The First Survey of X‐Ray Flares from Gamma‐Ray Bursts Observed bySwift: Temporal Properties and Morphology

• DOI: 10.1086/521591
• Publication Date: 2007-12-20T00:32:46Z
• Authors: G. Chincarini; A. Moretti; P. Romano; A. D. Falcone; D. Morris; J. Racusin; S. Campana; S. Covino; C. Guidorzi; G. Tagliaferri; D. N. Burrows; C. Pagani; M. Stroh; D. Grupe; M. Capalbi; G. Cusumano; N. Gehrels; P. Giommi; V. La Parola; V. Mangano; T. Mineo; J. A. Nousek; P. T. O’Brien; K. L. Page; M. Perri; E. Troja; R. Willingale; B. Zhang
• Keywords: Flare; Swift

We present the first systematic investigation of morphological and timing properties flares in GRBs observed by Swift XRT. consider a large sample drawn from all detected Swift, INTEGRAL, HETE-2 prior to 2006 January 31, which had an XRT follow-up showed significant flaring. Our 33 includes long short, at low high redshift, total 69 flares. The strongest occur early phases, with clear anticorrelation between flare peak intensity time occurrence. Fitting each X-ray Gaussian model, we find that mean ratio width is ⟨ Δ t/t⟩ = 0.13 ± 0.10, albeit scatter. Late times >2000 s have durations, t > 300 s, can be very energetic compared underlying continuum. further investigated whether there link number pulses prompt phase BAT XRT, finding no correlation. However, distribution ratios successive same, indication common origin for gamma-ray All evidence indicates are indeed related workings central engine and, standard fireball scenario, originate internal shocks rather than external shocks. While explained long-lasting activity, 29/69 may also refreshed 10 only prolonged activity engine.