LeMMINGs. Multiwavelength constraints on the co-existence of nuclear star clusters and AGN in nucleated galaxies
Journal article, 2024
The relation between nuclear star clusters (NSCs) and the growth of the central supermassive black holes (SMBHs), as well as their connection to the properties of the host galaxies, is crucial for understanding the evolution of galaxies. Recent observations have revealed that about 10 per cent of nucleated galaxies host hybrid nuclei, consisting of both NSCs and accreting SMBHs that power active galactic nuclei (AGNs). Motivated by the potential of the recently published multiwavelength data sets from LeMMINGs survey, here we present the most thorough investigation to date of the incidence of hybrid nuclei in a large sample of 100 nearby nucleated galaxies (10 E, 25 S0, 63 S, and 2 Irr), covering a wide range in stellar mass (M∗,gal ∼ 108.7 - 1012 M☉). We identify the nuclei and derive their properties by performing detailed 1D and 2D multicomponent decompositions of the optical and near-infrared HST stellar light distributions of the galaxies using Sérsic and core-Sérsic models. Our AGN diagnostics are based on homogeneously derived nuclear 1.5 GHz e-MERLIN radio, Chandra X-ray (0.3–10 keV), and optical emission-line data. We determine the nucleation fraction (fnuc) as the relative incidence of nuclei across the LeMMINGs HST sample and find fnuc = 100/149 (= 67 ± 7 per cent), confirming previous work, with a peak value of 49/56 (= 88 ± 13 per cent) at bulge masses M∗,bulge ∼ 109.4 - 1010.8 M☉. We identify 30 nucleated LeMMINGs galaxies that are optically active, radio-detected, and X-ray luminous (LX > 1039 erg s-1). This indicates that our nucleated sample has a lower limit ∼ 30 per cent occupancy of hybrid nuclei, which is a function of M∗,bulge and M∗,gal. We find that hybrid nuclei have a number density of (1.5 ± 0.4) × 10-5 Mpc-3, are more common at M∗,gal ∼ 1010.6 - 1011.8 M☉ and occur, at least, three times more frequently than previously reported.
galaxies: photometry
radio continuum: galaxies
cD
galaxies: elliptical and lenticular
galaxies: nuclei
galaxies: fundamental parameters
galaxies: structure
Author
B. T. Dullo
Complutense University
Embry-Riddle Aeronautical University
J. H. Knapen
University of La Laguna
Instituto de Astrofísica de Canarias
R. D. Baldi
University of Southampton
Istituto di Radioastronomia
D. R.A. Williams
University of Manchester
R. J. Beswick
University of Manchester
I. M. McHardy
University of Southampton
D. A. Green
University of Cambridge
A. Gil de Paz
IPARCOS-UCM (Instituto de Física de Partículas y del Cosmos)
Complutense University
Susanne Aalto
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Antxon Alberdi
Spanish National Research Council (CSIC)
M. K. Argo
University of Central Lancashire
J. S. Gallagher III
University of Wisconsin
H. R. Klockner
Max Planck Society
J.M. Marcaide
Real Academia de Ciencias Exactas, Físicas y Naturales de España
I. Mutie
University of Manchester
Technical University of Kenya
D. J. Saikia
Inter-University Centre for Astronomy and Astrophysics
P. Saikia
New York University Abu Dhabi
I. R. Stevens
University of Birmingham
S. Torrejón
Complutense University
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 532 4 4729-4751Subject Categories (SSIF 2011)
Subatomic Physics
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.1093/mnras/stae1732