zuntz, J 2017, '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', Astrophysical Journal Letters, vol. 848, no. 2, L17. https://doi.org/10.3847/2041-8213/aa8fc7
Cowperthwaite, P. S. ; Berger, E. ; Villar, V. A. ; Metzger, B. D. ; Nicholl, M. ; Chornock, R. ; Blanchard, P. K. ; Fong, W. ; Margutti, R. ; Soares-Santos, M. ; Alexander, K. D. ; Allam, S. ; Annis, J. ; Brout, D. ; Brown, Duncan ; Butler, R. E. ; Chen, H. Y. ; Diehl, H. T. ; Doctor, Z. ; Drout, M. R. ; Eftekhari, T. ; Farr, B. ; Finley, D. A. ; Foley, R. J. ; Frieman, J. A. ; Fryer, C. L. ; García-Bellido, J. ; Gill, M. S.S. ; Guillochon, J. ; Herner, K. ; Holz, D. E. ; Kasen, D. ; Kessler, R. ; Marriner, J. ; Matheson, T. ; Neilsen, E. H. ; Quataert, E. ; Palmese, A. ; Rest, A. ; Sako, M. ; Scolnic, D. M. ; Smith, N. ; Tucker, D. L. ; Williams, P. K.G. ; Balbinot, E. ; Carlin, J. L. ; Cook, E. R. ; Durret, F. ; Li, T. S. ; Lopes, P. A.A. ; Lourenço, A. C.C. ; Marshall, J. L. ; Medina, G. E. ; Muir, J. ; Muñoz, R. R. ; Sauseda, M. ; Schlegel, D. J. ; Secco, L. F. ; Vivas, A. K. ; Wester, W. ; Zenteno, A. ; Zhang, Y. ; Abbott, T. M.C. ; Banerji, M. ; Bechtol, K. ; Benoit-Lévy, A. ; Bertin, E. ; Buckley-Geer, E. ; Burke, D. L. ; Capozzi, D. ; Carnero Rosell, A. ; Carrasco Kind, M. ; Castander, F. J. ; Crocce, M. ; Cunha, C. E. ; D'Andrea, C. B. ; Costa, L. N.Da ; Davis, C. ; Depoy, D. L. ; Desai, S. ; Dietrich, J. P. ; Drlica-Wagner, A. ; Eifler, T. F. ; Evrard, A. E. ; Fernandez, E. ; Flaugher, B. ; Fosalba, P. ; Gaztanaga, E. ; Gerdes, D. W. ; Giannantonio, T. ; Goldstein, D. A. ; Gruen, D. ; Gruendl, R. A. ; 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. ; Nuropatkin, N. ; Lahav, O. ; Lima, M. ; Lin, H. ; Maia, M. A.G. ; March, M. ; Martini, P. ; McMahon, R. G. ; Menanteau, F. ; Miller, C. J. ; Miquel, R. ; Mohr, J. J. ; Neilsen, E. ; Nichol, R. C. ; Ogando, R. L.C. ; Plazas, A. A. ; Roe, N. ; Romer, A. K. ; Roodman, A. ; Rykoff, E. S. ; Sanchez, E. ; Scarpine, V. ; Schindler, R. ; Schubnell, M. ; Sevilla-Noarbe, I. ; Smith, M. ; Smith, R. C. ; Sobreira, F. ; Suchyta, E. ; Swanson, M. E.C. ; Tarle, G. ; Thomas, D. ; Thomas, R. C. ; Troxel, M. A. ; Vikram, V. ; Walker, A. R. ; Wechsler, R. H. ; Weller, J. ; Yanny, B. ; Zuntz, J. / 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. In: Astrophysical Journal Letters. 2017 ; Vol. 848, No. 2.
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title = "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",
abstract = "We present UV, optical, and near-infrared (NIR) photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo, the binary neutron star merger GW170817. Our data set extends from the discovery of the optical counterpart at 0.47-18.5 days post-merger, and includes observations with the Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), and the Hubble Space Telescope (HST). The spectral energy distribution (SED) inferred from this photometry at 0.6 days is well described by a blackbody model with T ≈ 8300 K, a radius of R ≈ 4.5 × 1014cm (corresponding to an expansion velocity of v ≈ 0.3c), and a bolometric luminosity of Lbol ≈ 5 × 1041 erg s-1. At 1.5 days we find a multi-component SED across the optical and NIR, and subsequently we observe rapid fading in the UV and blue optical bands and significant reddening of the optical/NIR colors. Modeling the entire data set, we find that models with heating from radioactive decay of 56Ni, or those with only a single component of opacity from r-process elements, fail to capture the rapid optical decline and red optical/NIR colors. Instead, models with two components consistent with lanthanide-poor and lanthanide-rich ejecta provide a good fit to the data; the resulting {"}blue{"} component has Mblue ej 0.1 M⊙ and vblue ej ≈ 0.3c, and the {"}red{"} component has and Mred ej ≈ 0.04 M⊙ and vred ej ≈ 0.1 c. These ejecta masses are broadly consistent with the estimated r-process production rate required to explain the Milky Way r-process abundances, providing the first evidence that binary neutron star (BNS) mergers can be a dominant site of r-process enrichment.",
keywords = "binaries: close, catalogs, gravitational waves, stars: neutron, surveys",
author = "Cowperthwaite, {P. S.} and E. Berger and Villar, {V. A.} and Metzger, {B. D.} and M. Nicholl and R. Chornock and Blanchard, {P. K.} and W. Fong and R. Margutti and M. Soares-Santos and Alexander, {K. D.} and S. Allam and J. Annis and D. Brout and Duncan Brown and Butler, {R. E.} and Chen, {H. Y.} and Diehl, {H. T.} and Z. Doctor and Drout, {M. R.} and T. Eftekhari and B. Farr and Finley, {D. A.} and Foley, {R. J.} and Frieman, {J. A.} and Fryer, {C. L.} and J. Garc{\'i}a-Bellido and Gill, {M. S.S.} and J. Guillochon and K. Herner and Holz, {D. E.} and D. Kasen and R. Kessler and J. Marriner and T. Matheson and Neilsen, {E. H.} and E. Quataert and A. Palmese and A. Rest and M. Sako and Scolnic, {D. M.} and N. Smith and Tucker, {D. L.} and Williams, {P. K.G.} and E. Balbinot and Carlin, {J. L.} and Cook, {E. R.} and F. Durret and Li, {T. S.} and Lopes, {P. A.A.} and Louren{\cc}o, {A. C.C.} and Marshall, {J. L.} and Medina, {G. E.} and J. Muir and Mu{\~n}oz, {R. R.} and M. Sauseda and Schlegel, {D. J.} and Secco, {L. F.} and Vivas, {A. K.} and W. Wester and A. Zenteno and Y. Zhang and Abbott, {T. M.C.} and M. Banerji and K. Bechtol and A. Benoit-L{\'e}vy and E. Bertin and E. Buckley-Geer and Burke, {D. L.} and D. Capozzi and {Carnero Rosell}, A. and {Carrasco Kind}, M. 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 Depoy, {D. L.} and S. Desai and Dietrich, {J. P.} and A. Drlica-Wagner and Eifler, {T. F.} and Evrard, {A. E.} 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 Gruendl, {R. A.} 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 N. Nuropatkin and O. Lahav and M. Lima and H. Lin and Maia, {M. A.G.} and M. March and P. Martini and McMahon, {R. G.} and F. Menanteau and Miller, {C. J.} and R. Miquel and Mohr, {J. J.} and E. Neilsen and Nichol, {R. C.} and Ogando, {R. L.C.} and Plazas, {A. A.} and N. Roe and Romer, {A. K.} and A. Roodman and Rykoff, {E. S.} and E. Sanchez and V. Scarpine and R. Schindler and M. Schubnell and I. Sevilla-Noarbe and M. Smith and Smith, {R. C.} and F. Sobreira 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 Walker, {A. R.} and Wechsler, {R. H.} and J. Weller and B. Yanny and J. Zuntz",
year = "2017",
month = "10",
day = "20",
doi = "10.3847/2041-8213/aa8fc7",
language = "English (US)",
volume = "848",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
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}

