RadioSED I: Bayesian inference of radio SEDs from inhomogeneous surveys

Abstract

We present here RadioSED, a Bayesian inference framework tailored to modelling and classifying broadband radio spectral energy distributions (SEDs) using only data from publicly-released, large-area surveys. We outline the functionality of RadioSED, with its focus on broadband radio emissions which can trace kiloparsec-scale absorption within both the radio jets and the circumgalactic medium of Active Galactic Nuclei (AGN). In particular, we discuss the capability of RadioSED to advance our understanding of AGN physics and composition within youngest and most compact sources, for which high resolution imaging is often unavailable. These young radio AGN typically manifest as peaked spectrum (PS) sources which, before RadioSED, were difficult to identify owing to the large, broadband frequency coverage typically required, and yet they provide an invaluable environment for understanding AGN evolution and feedback. We discuss the implementation details of RadioSED, and we validate our approach against both synthetic and observational data. Since the surveys used are drawn from multiple epochs of observation, we also consider the output from RadioSED in the context of AGN variability. Finally, we show that RadioSED recovers the expected SED shapes for a selection of well-characterised radio sources from the literature, and we discuss avenues for further study of these and other sources using radio SED fitting as a starting point. The scalability and modularity of this framework make it an exciting tool for multiwavelength astronomers as next-generation telescopes begin several all-sky surveys. Accordingly, we make the code for RadioSED, which is written in Python, available on Github.

20 pages, 2 tables, 15 figures. Accepted for publication in MNRAS

References in corpus (43)

• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• A simple model to interpret the ultraviolet, optical and infrared emission from galaxies
• astroquery: An Astronomical Web-Querying Package in Python
• 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
• CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources
• The VLA Low-frequency Sky Survey
• Distant Radio Galaxies and their Environments
• Roma-BZCAT: A multifrequency catalogue of Blazars
• Radio sources in the 6dFGS: Local luminosity functions at 1.4 GHz for star-forming galaxies and radio-loud AGN
• The 5th edition of the Roma-BZCAT. A short presentation
• The Last of FIRST: The Final Catalog and Source Identifications
• The Rapid ASKAP Continuum Survey I: Design and First Results
• CGRaBS: An All-Sky Survey of Gamma-Ray Blazar Candidates
• The Very Large Array Low-frequency Sky Survey Redux (VLSSr)
• A Quick Look at the $3$GHz Radio Sky I. Source Statistics from the Very Large Array Sky Survey
• Fitting AGN/galaxy X-ray-to-radio SEDs with CIGALE and improvement of the code
• The Rapid ASKAP Continuum Survey Paper II: First Stokes I Source Catalogue Data Release
• The Art of Measuring Physical Parameters in Galaxies: A Critical Assessment of Spectral Energy Distribution Fitting Techniques
• Extragalactic Peaked-Spectrum Radio Sources at Low Frequencies
• A Unified Catalog of Radio Objects Detected by NVSS, FIRST, WENSS, GB6, and SDSS
• Statistical analyses of long-term variability of AGN at high radio frequencies
• The Energetics and Lifetimes of Local Radio Active Galactic Nuclei
• Quasars That Have Transitioned from Radio-quiet to Radio-loud on Decadal Timescales Revealed by VLASS and FIRST
• Radio galaxies in the 2SLAQ Luminous Red Galaxy Survey: I. The evolution of low-power radio galaxies to z~0.7
• Long-term radio variability of AGN: flare characteristics
• Two new catalogs of blazar candidates in the WISE infrared sky
• The curvature of spectral energy distribution of blazars
• Constraining the nature of High Frequency Peakers. I. The spectral variability
• The Rapid ASKAP Continuum Survey IV: continuum imaging at 1367.5 MHz and the first data release of RACS-mid
• The Large Area Radio Galaxy Evolution Spectroscopic Survey (LARGESS): Survey design, data catalogue and GAMA/WiggleZ spectroscopy
• ALMA photometry of extragalactic radio sources
• Spectral Variability of Radio Sources at Low Frequencies
• Caltech-NRAO Stripe 82 Survey (CNSS) Paper V: AGNs that transitioned to radio-loud state
• A southern-sky total intensity source catalogue at 2.3 GHz from S-band Polarisation All-Sky Survey data
• RAiSE: simulation-based analytical model of AGN jets and lobes
• The MASIV Survey IV: relationship between intra-day scintillation and intrinsic variability of radio AGNs
• Observations by GMRT at 323 MHz of radio-loud quasars at $z>5$
• Galactic and Extragalactic Sources of Very High Energy Gamma-rays
• The C-Band All-Sky Survey: Instrument design, status, and first-look data
• FLASH Pilot Survey: Detections of associated 21 cm HI absorption in GAMA galaxies at 0.42 < z <1.00
• First measurement of interplanetary scintillation with the ASKAP radio telescope: implications for space weather
• A census of compact sources at 162MHz: first data release from the MWA Phase II IPS Survey

Cited by in corpus (1)

• A FLASH on Blazars: Capturing the Radio Realm of 4FGL Blazars with SKAO Pathfinders