Radio-interferometric monitoring of FRB 131104: A coincident AGN flare, but no evidence for a cosmic fireball

Abstract

The localization of fast radio bursts (FRBs) has been hindered by the poor angular resolution of the detection observations and inconclusive identification of transient or variable counterparts. Recently a $\gamma$-ray pulse of $380$ s duration has been associated with the fast radio burst FRB 131104. We report on radio-continuum imaging observations of the original localization region of the FRB, beginning three days after the event and comprising 25 epochs over 2.5 yr. Besides probabilistic arguments that suggest that the association between the $\gamma$-ray transient and the FRB is not compelling, we provide upper limits on a putative radio afterglow of this transient that are at odds with standard models for its progenitor. We further report the discovery of an unusual variable radio source spatially and temporally coincident with FRB 131104, but not spatially coincident with the $\gamma$-ray event. The radio variable flares by a factor of $3$ above its long term average within $10$ d of the FRB at 7.5 GHz, with a factor-of-$2$ increase at $5.5$ GHz. Within our observations, the variable has persisted with only modest modulation and never approached the flux density observed in the days after the FRB. We identify an optical counterpart to the variable. Optical and infrared photometry, and deep optical spectroscopy, suggest that the object is a narrow-line radio AGN.

arXiv comment8 pages, 3 Figures, submitted to ApJ Letters

References in corpus (44)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The USNO-B Catalog
• A bright millisecond radio burst of extragalactic origin
• The Burst Alert Telescope (BAT) on the Swift MIDEX Mission
• Optical and Long Wavelength Afterglow from Gamma-Ray Bursts
• A New Electron Density Model for Estimation of Pulsar and FRB Distances
• A Population of Fast Radio Bursts at Cosmological Distances
• A Repeating Fast Radio Burst
• Spectral Energy Distributions of Hard X-ray selected AGNs in the XMDS Survey
• The direct localization of a fast radio burst and its host
• Mid-Infrared Selection of AGN with the Wide-Field Infrared Survey Explorer. I. Characterizing WISE-Selected AGN in COSMOS
• The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102
• Gamma-Ray Bursts in the Swift Era
• A model for fast extragalactic radio bursts
• The Repeating Fast Radio Burst FRB 121102 as Seen on Milliarcsecond Angular Scales
• Dense magnetized plasma associated with a fast radio burst
• Refreshed Shocks and Afterglow Longevity in GRB
• The Australia Telescope Compact Array Broadband Backend (CABB)
• Supergiant Pulses from Extragalactic Neutron Stars
• A Fast Radio Burst Host Galaxy
• A 450-day light curve of the radio afterglow of GRB 970508: Fireball calorimetry
• A Burst in a Wind Bubble and the Impact on Baryonic Ejecta: High-Energy Gamma-Ray Flashes and Afterglows from Fast Radio Bursts and Pulsar-Driven Supernova Remnants
• The magnetic field and turbulence of the cosmic web measured using a brilliant fast radio burst
• Fast Radio Bursts from the Inspiral of Double Neutron Stars
• How Soft Gamma Repeaters May Make Fast Radio Bursts
• Fast radio bursts: search sensitivities and completeness
• A fast radio burst in the direction of the Carina dwarf spheroidal galaxy
• The Caltech-NRAO Stripe 82 Survey (CNSS) Paper I: The Pilot Radio Transient Survey In 50 deg${}^2$
• No precise localization for FRB 150418: claimed radio transient is AGN variability
• Long-term radio variability of AGN: flare characteristics
• A VLA search for 5 GHz radio transients and variables at low Galactic latitudes
• Discovery of a transient gamma-ray counterpart to FRB 131104
• Interstellar Scintillation and the Radio Counterpart of the Fast Radio Burst FRB150418
• Real-time detection of an extreme scattering event: constraints on Galactic plasma lenses
• Induced scattering of short radio pulses
• A mechanism for fast radio bursts
• The Fluence and Distance Distributions of Fast Radio Bursts
• Radio Broadcasts from Superconducting Strings
• On associating Fast Radio Bursts with afterglows
• Fast Radio Bursts with Extended Gamma-Ray Emission?
• A search for variable and transient radio sources in the extended Chandra Deep Field South at 5.5 GHz
• The Rest-frame Optical Colors of 99,000 SDSS Galaxies
• Radio light curve of the galaxy possibly associated with FRB150418

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• Fast Radio Bursts
• A Living Theory Catalogue for Fast Radio Bursts
• INTEGRAL discovery of a burst with associated radio emission from the magnetar SGR 1935+2154
• The SUrvey for Pulsars and Extragalactic Radio Bursts II: New FRB discoveries and their follow-up
• Simultaneous X-ray, gamma-ray, and Radio Observations of the repeating Fast Radio Burst FRB 121102
• Multiwavelength observations of Fast Radio Bursts
• Deep optical observations contemporaneous with emission from the periodic FRB 180916.J0158+65
• Zwicky Transient Facility constraints on the optical emission from the nearby repeating FRB 180916.J0158+65
• Collapsing supra-massive magnetars: FRBs, the repeating FRB121102 and GRBs
• A cumulative search for hard X/$\gamma$-Ray emission associated with fast radio bursts in Fermi/GBM data
• Associating Fast Radio Bursts with Extragalactic Radio Sources: General Methodology and a Search for a Counterpart to FRB 170107
• Search for GeV counterparts to fast radio bursts with Fermi
• A search for gamma-ray prompt emission associated with the Lorimer Burst FRB010724
• FRB131104 Swift BAT data revisited: No evidence of a gamma-ray counterpart
• Detectability of radio afterglows from binary neutron star mergers and implications for fast radio bursts
• Constraining the Environmental Properties of FRB 131104 Using the Unified Dynamical Afterglow Model