TY - JOUR

T1 - 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

AU - Cowperthwaite, P. S.

AU - Berger, E.

AU - Villar, V. A.

AU - Metzger, B. D.

AU - Nicholl, M.

AU - Chornock, R.

AU - Blanchard, P. K.

AU - Fong, W.

AU - Margutti, R.

AU - Soares-Santos, M.

AU - Alexander, K. D.

AU - Allam, S.

AU - Annis, J.

AU - Brout, D.

AU - Brown, Duncan

AU - Butler, R. E.

AU - Chen, H. Y.

AU - Diehl, H. T.

AU - Doctor, Z.

AU - Drout, M. R.

AU - Eftekhari, T.

AU - Farr, B.

AU - Finley, D. A.

AU - Foley, R. J.

AU - Frieman, J. A.

AU - Fryer, C. L.

AU - García-Bellido, J.

AU - Gill, M. S.S.

AU - Guillochon, J.

AU - Herner, K.

AU - Holz, D. E.

AU - Kasen, D.

AU - Kessler, R.

AU - Marriner, J.

AU - Matheson, T.

AU - Neilsen, E. H.

AU - Quataert, E.

AU - Palmese, A.

AU - Rest, A.

AU - Sako, M.

AU - Scolnic, D. M.

AU - Smith, N.

AU - Tucker, D. L.

AU - Williams, P. K.G.

AU - Balbinot, E.

AU - Carlin, J. L.

AU - Cook, E. R.

AU - Durret, F.

AU - Li, T. S.

AU - Lopes, P. A.A.

AU - Lourenço, A. C.C.

AU - Marshall, J. L.

AU - Medina, G. E.

AU - Muir, J.

AU - Muñoz, R. R.

AU - Sauseda, M.

AU - Schlegel, D. J.

AU - Secco, L. F.

AU - Vivas, A. K.

AU - Wester, W.

AU - Zenteno, A.

AU - Zhang, Y.

