A Decline in the X-Ray through Radio Emission from GW170817 Continues to Support an Off-axis Structured Jet

作者：Alexander K D^*; Margutti R; Blanchard P K; Fong W; Berger E; Hajela A; Eftekhari T; Chornock R; Cowperthwaite P S; Giannios D; Guidorzi C; Kathirgamaraju A; MacFadyen A; Metzger B D; Nicholl M; Sironi L; Villar V A; Williams P K G; Xie X; Zrake J

来源：Astrophysical Journal Letters, 2018, 863(2): L18.

DOI：10.3847/2041-8213/aad637

• gravitational waves
• relativistic processes

We present new observations of the binary neutron star merger GW170817 at Delta t approximate to 220-290 days post-merger, at radio (Karl G. Jansky Very Large Array; VLA), X-ray (Chandra X-ray Observatory), and optical (Hubble Space Telescope; HST) wavelengths. These observations provide the first evidence for a turnover in the X-ray light curve, mirroring a decline in the radio emission at greater than or similar to 5 sigma significance. The radio-to-X-ray spectral energy distribution exhibits no evolution into the declining phase. Our full multi-wavelength data set is consistent with the predicted behavior of our previously published models of a successful structured jet expanding into a low-density circumbinary medium, but pure cocoon models with a choked jet cannot be ruled out. If future observations continue to track our predictions, we expect that the radio and X-ray emission will remain detectable until similar to 1000 days post-merger.

• 出版日期2018-8-20
• 单位西北大学