A Flat-Spectrum Radio Transient at 122 Mpc consistent with an Emerging Pulsar Wind Nebula

Abstract

We report the discovery and follow-up observations of VT 1137-0337: an unusual radio transient found in our systematic search for extragalactic explosions in the VLA Sky Survey (VLASS). VT 1137-0337 is located in the brightest region of a dwarf starburst galaxy (stellar mass $\sim 10^{8.3}{M}_{\odot }$, star formation rate $\sim 0.5M_{\odot }$ yr${}^{-1}$) at a luminosity distance of 121.6 Mpc. Its 3 GHz luminosity of $\sim 2.5\times 10^{28}$ erg s${}^{-1}$ Hz${}^{-1}$ is comparable to luminous radio supernovae associated with dense circumstellar interaction and relativistic outflows. However, its broadband radio spectrum - a featureless power law $\propto {\nu }^{-0.35\pm 0.02}$ over a range of $\gtrsim$10$\times$ in frequency and fading at a rate of $\sim$ 5% per year over 4 years - cannot be directly explained by the shock of a stellar explosion. Jets launched by various classes of accreting black holes also struggle to account for VT 1137-0337's combination of observational properties. Instead, we propose that VT 1137-0337 is a $\sim$decades old pulsar wind nebula that has recently emerged from within the free-free opacity of its surrounding supernova ejecta. If the nebula is powered by spindown, the central neutron star should be highly magnetized, with a surface dipole field of $\sim 10^{13}-10^{14}$ G and a present-day spin period of $\sim 10-100$ ms. Alternatively, the nebula may be powered by the release of magnetic energy from a magnetar. Magnetar nebulae have been proposed to explain the persistent radio sources associated with the repeating fast radio bursts FRB 121102 and FRB 190520B. These FRB persistent sources have not previously been observed as transients, but do bear a striking resemblance to VT 1137-0337 in their radio luminosity, spectral index, and host galaxy properties.

arXiv commentUpdated to version accepted by ApJ (minor updates to text & fig. 9)

