HETE-2 Observations of the X-Ray Flash XRF 040916

Abstract

A long X-ray flash was detected and localized by the instruments aboard the High Energy Transient Explorer II (HETE-2) at 00:03:30 UT on 2004 September 16. The position was reported to the GRB Coordinates Network (GCN) approximately 2 hours after the burst. This burst consists of two peaks separated by 200 s, with durations of 110 s and 60 s. We have analyzed the energy spectra of the 1st and 2nd peaks observed with the Wide Field X-Ray Monitor (WXM) and the French Gamma Telescope (FREGATE). We discuss the origin of the 2nd peak in terms of flux variabilities and timescales. We find that it is most likely part of the prompt emission, and is explained by the long-acting engine model. This feature is similar to some bright X-ray flares detected in the early afterglow phase of bursts observed by the Swift satellite.

9 pages, 4 figures, Accepted for publication in PASJ

References in corpus (5)

• Testing the Curvature Effect and Internal Origin of Gamma-Ray Burst Prompt Emissions and X-ray Flares with Swift Data
• The Giant X-ray Flare of GRB 050502B: Evidence for Late-Time Internal Engine Activity
• X-ray flare in XRF 050406: evidence for prolonged engine activity
• Small-scale variations in the radiating surface of the GRB 011211 jet
• An improved redshift indicator for Gamma-Ray Bursts, based on the prompt emission

Cited by in corpus (3)

• GRB X-Ray Flare Properties among Different GRB Subclasses
• GRB Optical and X-ray Plateau Properties Classifier Using Unsupervised Machine Learning
• Late Engine Activity of GRB 161017A Revealed by Early Optical Observations