@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 = "Funding Information: Acknowledgements. We thank the Natural Sciences and Engineering Research Council of Canada for financial support. An NSERC Postdoctoral Fellowship (YJW), an Alberta Heritage Foundation for Medical Research Graduate Fellowship (SMB), an FCAR (Quebec) Postdoctoral Fellowship (LB), an FCAR (Quebec) Graduate Fellowship (MC) , an NSERC Summer Undergraduate Award (GK^^)^ ^nd AHFMR Summer Undergraduate Awards (CJN,^^ SRR^^) Q^^^Q gratefully acknowledged. CNB was a High School research participant. We thank H. W. Manning (U of A) and Professor E. Vedejs for advice; D. Lucyk,^^ ]\j^ Khazanovich, ^2 p^ Sartorelli, ^2 ^nd Dr. C. Lowe for assistance; and Dr. S. Forenza (Bristol-Myers Squibb) and Dr. M. Suffness (NIH) for samples of natural 1 and its potassium salt, respectively.; 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",
}