Details

Autor(en) / Beteiligte

• Lamb, G. P.
• Tanvir, N. R.
• Levan, A. J.
• Postigo, A. de Ugarte
• Kawaguchi, K.
• Corsi, A.
• Evans, P. A.
• Gompertz, B.
• Malesani, D. B.
• Page, K. L.
• Wiersema, K.
• Rosswog, S.
• Shibata, M.
• Tanaka, M.
• Horst, A. J. van der
• Cano, Z.
• Fynbo, J. P. U.
• Fruchter, A. S.
• Greiner, J.
• Heintz, K. E.
• Higgins, A.
• Hjorth, J.
• Izzo, L.
• Jakobsson, P.
• Kann, D. A.
• O'Brien, P. T.
• Perley, D. A.
• Pian, E.
• Pugliese, G.
• Starling, R. L. C.
• Thöne, C. C.
• Watson, D.
• Wijers, R. A. M. J.
• Xu, D.

Titel

Short GRB 160821B: A Reverse Shock, a Refreshed Shock, and a Well-sampled Kilonova

Ist Teil von

• The Astrophysical journal, 2019-09, Vol.883 (1), p.48

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2019

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• We report our identification of the optical afterglow and host galaxy of the short-duration gamma-ray burst sGRB 160821B. The spectroscopic redshift of the host is z = 0.162, making it one of the lowest redshift short-duration gamma-ray bursts (sGRBs) identified by Swift. Our intensive follow-up campaign using a range of ground-based facilities as well as Hubble Space Telescope, XMM-Newton, and Swift, shows evidence for a late-time excess of optical and near-infrared emission in addition to a complex afterglow. The afterglow light curve at X-ray frequencies reveals a narrow jet, deg, that is refreshed at >1 day post-burst by a slower outflow with significantly more energy than the initial outflow that produced the main GRB. Observations of the 5 GHz radio afterglow shows a reverse shock into a mildly magnetized shell. The optical and near-infrared excess is fainter than AT2017gfo associated with GW170817, and is well explained by a kilonova with dynamic ejecta mass Mdyn = (1.0 0.6) × 10−3 M and a secular (post-merger) ejecta mass with Mpm = (1.0 0.6) × 10−2 M , consistent with a binary neutron star merger resulting in a short-lived massive neutron star. This optical and near-infrared data set provides the best-sampled kilonova light curve without a gravitational wave trigger to date.