Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Is the line-like optical afterglow SED of GRB 050709 due to a flare?   Recently Jin et al. (2016) reanalyzed the optical observation data of GRB
050709 and reported a line-like spectral energy distribution (SED) component
observed by the Very Large Telescope at $t\sim 2.5$ days after the trigger of
the burst, which had been interpreted as a broadened line signal arising from a
macronova dominated by iron group. In this work we show that an optical flare
origin of such a peculiar optical SED is still possible. Interestingly, even in
such a model, an "unusual" origin of the late-time long-lasting Hubble Space
Telescope F814W-band emission is still needed and a macronova/kilonova is the
natural interpretation.

9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
1
The categories of this paper are: cs
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat
12
The categories of this paper are: nucl-th