References in corpus (147)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• The NumPy array: a structure for efficient numerical computation
• The chemical composition of the Sun
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• Unified Schemes for Radio-Loud Active Galactic Nuclei
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The ATNF Pulsar Catalogue
• Star Formation in the Milky Way and Nearby Galaxies
• Theoretical Modeling of Starburst Galaxies
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• Secular Evolution and the Formation of Pseudobulges in Disk Galaxies
• Metallicity Calibrations and the Mass-Metallicity Relation for Star-Forming Galaxies
• Towards a unified model for black hole X-ray binary jets
• A Cosmology Calculator for the World Wide Web
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• Mass Loss: Its Effect on the Evolution and Fate of High-Mass Stars
• Magnetars
• Calibrating Extinction-Free Star Formation Rate Diagnostics with 33GHz Free-Free Emission in NGC6946
• The direct localization of a fast radio burst and its host
• Relations Between Central Black Hole Mass and Total Galaxy Stellar Mass in the Local Universe
• The Evolution and Structure of Pulsar Wind Nebulae
• Supernova Light Curves Powered by Young Magnetars
• A fast radio burst associated with a Galactic magnetar
• A bright millisecond-duration radio burst from a Galactic magnetar
• Intermediate-Mass Black Holes
• The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102
• The chemical composition of metal-poor emission-line galaxies in the Data Release 3 of the Sloan Digital Sky Survey
• The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release
• Dust Attenuation Curves in the Local Universe: Demographics and New Laws for Star-forming Galaxies and High-redshift Analogs
• Optical Spectroscopy and Nebular Oxygen Abundances of the Spitzer/SINGS Galaxies
• Relativistic ejecta from XRF 060218 and the rate of cosmic explosions
• The Expanded Very Large Array -- a New Telescope for New Science
• The First CHIME/FRB Fast Radio Burst Catalog
• A relationship between AGN jet power and radio power
• Theoretical Evolution of Optical Strong Lines across Cosmic Time
• The 1% Concordance Hubble Constant
• The Birth of a Relativistic Outflow in the Unusual γ-ray Transient Swift J164449.3+573451
• An Open Catalog for Supernova Data
• A mildly relativistic wide-angle outflow in the neutron star merger GW170817
• An Accurate Flux Density Scale from 50 MHz to 50 GHz
• Millisecond Magnetar Birth Connects FRB 121102 to Superluminous Supernovae and Long Duration Gamma-ray Bursts
• The Fifteenth Data Release of the Sloan Digital Sky Surveys: First Release of MaNGA Derived Quantities, Data Visualization Tools and Stellar Library
• The Third Swift Burst Alert Telescope Gamma-Ray Burst Catalog
• The Association of Jet Production with Geometrically Thick Accretion Flows and Black Hole Rotation
• A Relativistic Type Ibc Supernova Without a Detected Gamma-ray Burst
• The Structure of the M87 Jet: A Transition from Parabolic to Conical Streamlines
• A flaring magnetar in FRB 121102?
• A repeating fast radio burst source in a globular cluster
• A repeating fast radio burst associated with a persistent radio source
• Acceleration of Particles at the Termination Shock of a Relativistic Striped Wind
• Dust extinction from Balmer decrements of star-forming galaxies at 0.75<z<1.5 with HST/WFC3 spectroscopy from the WISP survey
• The extent of power-law energy spectra in collisionless relativistic magnetic reconnection in pair plasmas
• 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
• Magnetar-like Emission from the Young Pulsar in Kes 75
• A revised catalogue of 294 Galactic supernova remnants
• The ultraluminous state revisited: fractional variability and spectral shape as diagnostics of super-Eddington accretion
• A tidal disruption event coincident with a high-energy neutrino
• Fully-Automated Reduction of Longslit Spectroscopy with the Low Resolution Imaging Spectrometer at Keck Observatory
• The Most Luminous Supernovae
• Common Envelope Evolution Leading to Supernovae with Dense Interaction
• A New Sample of (Wandering) Massive Black Holes in Dwarf Galaxies from High Resolution Radio Observations
• Three-dimensional simulations of super-critical black hole accretion disks --- luminosities, photon trapping and variability
• Discovery of an outflow from radio observations of the tidal disruption event ASASSN-14li
• A concordance picture of FRB 121102 as a flaring magnetar embedded in a magnetized ion-electron wind nebula
• Carnegie Supernova Project: Observations of Type IIn supernovae
• On the diversity of super-luminous supernovae: ejected mass as the dominant factor
• Swift J1644+57 gone MAD: the case for dynamically-important magnetic flux threading the black hole in a jetted tidal disruption event
• The Carnegie Supernova Project I: analysis of stripped-envelope supernova light curves
• Early-time light curves of Type Ib/c supernovae from the SDSS-II Supernova Survey
• A dust-enshrouded tidal disruption event with a resolved radio jet in a galaxy merger
• FRB 121102 is coincident with a star forming region in its host galaxy
• Multimessenger Signatures of Massive Black Holes in Dwarf Galaxies
• AT2018cow: a luminous millimeter transient
• Magnetar heating
• CHIME/FRB Detection of the Original Repeating Fast Radio Burst Source FRB 121102
• Radio Supernova SN 1998bw and Its Relation to GRB 980425
• Formation Rates and Evolution Histories of Magnetars
