X-ray Flares in Early GRB Afterglows

Abstract

The Swift X-ray Telescope (XRT) has discovered that flares are quite common in early X-ray afterglows of Gamma-Ray Bursts (GRBs), being observed in roughly 50% of afterglows with prompt followup observations. The flares range in fluence from a few percent to ~ 100% of the fluence of the prompt emission (the GRB). Repetitive flares are seen, with more than 4 successive flares detected by the XRT in some afterglows. The rise and fall times of the flares are typically considerably smaller than the time since the burst. These characteristics suggest that the flares are related to the prompt emission mechanism, but at lower photon energies. We conclude that the most likely cause of these flares is late-time activity of the GRB central engine.

Accepted for publication in Philosophical Transactions A. 12 pages

References in corpus (33)

• The Swift X-ray Telescope
• The Swift Ultra-Violet/Optical Telescope
• The Burst Alert Telescope (BAT) on the Swift MIDEX Mission
• Unsteady Outflow Models for Cosmological Gamma-Ray Bursts
• Physical processes shaping GRB X-ray afterglow lightcurves: theoretical implications from the Swift XRT observations
• Discovery of the X-Ray Afterglow of the Gamma-Ray Burst of February 28 1997
• Evidence for a Canonical GRB Afterglow Light Curve in the Swift/XRT Data
• Theories of Gamma-Ray Bursts
• Bright X-ray Flares in Gamma-Ray Burst Afterglows
• Afterglow Emission from Naked Gamma-Ray Bursts
• The early X-ray emission from GRBs
• An origin for short g-ray bursts unassociated with current star formation
• Panchromatic study of GRB 060124: from precursor to afterglow
• BATSE Observations of Gamma-Ray Burst Spectra. II. Peak Energy Evolution in Bright, Long Bursts -
• Testing the Curvature Effect and Internal Origin of Gamma-Ray Burst Prompt Emissions and X-ray Flares with Swift Data
• Prompt and delayed emission properties of Gamma-Ray Bursts observed with BeppoSAX
• Variabilities of Gamma-Ray Burst Afterglows: Long-acting Engine, Anisotropic Jet or Many Fluctuating Regions?
• The Giant X-ray Flare of GRB 050502B: Evidence for Late-Time Internal Engine Activity
• Jet Breaks in Short Gamma-Ray Bursts. II: The Collimated Afterglow of GRB 051221A
• Analysis of the X-ray Emission of Nine Swift Afterglows
• Probing the environment in Gamma-ray bursts: the case of an X-ray precursor, afterglow late onset and wind vs constant density profile in GRB011121 and GRB011211
• Jet Breaks in Short Gamma-Ray Bursts. I: The Uncollimated Afterglow of GRB 050724
• X-ray flare in XRF 050406: evidence for prolonged engine activity
• Multi-Wavelength Observations of GRB 050820A: An Exceptionally Energetic Event Followed from Start to Finish
• The X-ray afterglow of the short gamma ray burst 050724
• Gas and dust properties in the afterglow spectra of GRB 050730
• Detection of a huge explosion in the early Universe
• Outshining the quasars at reionisation: The X-ray spectrum and lightcurve of the redshift 6.29 Gamma-Ray Burst GRB050904
• GRB051210: Swift detection of a short gamma ray burst
• Gamma-ray burst afterglows
• The Swift X-ray flaring afterglow of GRB 050607
• GRB 050117: Simultaneous Gamma-ray and X-ray Observations with the Swift Satellite
• GRBs with the Swift satellite

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• X-ray flares, plateaus, and chromatic breaks of GRB afterglows from up-scattered forward-shock emission
• GRB 060714: No Clear Dividing Line Between Prompt Emission and X-ray Flares
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• Thermal components in the early X-ray afterglows of GRBs: likely cocoon emission and constraints on the progenitors
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• The in-flight spectroscopic performance of the Swift XRT CCD camera during 2006-2007
• Search for muon neutrinos from Gamma-Ray Bursts with the IceCube neutrino telescope
• Gamma Ray Bursts: basic facts and ideas
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