Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Decline in the X-ray through Radio Emission from GW170817 Continues to
  Support an Off-Axis Structured Jet   We present new observations of the binary neutron star merger GW170817 at
$\Delta t\approx 220-290$ 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 $\gtrsim5\sigma$ significance. The radio-to-X-ray spectral energy
distribution exhibits no evolution into the declining phase. Our full
multi-wavelength dataset 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 $\sim
1000$ days post-merger.

28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
2
The categories of this paper are: math
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
5
The categories of this paper are: gr-qc