Intermediate-mass black holes: finding of episodic, large-scale, and powerful jet activity in a dwarf galaxy
Journal article, 2023
Dwarf galaxies are characterized by a very low luminosity and low mass. Because of significant accretion and ejection activity of massive black holes, some dwarf galaxies also host lo w-luminosity acti ve galactic nuclei (AGNs). In a few dwarf AGNs, very long baseline interferometry (VLBI) observations have found faint non-thermal radio emission. SDSS J090613.77 + 561015.2 is a dwarf AGN owning an intermediate-mass black hole (IMBH) with a mass of M-BH = 3 . 6 (+5.9) (-2.3 )x 10 (5) M(? )and showing a rarely seen two-component radio structure in its radio nucleus. To further probe their nature, i.e. the IMBH jet activity, we performed additional deep observations with the European VLBI Network (EVN) at 1.66 and 4.99 GHz. We find the more diffuse emission regions and structure details. These new EVN imaging results allow us to reveal a two-sided jet morphology with a size up to about 150 mas (projected length similar to 140 pc) and a radio luminosity of about 3 x 10( 38) erg s( -1). The peak feature has an optically thin radio spectrum and thus more likely represents a relatively young ejecta instead of a jet base. The EVN study on SDSS J090613.77 + 561015.2 demonstrates the existence of episodic, relatively large-scale, and powerful IMBH jet activity in dwarf AGNs. Moreo v er, we collected a small sample of VLBI-detected dwarf AGNs and investigated their connections with normal AGNs. We notice that these radio sources in the dwarf AGNs tend to have steep spectra and small linear sizes, and possibly represent ejecta from scaled-down episodic jet activity.
galaxies:individual:SDSS J090613.77+561015.2
galaxies:active
radio continuum:galaxies
galaxies:dwarf
individual
Author
Jun Yang
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Zsolt Paragi
Joint Institute for VLBI in Europe (JIVE)
Sandor Frey
Hungarian Academy of Sciences
Eötvös Loránd University (ELTE)
Research Centre for Astronomy and Earth Sciences
Gurvits
Joint Institute for VLBI in Europe (JIVE)
Delft University of Technology
Mai Liao
University of Science and Technology of China
Xiang Liu
Chinese Academy of Sciences
Lang Cui
Chinese Academy of Sciences
Xiaolong Yang
Chinese Academy of Sciences
Wen Chen
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Chinese Academy of Sciences
Eskil Varenius
Chalmers, Space, Earth and Environment, Geoscience and Remote Sensing
John Conway
Chalmers, Space, Earth and Environment, Onsala Space Observatory
Rurong Chen
Chinese Academy of Sciences
Ning Chang
Chinese Academy of Sciences
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 520 4 5964-5973Subject Categories
Subatomic Physics
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.1093/mnras/stad493