Early Optical Polarization of a Gamma Ray Burst Afterglow

Abstract

We report the optical polarization of a gamma ray burst (GRB) afterglow, obtained 203 seconds after the initial burst of gamma rays from GRB 060418, using a ring polarimeter on the robotic Liverpool Telescope. Our robust (2-sigma) upper limit on the percentage of polarization, less than 8%, coincides with the fireball deceleration time at the onset of the afterglow. The combination of the rate of decay of the optical brightness and the low polarization at this critical time constrains standard models of GRB ejecta, ruling out the presence of a large-scale ordered magnetic field in the emitting region.

arXiv comment8 pages including 1 figure. Accepted for publication in Science; published online 15 March 2007; 10.1126/science.1138484

References in corpus (27)

• Spectra and Light Curves of Gamma-Ray Burst Afterglows
• The Physics of Gamma-Ray Bursts
• Gamma-Ray Bursts
• Beaming in Gamma-Ray Bursts: Evidence for a Standard Energy Reservoir
• Physical processes shaping GRB X-ray afterglow lightcurves: theoretical implications from the Swift XRT observations
• Evidence for a Canonical GRB Afterglow Light Curve in the Swift/XRT Data
• Efficient acceleration and radiation in Poynting flux powered GRB outflows
• Polarization of the prompt gamma-ray emission from the gamma-ray burst of 6 December 2002
• Gamma-Ray Burst Afterglow: Polarization and Analytic Light Curves
• Polarization of prompt GRB emission: evidence for electromagnetically-dominated outflow
• Hydrodynamics of a Relativistic Fireball: the Complete Evolution
• Linear Polarization in Gamma-Ray Bursts: The Case for an Ordered Magnetic Field
• Gravitational Lens Time Delays: A Statistical Assessment of Lens Model Dependences and Implications for the Global Hubble Constant
• The polarisation of afterglow emission reveals GRB jet structure
• Re-Analysis of Polarization in the Gamma-ray flux of GRB 021206
• GRB 021004: Reverse Shock Emission
• The electromagnetic model of Gamma Ray Bursts
• Evolution of the polarization of the optical afterglow of the gamma-ray burst GRB 030329
• Optical Spectropolarimetry of the GRB 020813 Afterglow
• Evidence of polarisation in the prompt gamma-ray emission from GRB 930131 and GRB 960924
• The Strongly Polarized Afterglow of GRB 020405
• Radio Flares and the Magnetic Field Structure in GRB Outflows
• Flat FRW Cosmologies with Adiabatic Matter Creation: Kinematic tests
• Magnetic Fields in Gamma-Ray Bursts: A Short Review
• On the jet structure and magnetic field configuration of GRB 020813
• Probing the Magnetic Field Structure in Gamma-Ray Bursts through Dispersive Plasma Effects on the Afterglow Polarization
• Polarimetric observations of GRB 011211

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• Detailed optical and near-infrared polarimetry, spectroscopy and broadband photometry of the afterglow of GRB 091018: Polarisation evolution
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• Spectral catalogue of bright gamma-ray bursts detected with the BeppoSAX/GRBM
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• Distributions of Gamma-Ray Bursts and Blazars in the $L_{\mathrm{p}}-E_{\mathrm{p}}$ Plane and Possible Implications for their Radiation Physics
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• Linear Polarization, Circular Polarization, and Depolarization of Gamma-ray Bursts: A Simple Case of Jitter Radiation
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• A robotic pipeline for fast GRB followup with the Las Cumbres observatory network
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