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 Academic Article uri icon


  • 2017. The American Astronomical Society. All rights reserved.. 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 Mblueej 0.1 M and vblueej 0.3c, and the "red" component has and Mredej 0.04 M and vredej 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.

published proceedings


altmetric score

  • 51.86

author list (cited authors)

  • Cowperthwaite, P. S., Berger, E., Villar, V. A., Metzger, B. D., Nicholl, M., Chornock, R., ... Zuntz, J.

citation count

  • 663

complete list of authors

  • 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, DA||Butler, RE||Chen, H-Y||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, LN da||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

publication date

  • October 2017