Radio spectral index distribution of SDSS-FIRST sources across optical diagnostic diagrams

Abstract

A detailed understanding of how the activity of a galactic nucleus regulates the growth of its host is still missing. To understand the activity and the types of accretion of supermassive black holes in different hosts, it is essential to study radio-optical properties of a large sample of extragalactic sources. In particular, we aim at studying the radio spectral index trends across the optical emission line diagnostic diagrams to search for potential (anti)correlations. To this goal, we combine flux densities from the radio FIRST survey at $1.4\mathrm{GHz}$ (with the flux density range $10\mathrm{mJy}\le F_{1.4}\le 1000\mathrm{mJy}$) for 209 SDSS sources at intermediate redshift $(0.04\le z\le 0.4)$ with the Effelsberg radiotelescope measurements at $4.85\mathrm{GHz}$ and $10.45\mathrm{GHz}$. The information about the optical emission-line ratios is obtained from the SDSS-DR7 catalogue. Using the Effelsberg data, we were able to infer the two-point radio spectral index distributions for star-forming galaxies, composite galaxies (with a combined contribution to the line emission from the star-formation and AGN activity), Seyferts, and low ionization narrow emission region (LINER) galaxies. While studying the distribution of steep, flat, and inverted sources across optical diagnostic diagrams, we found three distinct classes of radio emitters for our sample: (i) sources with steep radio index, high ionization ratio and high radio loudness, (ii) sources with flat radio index, lower ionization ratio and intermediate radio loudness, (iii) sources with inverted radio index, low ionization ratio and low radio loudness. The classes (i), (ii), (iii) cluster mainly along the transition from Seyfert to LINER sources in the BPT diagram. We interpret these groups as a result of the recurrent nuclear-jet activity.

arXiv comment20 pages, 15 figures, 2 tables; in print in Astronomy & Astrophysics journal; minor typos corrected and a few references added

References in corpus (58)

