A Reverse Shock in GRB 181201A

Abstract

We present comprehensive multiwavelength radio to X-ray observations of GRB 181201A spanning from $\approx 150$ s to $\approx 163$ days after the burst, comprising the first joint ALMA-VLA-GMRT observations of a gamma-ray burst (GRB) afterglow. The radio and mm-band data reveal a distinct signature at $\approx 3.9$ days, which we interpret as reverse shock (RS) emission. Our observations present the first time that a single radio-frequency spectral energy distribution can be decomposed directly into RS and forward shock (FS) components. We perform detailed modeling of the full multiwavelength data set, using Markov Chain Monte Carlo sampling to construct the joint posterior density function of the underlying physical parameters describing the RS and FS synchrotron emission. We uncover and account for all degeneracies in the model parameters. The joint RS-FS modeling reveals a weakly magnetized ($\sigma \approx 3\times 10^{-3}$), mildly relativistic RS, from which we derive an initial bulk Lorentz factor of ${\Gamma }_0\approx 103$ for the GRB jet. Our results support the hypothesis that low-density environments are conducive to the observability of RS emission. We compare our observations to other events with strong RS detections, and find a likely observational bias selecting for longer lasting, non-relativistic reverse shocks. We present and begin to address new challenges in modeling posed by the present generation of comprehensive, multi-frequency data sets.

Accepted version

References in corpus (87)