AU - Abbott, T. M.C.

AU - Banerji, M.

AU - Bechtol, K.

AU - Benoit-Lévy, A.

AU - Bertin, E.

AU - Buckley-Geer, E.

AU - Burke, D. L.

AU - Capozzi, D.

AU - Carnero Rosell, A.

AU - Carrasco Kind, M.

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 - Depoy, D. L.

AU - Desai, S.

AU - Dietrich, J. P.

AU - Drlica-Wagner, A.

AU - Eifler, T. F.

AU - Evrard, A. E.

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 - Gruendl, R. A.

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 - Nuropatkin, N.

AU - Lahav, O.

AU - Lima, M.

AU - Lin, H.

AU - Maia, M. A.G.

AU - March, M.

AU - Martini, P.

AU - McMahon, R. G.

AU - Menanteau, F.

AU - Miller, C. J.

AU - Miquel, R.

AU - Mohr, J. J.

AU - Neilsen, E.

AU - Nichol, R. C.

AU - Ogando, R. L.C.

AU - Plazas, A. A.

AU - Roe, N.

AU - Romer, A. K.

AU - Roodman, A.

AU - Rykoff, E. S.

AU - Sanchez, E.

AU - Scarpine, V.

AU - Schindler, R.

AU - Schubnell, M.

AU - Sevilla-Noarbe, I.

AU - Smith, M.

AU - Smith, R. C.

AU - Sobreira, F.

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 - Walker, A. R.

AU - Wechsler, R. H.

AU - Weller, J.

AU - Yanny, B.

AU - Zuntz, J.

PY - 2017/10/20

Y1 - 2017/10/20

N2 - We present UV, optical, and near-infrared (NIR) photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo, the binary neutron star merger GW170817. Our data set extends from the discovery of the optical counterpart at 0.47-18.5 days post-merger, and includes observations with the Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), and the Hubble Space Telescope (HST). The spectral energy distribution (SED) inferred from this photometry at 0.6 days is well described by a blackbody model with T ≈ 8300 K, a radius of R ≈ 4.5 × 1014cm (corresponding to an expansion velocity of v ≈ 0.3c), and a bolometric luminosity of Lbol ≈ 5 × 1041 erg s-1. At 1.5 days we find a multi-component SED across the optical and NIR, and subsequently we observe rapid fading in the UV and blue optical bands and significant reddening of the optical/NIR colors. Modeling the entire data set, we find that models with heating from radioactive decay of 56Ni, or those with only a single component of opacity from r-process elements, fail to capture the rapid optical decline and red optical/NIR colors. Instead, models with two components consistent with lanthanide-poor and lanthanide-rich ejecta provide a good fit to the data; the resulting "blue" component has Mblue ej 0.1 M⊙ and vblue ej ≈ 0.3c, and the "red" component has and Mred ej ≈ 0.04 M⊙ and vred ej ≈ 0.1 c. These ejecta masses are broadly consistent with the estimated r-process production rate required to explain the Milky Way r-process abundances, providing the first evidence that binary neutron star (BNS) mergers can be a dominant site of r-process enrichment.

AB - We present UV, optical, and near-infrared (NIR) photometry of the first electromagnetic counterpart to a gravitational wave source from Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo, the binary neutron star merger GW170817. Our data set extends from the discovery of the optical counterpart at 0.47-18.5 days post-merger, and includes observations with the Dark Energy Camera (DECam), Gemini-South/FLAMINGOS-2 (GS/F2), and the Hubble Space Telescope (HST). The spectral energy distribution (SED) inferred from this photometry at 0.6 days is well described by a blackbody model with T ≈ 8300 K, a radius of R ≈ 4.5 × 1014cm (corresponding to an expansion velocity of v ≈ 0.3c), and a bolometric luminosity of Lbol ≈ 5 × 1041 erg s-1. At 1.5 days we find a multi-component SED across the optical and NIR, and subsequently we observe rapid fading in the UV and blue optical bands and significant reddening of the optical/NIR colors. Modeling the entire data set, we find that models with heating from radioactive decay of 56Ni, or those with only a single component of opacity from r-process elements, fail to capture the rapid optical decline and red optical/NIR colors. Instead, models with two components consistent with lanthanide-poor and lanthanide-rich ejecta provide a good fit to the data; the resulting "blue" component has Mblue ej 0.1 M⊙ and vblue ej ≈ 0.3c, and the "red" component has and Mred ej ≈ 0.04 M⊙ and vred ej ≈ 0.1 c. These ejecta masses are broadly consistent with the estimated r-process production rate required to explain the Milky Way r-process abundances, providing the first evidence that binary neutron star (BNS) mergers can be a dominant site of r-process enrichment.

KW - binaries: close

KW - catalogs

KW - gravitational waves

KW - stars: neutron

KW - surveys

UR - http://www.scopus.com/inward/record.url?scp=85031911574&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85031911574&partnerID=8YFLogxK

U2 - 10.3847/2041-8213/aa8fc7

DO - 10.3847/2041-8213/aa8fc7

M3 - Article

VL - 848

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 2

M1 - L17

ER -