Minimum Energies and Magnetic Field Strengths of Edge-brightened Compact Symmetric Objects

Abstract

Compact symmetric objects (CSOs) are subkiloparsec radio sources with two-sided emission about a core resulting from jets that are not relativistically beamed towards the observer. This relative simplicity makes them attractive targets to study the launching and evolution of relativistic jets. We use radio surveys and spatially resolved VLBA observations to estimate the minimum energies and magnetic field strengths of a subset of edge-brightened CSOs (CSO-2s). These are necessary to test models of CSO-2 formation via stellar capture and evolution via synchrotron cooling. By treating the observed X-ray emission of CSO-2s as inverse Compton emission from synchrotron and external photon fields, we estimate a mean departure from the minimum energy magnetic field strengths of $\sim 2\times$, suggesting that CSO-2 lobes are close to minimum energy. Typical lobal minimum energy magnetic field strengths of $20$ mG suggest that once the jets shut off, luminous CSO-2s should fade at GHz frequencies within $\sim 10^3$ years. We find that CSO-2 minimum energies are systematically larger than previously estimated. If luminous CSO-2s result from tidal disruption events, a majority would require the capture of massive stars $>1M_{\odot }$ assuming jet launching efficiencies less than $100\%$.

Published to ApJ

References in corpus (21)

• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• The UKIRT Infrared Deep Sky Survey (UKIDSS)
• The LOFAR Two-metre Sky Survey - I. Survey Description and Preliminary Data Release
• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• The LOFAR Two-metre Sky Survey -- V. Second data release
• CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources
• Revised equipartition & minimum energy formula for magnetic field strength estimates from radio synchrotron observations
• MOJAVE: XV. VLBA 15 GHz Total Intensity and Polarization Maps of 437 Parsec-Scale AGN Jets From 1996-2017
• Imfit: A Fast, Flexible New Program for Astronomical Image Fitting
• A Quick Look at the $3$GHz Radio Sky I. Source Statistics from the Very Large Array Sky Survey
• The Rapid ASKAP Continuum Survey Paper II: First Stokes I Source Catalogue Data Release
• On the Evolution of and High-Energy Emission from GHz-Peaked-Spectrum Sources
• Are young radio sources in equipartition?
• VLSS Redux: Software Improvements applied to the Very Large Array Low-frequency Sky Survey
• The Radio Fundamental Catalogue. I. Astrometry
• The LOFAR LBA Sky Survey II. First data release
• ALMA photometry of extragalactic radio sources
• The inverse-Compton X-ray-emitting lobes of the high-redshift giant radio galaxy 6C 0905+39
• The Relativistic Jet Orientation and Host Galaxy of the Peculiar Blazar PKS 1413+135
• VLBA 24 and 43 GHz observations of massive binary black hole candidate PKS 1155+251
• AGN feedback in an infant galaxy cluster: the LOFAR-Chandra view of the giant FRII radio galaxy J103025+052430 at z=1.7