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

Autor: 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, 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
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Cowperthwaite, PS; Berger, E; Villar, VA; Metzger, BD; Nicholl, M; Chornock, R; et al.(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, 848(2). doi: 10.3847/2041-8213/aa8fc7. UC Berkeley: Retrieved from: http://www.escholarship.org/uc/item/0wc6v6pt
Popis: © 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 × 1041erg 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 of56Ni, 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 Mblueej0.1 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.
Databáze: OpenAIRE