• Stellar population synthesis at the resolution of 2003
• The Sloan Digital Sky Survey: Technical Summary
• The Seventh Data Release of the Sloan Digital Sky Survey
• A Fundamental Relation Between Supermassive Black Holes and Their Host Galaxies
• Coevolution (Or Not) of Supermassive Black Holes and Host Galaxies
• The Demography of Massive Dark Objects in Galaxy Centres
• The Host Galaxies of AGN
• Cosmic Star Formation History
• Theoretical Modeling of Starburst Galaxies
• The Host Galaxies and Classification of Active Galactic Nuclei
• Color Separation of Galaxy Types in the Sloan Digital Sky Survey Imaging Data
• Quantifying the bimodal color-magnitude distribution of galaxies
• The M-sigma and M-L Relations in Galactic Bulges and Determinations of their Intrinsic Scatter
• Towards a unified model for black hole X-ray binary jets
• Galaxy Luminosity Functions to z~1: DEEP2 vs. COMBO-17 and Implications for Red Galaxy Formation
• Present-Day Growth of Black Holes and Bulges: the SDSS Perspective
• Advection-Dominated Accretion: Self-Similarity and Bipolar Outflows
• Observational evidence for AGN feedback in early-type galaxies
• On the fundamental dichotomy in the local radio-AGN population: accretion, evolution, and host galaxy properties
• The bimodal galaxy color distribution: dependence on luminosity and environment
• Active Galactic Nuclei: what's in a name?
• Radio-Loudness of Active Galactic Nuclei: Observational Facts and Theoretical Implications
• Optical and Radio Properties of Extragalactic Sources Observed by the FIRST and SDSS Surveys
• The FIRST Bright Quasar Survey. II. 60 Nights and 1200 Spectra Later
• On the Relationship Between Radio Emission and Black Hole Mass in Galactic Nuclei
• Eigenvector 1: An Optimal Correlation Space for Active Galactic Nuclei
• The nature of LINER galaxies: Ubiquitous hot old stars and rare accreting black holes
• Radio Sources in Low-Luminosity Active Galactic Nuclei.IV. Radio Luminosity Function, Importance of Jet Power, and Radio Properties of the Complete Palomar Sample
• Dusty, Radiation Pressure Dominated Photoionization. I. Model Description, Structure And Grids
• Dusty, Radiation Pressure Dominated Photoionization. II. Multi-Wavelength Emission Line Diagnostics for Narrow Line Regions
• The 2dF QSO Redshift Survey - V. The 10k catalogue
• Searching for the Physical Drivers of the Eigenvector 1 Correlation Space
• Accretion Disk Model of Short-Timescale Intermittent Activity in Young Radio Sources
• Radio AGN in the local universe: unification, triggering and evolution
• Radio Loud and Radio Quiet Quasars
• Size and properties of the narrow-line region in Seyfert-1 galaxies from spatially-resolved optical spectroscopy
• AGNs and galaxy interactions
• Size and properties of the narrow-line region in Seyfert-2 galaxies from spatially-resolved optical spectroscopy
• On The Nature of Low Luminosity Narrow Line AGN
• Is there a Dichotomy in the Radio Loudness Distribution of Quasars?
• The Australia Telescope 20GHz (AT20G) Survey: analysis of the extragalactic source sample
• Quenching star formation: insights from the local main sequence
• The AGN fraction - velocity dispersion relation in clusters of galaxies
• The Radio Loud / Radio Quiet dichotomy: news from the 2dF QSO Redshift Survey
• Dissecting Galaxies: Spatial and Spectral Separation of Emission Excited by Star Formation and AGN Activity
• What drives the radio slopes in radio quiet quasars?
• Is there really a dichotomy in AGN jet power?
• AGN spectral states from simultaneous UV and X-ray observations by XMM-Newton
• Local and global environmental effects on galaxies and active galactic nuclei
• Extended narrow-line emission in the bright Seyfert 1.5 galaxy HE 2211-3903
• Interpreting the Ionization Sequence in Star-Forming Galaxy Emission-Line Spectra
• On the relation between Seyfert 2 accretion rate and environment at z < 0.1
• Dichotomy in host environments and signs of recycled AGN
• Galaxy evolution across the optical emission-line diagnostic diagrams?
• Occurrence of LINER galaxies within the galaxy group environment
• Classifying Radio Emitters from the Sloan Digital Sky Survey: Spectroscopy and Diagnostics
• A low-luminosity type-1 QSO sample; III. Optical spectroscopic properties and activity classification
• LINER galaxy properties and the local environment

Cited by in corpus (16)

• Stellar transits across a magnetized accretion torus as a mechanism for plasmoid ejection
• The Pan-STARRS1 z>5.6 quasar survey II: Discovery of 55 Quasars at 5.6<z<6.5
• Time-delay measurement of MgII broad line response for the highly-accreting quasar HE 0413-4031: Implications for the MgII-based radius-luminosity relation
• Completing the Census of AGN in GOODS-S/HUDF: New Ultra-Deep Radio Imaging and Predictions for JWST
• Linking the small scale relativistic winds and the large scale molecular outflows in the z = 1.51 lensed quasar HS 0810+2554
• Atacama Cosmology Telescope measurements of a large sample of candidates from the Massive and Distant Clusters of WISE Survey: Sunyaev-Zeldovich effect confirmation of MaDCoWS candidates using ACT
• Evolutionary Map of the Universe (EMU):Compact radio sources in the SCORPIO field towards the Galactic plane
• The GLEAM 200 MHz Local Radio Luminosity Function for AGN and Star-forming Galaxies
• J0011+3217: A peculiar radio galaxy with a one-sided secondary lobe and misaligned giant primary lobes
• Exploring the radio spectral energy distribution of the ultraluminous radio-quiet quasar SDSS J0100+2802 at redshift 6.3
• Multi-band optical variability of a newly discovered twelve blazars sample from 2013-2019
• A LOFAR sample of luminous compact sources coincident with nearby dwarf galaxies
• Non-thermal emission in galaxy groups at extremely low frequency: the case of A1213
• Revisiting the Dragonfly Galaxy I. High-resolution ALMA and VLA Observations of the Radio Hotspots in a Hyper-luminous Infrared Galaxy at $z=1.92$
• The 'spectral index-flux density relation' for extragalactic radio sources selected at metre and decametre wavelengths
• Structural and spectral properties of Galactic plane variable radio sources