@article{bc57509085b241299314ccbfa1271fa2,
title = "GRB 080407: An ultra-long burst discovered by the IPN",
abstract = "We present observations of the extremely long GRB 080704 obtained with the instruments of the Interplanetary Network (IPN). The observations reveal two distinct emission episodes, separated by a -1500 s long period of quiescence. The total burst duration is about 2100 s. We compare the temporal and spectral characteristics of this burst with those obtained for other ultra-long GRBs and discuss these characteristics in the context of different models.",
author = "V. Pal{\textquoteright}shin and K. Hurley and J. Goldsten and Mitrofanov, {I. G.} and W. Boynton and {Von Kienlin}, A. and J. Cummings and M. Feroci and R. Aptekar and D. Frederiks and S. Golenetskii and E. Mazets and D. Svinkin and D. Golovin and Litvak, {M. L.} and Sanin, {A. B.} and C. Fellows and K. Harshman and R. Starr and A. Rau and X. Zhang and V. Savchenko and Barthelmy, {S. D.} and N. Gehrels and H. Krimm and D. Palmer and {Del Monte}, E. and M. Marisaldi",
note = "Funding Information: Only a few ultra-long GRBs (with durations > 1000 s) have been reported to date. We have presented observations of GRB 080407, probably the longest multi-episode GRB detected so far. The measured burst fluence of ∼ 4 × 10−4 erg cm−2 (20–1000 keV) is among the largest observed in long GRBs. This burst demonstrates similarities with other ultra-long bursts: a long quiescent time between the episodes (∼1500 s), spectral evolution from hard initial pulse to significantly softer subsequent pulses, and a large fluence. The duration of the second emission episode of GRB 080704 (following the quiescent time) is substantially longer that the duration of the first episode, which is a common feature of long GRBs. The existence of such long quiescent times may favor the dormant inner engine scenario over wind modulation models [2]. Without knowledge of the burst redshift it is not possible to determine the rest frame properties of the burst, but its large fluence and high Epeak suggest a moderate z of ∼1–2 (for z=1 Eiso ∼ 1.2 × 1054 erg). In such a case, the rest frame burst duration of ∼1000 s and the rest frame quiescence time of ∼500 s can pose a problem for some central engine models in the framework of the collapsar scenario. Specifically such long durations might be hard to explain in the magnetar model of long GRBs. The Konus-Wind experiment is supported by a Russian Space Agency contract and RFBR grant 12-02-00032a. KH is grateful for IPN support under the following NASA grants: NNX07AR71G (MESSENGER), NNX08AN23G (Swift), and NNX08AC90G (INTEGRAL). Publisher Copyright: {\textcopyright} Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.; 2012 Gamma-Ray Bursts Conference, GRB 2012 ; Conference date: 07-05-2012 Through 11-05-2012",
year = "2012",
language = "English (US)",
volume = "2012-May",
journal = "Proceedings of Science",
issn = "1824-8039",
publisher = "Sissa Medialab Srl",
}