0000000000585403

AUTHOR

Gabriele Bruni

0000-0002-5182-6289

showing 4 related works from this author

Imaging strong blazars with space VLBI

2020

Abstract The RadioAstron mission has obtained a series of detailed multi-frequency images of the brightest blazars of the radio sky concentrated in three key science programs. We present here results of the program on powerful jets in blazars. In the first two years of the mission, observations of compact relativistic jets in 0836+710, 3C 345, 3C 273, and 4C +69.21 were made at λ λ  18, 6, and 1.3 cm. The resulting images have revealed compact emitting regions with brightness temperature in excess of 10 13  K and a complex jet structure that can be explained by plasma instability developing in a relativistic outflow. We present here some highlights of these space-VLBI observations, designed…

PhysicsAtmospheric ScienceJet (fluid)Active galactic nucleus010504 meteorology & atmospheric sciencesmedia_common.quotation_subjectAerospace EngineeringAstronomy and AstrophysicsAstrophysicsSpace (mathematics)01 natural sciencesGeophysicsAstrophysical jetSpace and Planetary ScienceSkyBrightness temperature0103 physical sciencesVery-long-baseline interferometryGeneral Earth and Planetary SciencesBlazar010303 astronomy & astrophysics0105 earth and related environmental sciencesmedia_commonAdvances in Space Research
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RadioAstron reveals a spine-sheath jet structure in 3C 273

2021

We present Space-VLBI RadioAstron observations at 1.6 GHz and 4.8 GHz of the flat spectrum radio quasar 3C 273, with detections on baselines up to 4.5 and 3.3 Earth Diameters, respectively. Achieving the best angular resolution at 1.6 GHz to date, we have imaged limb-brightening in the jet, not previously detected in this source. In contrast, at 4.8 GHz, we detected emission from a central stream of plasma, with a spatial distribution complementary to the limb-brightened emission, indicating an origin in the spine of the jet. While a stratification across the jet width in the flow density, internal energy, magnetic field, or bulk flow velocity are usually invoked to explain the limb-brighte…

Astrophysics::High Energy Astrophysical PhenomenaStratification (water)FOS: Physical sciencesJets [Galaxies]AstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciencesQuasars: individual: 3C 2730103 physical sciencesAngular resolution010303 astronomy & astrophysicsAstrophysics::Galaxy AstrophysicsPhysicsJet (fluid)Internal energy010308 nuclear & particles physicsAstronomy and AstrophysicsQuasarPlasmaGalaxies: activeAstrophysics - Astrophysics of GalaxiesActive [Galaxies]Magnetic fieldFlow velocitySpace and Planetary ScienceGalaxies: jetsAstrophysics of Galaxies (astro-ph.GA)Astrophysics::Earth and Planetary AstrophysicsIndividual: 3C 273 [Quasars]
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Multiband RadioAstron space VLBI imaging of the jet in quasar S5 0836+710

2019

Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.-- Open Access funding provided by Max Planck Society.

BrightnessActive galactic nucleusactive [Galaxies]010504 meteorology & atmospheric sciencesAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesContext (language use)galaxies [Radio continuum]AstrophysicsAstrophysics::Cosmology and Extragalactic Astrophysics01 natural sciences7. Clean energyGalaxies: individual: S5 0836+710Radio continuum: galaxiesRadio telescopeAstrophysical jet0103 physical sciencesVery-long-baseline interferometry010303 astronomy & astrophysics0105 earth and related environmental sciencesPhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)Jet (fluid)Computer Science::Information RetrievalAstronomy and AstrophysicsQuasarGalaxies: activeAstrophysics - Astrophysics of Galaxiesindividual: S5 0836+710 [Galaxies]Space and Planetary ScienceGalaxies: jetsAstrophysics of Galaxies (astro-ph.GA)jets [Galaxies]Astrophysics - High Energy Astrophysical Phenomena
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Probing the innermost regions of AGN jets and their magnetic fields with RadioAstron II. Observations of 3C 273 at minimum activity

2017

RadioAstron is a 10 m orbiting radio telescope mounted on the Spektr-R satellite, launched in 2011, performing Space Very Long Baseline Interferometry (SVLBI) observations supported by a global ground array of radio telescopes. With an apogee of about 350 000 km, it is offering for the first time the possibility to perform {\mu}as-resolution imaging in the cm-band. We present observations at 22 GHz of 3C 273, performed in 2014, designed to reach a maximum baseline of approximately nine Earth diameters. Reaching an angular resolution of 0.3 mas, we study a particularly low-activity state of the source, and estimate the nuclear region brightness temperature, comparing with the extreme one det…

PhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)BrightnessActive galactic nucleus010504 meteorology & atmospheric sciencesAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesAstronomy and AstrophysicsContext (language use)AstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysics - Astrophysics of Galaxies01 natural sciencesRadio telescopeSpace and Planetary ScienceBrightness temperatureAstrophysics of Galaxies (astro-ph.GA)0103 physical sciencesVery-long-baseline interferometryAstrophysics - High Energy Astrophysical PhenomenaBlazar010303 astronomy & astrophysicsAstrophysics::Galaxy Astrophysics0105 earth and related environmental sciencesFermi Gamma-ray Space Telescope
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