• emcee: The MCMC Hammer
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Swift X-ray Telescope
• Spectra and Light Curves of Gamma-Ray Burst Afterglows
• The Swift Ultra-Violet/Optical Telescope
• The Supernova -- Gamma-Ray Burst Connection
• Unsteady Outflow Models for Cosmological Gamma-Ray Bursts
• Gamma-Ray Bursts
• Jets in GRBs
• Photometric Calibration of the Swift Ultraviolet/Optical Telescope
• Evidence for a Canonical GRB Afterglow Light Curve in the Swift/XRT Data
• The Dynamics and Light Curves of Beamed Gamma Ray Burst Afterglows
• The Shape of Spectral Breaks in GRB Afterglows
• The Proto-Magnetar Model for Gamma-Ray Bursts
• Observation of contemporaneous optical radiation from a gamma-ray burst
• Wind Interaction Models for Gamma-Ray Burst Afterglows: The Case for Two Types of Progenitors
• Predictions for The Very Early Afterglow and The Optical Flash
• On The Synchrotron Self-Compton Emission from Relativistic Shocks and Its Implications for Gamma-Ray Burst Afterglows
• The Ep,i - Eiso correlation in GRBs: updated observational status, re-analysis and main implications
• Analytic Light-Curves of Gamma-Ray Burst Afterglows: Homogeneous versus Wind External Media
• Poynting Jets from Black Holes and Cosmological Gamma-Ray Bursts
• GRB990123, The Optical Flash and The Fireball Model
• Massive Stars in the Quintuplet Cluster
• A Common Origin for Cosmic Explosions Inferred from Fireball Calorimetry
• Light Curves of GRB Optical Flashes
• Gamma-ray burst early optical afterglows: implications for the initial Lorentz factor and the central engine
• GRB Radiative Efficiencies Derived from the Swift Data: GRBs vs. XRFs, Long vs. Short
• GRB 990123: Reverse and Internal Shock Flashes and Late Afterglow
• Impulsive and Varying Injection in GRB Afterglows
• A 450-day light curve of the radio afterglow of GRB 970508: Fireball calorimetry
• Gamma-ray burst early afterglows: reverse shock emission from an arbitrarily magnetized ejecta
• REM observations of GRB 060418 and GRB 060607A: the onset of the afterglow and the initial fireball Lorentz factor determination
• Constraining GRB Initial Lorentz Factor with the Afterglow Onset Feature and Discovery of a Tight Gamma_0-E_iso Correlation
• The 2175 A dust feature in a Gamma Ray Burst afterglow at redshift 2.45
• Klein-Nishina Effects on Optically Thin Synchrotron and Synchrotron Self-Compton Spectrum
• The Afterglow of GRB 130427A from 1 to 10^16 GHz
• Master Robotic Net
• A Comprehensive Analysis of Swift/XRT Data: III. Jet Break Candidates in X-ray and Optical Afterglow Lightcurves
• Radio-to-FIR Spectral Energy Distribution and Photometric Redshifts for Dusty Starburst Galaxies
• Implications of the radio afterglow from the gamma-ray burst of May 8, 1997
• Short GRB 130603B: Discovery of a jet break in the optical and radio afterglows, and a mysterious late-time X-ray excess
• Hydrodynamics of a Relativistic Fireball: the Complete Evolution
• A Standard Kinetic Energy Reservoir in Gamma-Ray Burst Afterglows
• Linear Polarization in Gamma-Ray Bursts: The Case for an Ordered Magnetic Field
• Optical Flashes and Radio Flares in GRBs afterglow: Numerical Study
• A Submillimeter and Radio Survey of Gamma-Ray Burst Host Galaxies: A Glimpse into the Future of Star Formation Studies
• Energies of GRB blast waves and prompt efficiencies as implied by modeling of X-ray and GeV afterglows
• The efficiency of electron acceleration in collisionless shocks and GRB energetics
• A Reverse Shock in GRB 130427A
• Discovery of a Radio Flare from GRB 990123
• Early Afterglow Emission from a Reverse Shock as a Diagnostic Tool for GRB Outflows
• On the Kinetic Energy and Radiative Efficiency of Gamma-Ray Bursts
• Simulations of GRB Jets in a Stratified External Medium: Dynamics, Afterglow Lightcurves, Jet Breaks and Radio Calorimetry
• A comprehensive study of GRB 070125, a most energetic gamma ray burst
• Multiwavelength analysis of the intriguing GRB 061126: the reverse shock scenario and magnetization
• The Onset of Gamma-Ray Burst Afterglow
• Energy Injection in Gamma-ray Burst Afterglows
• Accurate Calorimetry of GRB 030329
• A Comprehensive Radio View of the Extremely Bright Gamma-Ray Burst 130427A
• GRB 120521C at z~6 and the Properties of High-redshift GRBs
• Early Afterglows in Wind Environments Revisited
• Behavior of X-Ray Dust Scattering and Implications for X-Ray Afterglows of Gamma-Ray Bursts
• A Reverse Shock in GRB 160509A
• Phenomenology of Reverse-Shock Emission in the Optical Afterglows of Gamma Ray Bursts
• GRB 090313 and the Origin of Optical Peaks in GRB Light Curves: Implications for Lorentz Factors and Radio Flares
• ALMA Detection of a Linearly Polarized Reverse Shock in GRB 190114C
• Radio Flares and the Magnetic Field Structure in GRB Outflows
• The Non-Relativistic Evolution of GRBs 980703 and 970508: Beaming-Independent Calorimetry
• A Reverse Shock and Unusual Radio Properties in GRB 160625B
• First ALMA Light Curve Constrains Refreshed Reverse Shocks and Jet Magnetization in GRB 161219B
• Thermal Electrons in GRB Afterglows
• Dust in the wind: the role of recent mass loss in long gamma-ray bursts
• The Two-Component Afterglow of Swift GRB 050802
• Reverse Shock Emission as a Probe of GRB Ejecta
• The Slow Decay of Some Radio Afterglows, a Puzzle for the Simplest GRB Fireball Model
• A VLA Study of High-redshift GRBs II - The Complex Radio Afterglow of GRB 140304A: Shell Collisions and Two Reverse Shocks
• No flares from Gamma-Ray Burst afterglow blast waves encountering sudden circumburst density change
• A VLA Study of High-redshift GRBs I - Multi-wavelength Observations and Modeling of GRB 140311A
• A Beaming-Independent Estimate of the Energy Distribution of Long Gamma-Ray Bursts: Initial Results and Future Prospects
• GRB afterglow light curves from realistic density profiles
• Late-Time VLA Reobservations Rule Out ULIRG-Like Host Galaxies For Most Pre-Swift Long-Duration Gamma-Ray Bursts
• Pair-dominated GeV-optical flash in GRB 130427A
• Radio rebrightening of the GRB afterglow by the accompanying supernova
• Late-Time Radio Re-Brightening of Gamma-Ray Burst Afterglows: Evidence for Double-Sided Jets
• GRB 081029: A Gamma-Ray Burst with a Multi-Component Afterglow
• GRB off-axis afterglows and the emission from the accompanying supernovae
• Early GRB afterglows from reverse shocks in ultra-relativistic long-lasting winds

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