@inproceedings{3b2a35d01afb4a38a75e8cafca252d2b,
title = "X-ray flare in XRF 050406: Evidence for prolonged engine activity",
abstract = "We present observations of XRF 050406, an X-ray flash with a relatively low fluence (∼ 10-7 erg cm-2 in the 15-350 keV band), a soft spectrum (photon index Γγ = 2.65), no significant flux above ∼ 50 keV and a peak energy Ep < 15 keV. XRF 050406 is the first burst detected by Swift clearly showing a flare in its X-ray light curve. The flare peaks 210 s after the BAT trigger, presents a flux variation δF/F ∼ 6 in a timescale δt/tpeak ≪ 1 and a measured fluence of 1-15% of the prompt one. We argue that the producing mechanism is late internal shocks, which implies that the central engine is still active at 210 s, though with a reduced power with respect to the prompt emission. The X-ray light curve flattens to a more shallow slope with a decay index of ∼ 0.5 after ∼ 4400 s, also supporting continued central engine activity.",
author = "P. Romano and A. Moretti and Banat, {P. L.} and Burrows, {D. N.} and S. Campana and G. Chincarini and S. Covino and D. Malesani and G. Tagliaferri and Falcone, {A. D.} and M. Capalbi and G. Cusumano and P. Giommi and {La Parola}, V. and V. Mangano and M. Perri and C. Pagani",
note = "Copyright: Copyright 2008 Elsevier B.V., All rights reserved.; GAMMA-RAY BURSTS IN THE SWIFT ERA: 16th Maryland Astrophysics Conference ; Conference date: 29-11-2005 Through 02-12-2005",
year = "2006",
month = may,
day = "19",
doi = "10.1063/1.2207956",
language = "English (US)",
isbn = "0735403260",
series = "AIP Conference Proceedings",
pages = "570--573",
booktitle = "GAMMA-RAY BURSTS IN THE SWIFT ERA",
}