• The Koala: A Fast Blue Optical Transient with Luminous Radio Emission from a Starburst Dwarf Galaxy at $z=0.27$
• The very flat radio - millimetre spectrum of Cygnus X-1
• Magnetar formation through a convective dynamo in protoneutron stars
• Theoretical ISM pressure and electron density diagnostics for local and high-redshift galaxies
• Significant core shift variability in parsec-scale jets of active galactic nuclei
• Radio Monitoring of the Tidal Disruption Event Swift J164449.3+573451. III. Late-time Jet Energetics and a Deviation from Equipartition
• A giant radio flare from Cygnus X-3 with associated Gamma-ray emission
• Quasars That Have Transitioned from Radio-quiet to Radio-loud on Decadal Timescales Revealed by VLASS and FIRST
• Spatial analysis of the Halpha emission in the local star-forming UCM galaxies
• The Core Collapse Supernova Rate from the SDSS-II Supernova Survey
• Radio Observations of an Ordinary Outflow from the Tidal Disruption Event AT2019dsg
• A Sample of Massive Black Holes in Dwarf Galaxies Detected via [Fe X] Coronal Line Emission: Active Galactic Nuclei and/or Tidal Disruption Events
• The variability timescales and brightness temperatures of radio flares from stars to supermassive black holes
• Limits on radio emission from pulsar wind nebulae
• Evolution of the Radio Remnant of SN 1987A: 1990 -- 2001
• The Radio Luminosity-Risetime Function of Core-Collapse Supernovae
• Type II supernovae from the Carnegie Supernova Project-I. II. Physical parameter distributions from hydrodynamical modelling
• Radio observations of the tidal disruption event XMMSL1 J0740$-$85
• Populations of stellar mass Black holes from binary systems
• Revealing the intermediate-mass black hole at the heart of the dwarf galaxy NGC 404 with sub-parsec resolution ALMA observations
• Global spectral energy distribution of the Crab Nebula in the prospect of the Planck satellite polarisation calibration
• Census of the Local Universe (CLU) Narrow-Band Survey I: Galaxy Catalogs from Preliminary Fields
• Core-collapse, superluminous, and gamma-ray burst supernova host galaxy populations at low redshift: the importance of dwarf and starbursting galaxies
• The Limitations of Optical Spectroscopic Diagnostics in Identifying AGNs in the Low Mass Regime
• The Crab Nebula's Moving Wisps in Radio
• Caltech-NRAO Stripe 82 Survey (CNSS). III: The First Radio-discovered Tidal Disruption Event, CNSS J0019+00
• Rotational evolution of the Crab pulsar in the wind braking model
• The 1st INTEGRAL SPI-ACS Gamma-Ray Burst Catalogue
• A composite HII region luminosity function in H alpha of unprecedented statistical weight
• The wind nebula around magnetar Swift J1834.9-0846
• Discovery of the Luminous, Decades-Long, Extragalactic Radio Transient FIRST J141918.9+394036
• Interpreting Crab Nebula synchrotron spectrum: two acceleration mechanisms
• Diffusive Synchrotron Radiation from Relativistic Shocks of Gamma-Ray Burst Sources
• Super-giant pulses from the Crab pulsar : Energy distribution and occurrence rate
• Lorentz Factors of compact jets in Black hole X-ray binaries
• Type II Supernova Light Curves and Spectra From the CfA
• A transient radio source consistent with a merger-triggered core collapse supernova
• Pulsar Wind Nebulae: Theoretical Aspects and Observational Constraints
• Towards understanding the physics of collisionless relativistic shocks
• On the Fast Radio Burst and Persistent Radio Source Populations
• Expansion and Brightness Changes in the Pulsar-Wind Nebula in the Composite Supernova Remnant Kes 75
• A Multi-wavelength Study of the Turbulent Central Engine of the Low-mass AGN hosted by NGC404
• Hard Synchrotron Spectra from Magnetically Dominated Plasma Turbulence
• Bimodal radio variability in OVRO-40m-monitored blazars
• The Star Formation in Radio Survey: 3 - 33 GHz Imaging of Nearby Galaxy Nuclei and Extranuclear Star-forming Regions
• On the Radio Emitting Particles of the Crab Nebula: Stochastic Acceleration Model
• Diffusive Synchrotron Radiation from Pulsar Wind Nebulae
• Multi-wavelength Observations of AT2019wey: a New Candidate Black Hole Low-mass X-ray Binary
• The double-peaked radio light curve of PTF11qcj
• MAXI observations of GRBs
• Outflows, Shocks and Coronal Line Emission in a Radio-Selected AGN in a Dwarf Galaxy
• A search for FRB 121102-like persistent radio-luminous sources -- Candidates and implications for the FRB rate and searches
• Interpreting the Ionization Sequence in Star-Forming Galaxy Emission-Line Spectra
• The Absolute Rate of LGRB Formation
• Relativistic Beaming and Flux Variability in Active Galactic Nuclei
• Physics of the saturation of particle acceleration in relativistic magnetic reconnection
• Implications of the lowest frequency detection of the persistent counterpart of FRB121102
• Compact Resolved Ejecta in the Nearest Tidal Disruption Event
• The Redshift Completeness of Local Galaxy Catalogs
• The nascent milliquasar VT J154843.06+220812.6: tidal disruption event or extreme accretion-state change?
• FIRST J153350.8+272729: the radio afterglow of a decades-old tidal disruption event
• The Caltech-NRAO Stripe 82 Survey (CNSS) Paper II: On-The-Fly Mosaicing Methodology
• Investigating the mini and giant radio flare episodes of Cygnus X-3
• GRB 030329: 3 years of radio afterglow monitoring
• Empirical Assessment of Aperiodic and Periodic Radio Bursts from Young Precessing Magnetars
• The ASKAP Variables and Slow Transients (VAST) Pilot Survey

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