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Updated: Jul 17, 2026
15:04
Rejection of Fluorescence Background in Resonance and Spontaneous Raman Microspectroscopy
Published on: May 18, 2011
X-ray flares in early GRB afterglows
D N Burrows1, A Falcone, G Chincarini
1Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA. dxb15@psu.edu
Summary
Flares are common in early gamma-ray burst (GRB) afterglows, observed in about 50% of cases. These repetitive X-ray flares likely stem from late-time activity of the GRB central engine.
Area of Science:
- High-energy astrophysics
- Gamma-ray burst (GRB) afterglow studies
- X-ray astronomy
Background:
- Flares are frequently observed in the early X-ray afterglows of gamma-ray bursts (GRBs).
- These flares exhibit a wide range of fluences, from a few percent to the total fluence of the prompt GRB emission.
- Repetitive flaring activity, with multiple successive flares, has been detected.
Purpose of the Study:
- To investigate the commonality and characteristics of flares in early X-ray afterglows of GRBs.
- To understand the origin and relationship of these flares to the prompt emission mechanism.
- To determine the most probable cause of observed X-ray flares in GRB afterglows.
Main Methods:
- Utilizing data from the Swift X-ray Telescope (XRT).
- Analyzing early X-ray afterglows of gamma-ray bursts (GRBs) with prompt follow-up observations.
- Characterizing flare properties such as fluence, rise time, and fall time.
Main Results:
- Flares were detected in approximately 50% of observed GRB afterglows.
- Flare fluences varied significantly, reaching up to 100% of the prompt GRB fluence.
- Flares exhibited rapid rise and fall times, shorter than the time elapsed since the burst.
Conclusions:
- The observed characteristics of flares suggest a connection to the prompt emission mechanism, possibly at lower photon energies.
- The most plausible explanation for these flares is continued, late-time activity from the gamma-ray burst central engine.
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