| Title | Early spectra of the gravitational wave source GW170817: Evolution of a neutron star merger. |
| Publication Type | Journal Article |
| Year of Publication | 2017 |
| Authors | Shappee BJ, Simon JD, Drout MR, Piro AL, Morrell N, Prieto JL, Kasen D, Holoien TW-S, Kollmeier JA, Kelson DD, Coulter DA, Foley RJ, Kilpatrick CD, Siebert MR, Madore BF, Murguia-Berthier A, Pan Y-C, Prochaska JX, Ramirez-Ruiz E, Rest A, Adams C, Alatalo K, Bañados E, Baughman J, Bernstein RA, Bitsakis T, Boutsia K, Bravo JR, Di Mille F, Higgs CR, Ji AP, Maravelias G, Marshall JL, Placco VM, Prieto G, Wan Z |
| Journal | Science |
| Volume | 358 |
| Issue | 6370 |
| Pagination | 1574-1578 |
| Date Published | 2017 12 22 |
| ISSN | 1095-9203 |
| Abstract | On 17 August 2017, Swope Supernova Survey 2017a (SSS17a) was discovered as the optical counterpart of the binary neutron star gravitational wave event GW170817. We report time-series spectroscopy of SSS17a from 11.75 hours until 8.5 days after the merger. Over the first hour of observations, the ejecta rapidly expanded and cooled. Applying blackbody fits to the spectra, we measured the photosphere cooling from [Formula: see text] to [Formula: see text] kelvin, and determined a photospheric velocity of roughly 30% of the speed of light. The spectra of SSS17a began displaying broad features after 1.46 days and evolved qualitatively over each subsequent day, with distinct blue (early-time) and red (late-time) components. The late-time component is consistent with theoretical models of r-process-enriched neutron star ejecta, whereas the blue component requires high-velocity, lanthanide-free material. |
| DOI | 10.1126/science.aaq0186 |
| Alternate Journal | Science |
| PubMed ID | 29038374 |
Submitted by kej2006 on June 6, 2018 - 4:12pm