Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The diversity of progenitors and emission mechanisms for ultra-long
  bursts   GRB 111209A is the longest ever recorded burst. This burst was detected by
Swift and Konus-Wind, and we obtained TOO time from XMM-Newton as well as
prompt data from TAROT. We made a common reduction using data from these
instruments together with other ones. This allows for the first time a precise
study at high signal-to-noise ratio of the prompt to afterglow transition. We
show that several mechanisms are responsible of this phase. In its prompt
phase, we show that its duration is longer than 20 000 seconds. This, combined
with the fact that the burst fluence is among the top 5% of what is observed
for other events, makes this event extremely energetic. We discuss the possible
progenitors that could explain the extreme duration properties of this burst as
well as its spectral properties. We present evidences that this burst belong to
a new, previously unidentified, class of GRBs. The most probable progenitor of
this new class is a low metalicity blue super-giant star. We show that
selection effects could prevent the detection of other bursts at larger
redshift and conclude that this kind of event is intrinsically rare in the
local Universe. The afterglow presents similar features to other normal long
GRBs and a late rebrightening in the optical wavelengths, as observed in other
long GRBs. A broad band SED from radio to X-rays at late times does not show
significant deviations from the expected standard fireball afterglow
synchrotron emission.

14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol