The discovery of a microarcsecond quasar: J1819+3845

Abstract

We report on the discovery of a source which exhibits over 300% amplitude changes in radio flux density on the period of hours. This source, J1819+3845, is the most extremely variable extragalactic source known in the radio sky. We believe these properties are due to interstellar scintillation, and show that the source must emit at least 55% of its flux density within a radius of <16 microarcseconds at 5GHz. The apparent brightness temperature is > 5.10^{12} K, and the source may be explained by a relativistically moving source with a Doppler factor ~15. The scattering occurs predominantly in material only a few tens of parsecs from the earth, which explains its unusually rapid variability. If the source PKS 0405-385 (Kedziora-Chudczer et al 1997) is similarly affected by local scattering material, Doppler factors of ~1000 are not required to explain this source. The discovery of a second source whose properties are well modeled by interstellar scintillation strengthens the argument for this as the cause for much of the variations seen in intra-day variables (IDV).

To appear in ApJL

Cited by in corpus (66)

• Blazars in the Fermi Era: The OVRO 40-m Telescope Monitoring Program
• The Dark Matter Distribution in Disk Galaxies
• Rapid Variability and Annual Cycles in the Characteristic Time-scale of the Scintillating Source PKS 1257-326
• Interstellar scintillation as the origin of rapid radio variability in the quasar J1819+3845
• First Results from MASIV: The Micro-Arcsecond Scintillation-Induced Variability Survey
• SubmilliJansky Transients in Archival Radio Observations
• Circular Polarization of Radio Emission from Relativistic Jets
• Interstellar Scintillation of the Polarized Flux Density in Quasar, PKS 0405-385
• Annual modulation in the scattering of J1819+3845: peculiar plasma velocity and anisotropy
• Annual modulation in IDV of quasar 0917+624 due to Interstellar Scintillation
• Rapid interstellar scintillation of PKS B1257-326: two-station pattern time delays and constraints on scattering and microarcsecond source structure
• Extrinsic Radio Variability of JVAS/CLASS Gravitational Lenses
• A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz
• Interstellar Scintillation Observations of 146 Extragalactic Radio Sources
• Cyclotron Maser Emission from Blazar Jets?
• The IDV source J1128+5925, a new candidate for annual modulation?
• Measuring the brightness temperature distribution of extragalactic radio sources with space VLBI
• Extreme radio-wave scattering associated with hot stars
• Intraday Variability in Northern Hemisphere Radio Sources
• Emergence and disappearance of micro-arcsecond structure in the scintillating quasar J1819+3845
• Variable 21cm absorption at z=0.3127
• Dynamic spectral mapping of interstellar plasma lenses
• On the radio afterglow of gamma ray bursts
• The Allen Telescope Array Pi GHz Sky Survey II. Daily and Monthly Monitoring for Transients and Variability in the Bootes Field
• Discovery of ASKAP J173608.2-321635 as a Highly-Polarized Transient Point Source with the Australian SKA Pathfinder
• Diffractive Interstellar Scintillation of the Quasar J1819+3845 at 21cm
• Intra-day variability observations of S5 0716+714 over 4.5 years at 4.8 GHz
• Green Bank Telescope observations of the water masers of NGC 3079: accretion disk magnetic field and maser scintillation
• The intra-hour variable quasar J1819$+$3845: 13-year evolution, jet polarization structure and interstellar scattering screen properties
• Electric field representation of pulsar intensity spectra
• Microarcsecond Radio Imaging using Earth Orbit Synthesis
• Annual Modulation in the Variability Properties of the IDV-Source 0917+624 ?
• A seasonal cycle and an abrupt change in the variability characteristics of the intraday variable source S4 0954+65
• Extremely Anisotropic Scintillations
• ASKAP observations of multiple rapid scintillators reveal a degrees-long plasma filament
• Power-law models of totally anisotropic scattering
• The MASIV Survey IV: relationship between intra-day scintillation and intrinsic variability of radio AGNs
• The Microarcsecond Sky and Cosmic Turbulence
• Detection of Six Rapidly Scintillating AGNs and the Diminished Variability of J1819+3845
• Pulsar Scintillation in the Local ISM: Loop I and Beyond
• A snowflake's chance in heaven
• Two-year monitoring of intra-day variability of quasar 1156+295 at 4.8 GHz
• Scintillation in the Circinus Galaxy water megamasers
• Scintillation as a Probe of the Intergalactic Medium
• Spica and the annual cycle of PKS B1322-110 scintillations
• The presence of interstellar scintillation in the 15 GHz interday variability of 1158 OVRO-monitored blazars
• Effelsberg Monitoring of a Sample of RadioAstron Blazars: Analysis of Intra-Day Variability
• Intra-day variability observations and the VLBI structure analysis of quasar S4 0917+624
• Intrinsic intraday variability in the gravitational lens system B0218+357
• Interstellar scintillation is an indicator of astrometric stability
• Rapid variability of BL Lac 0925+504: interstellar scintillation induced?
• On the influence of the Sun on the rapid variability of compact extragalactic sources
• Interstellar Scintillation of an Extreme Scintillator: PKS B1144-379
• The brightness temperature problem in extreme IDV quasars: a model for PKS 0405-385
• BL LAC PKSB1144-379 an extreme scintillator
• Radio observations of the first three-month Fermi-AGN at 4.8 GHz
• Scintillation-induced Variability in Radio Absorption Spectra against Extragalactic Sources
• Observations of Intrahour Variable Quasars: Scattering in our Galactic Neighbourhood
• Scintillation kinks, bumps and wiggles in the radio spectrum of the quasar PMN J1106-3647
• The Asymmetry Coefficient for Interstellar Scintillation of Extragalactic Radio Sources
• Milliarcsecond-Scale Structure in the Gamma-Ray Loud Quasar PKS 1622-297
• High frequency VLBI observations of the scatter broadened quasar B2005+403
• Observations of IntraDay Variable sources with the Effelsberg and Urumqi Radio Telescopes
• Optical study of PKS B1322-110, the intra-hour variable radio source
• Tidal disruption of "snow clouds" by unassociated stars
• The Unique Potential of SKA Radio Observations of Gamma-Ray Bursts