RT Journal Article
T1 The nuclear activity and central structure of the elliptical galaxy NGC 5322
A1 Dullo, Bililign
A1 Knapen, Johan H.
A1 Williams, David R. A.
A1 Beswick, Robert J.
A1 Bendo, George
A1 Baldi, Ranieri D.
A1 Argo, Megan
A1 McHardy, Ian M.
A1 Muxlow, Tom
A1 Westcott, J.
AB We have analysed a new high-resolution e-MERLIN 1.5 GHz radio continuum map together with HST and SDSS imaging of NGC 5322, an elliptical galaxy hosting radio jets, aiming to understand the galaxy’s central structure and its connection to the nuclear activity. We decomposed the composite HST + SDSS surface brightness profile of the galaxy into an inner stellar disc, a spheroid, and an outer stellar halo. Past works showed that this embedded disc counter-rotates rapidly with respect to the spheroid. The HST images reveal an edge-on nuclear dust disc across the centre, aligned along the major-axis of the galaxy and nearly perpendicular to the radio jets. After careful masking of this dust disc, we find a central stellar mass deficit Mdef in the spheroid, scoured by SMBH binaries with final mass MBH such that Mdef/MBH ∼ 1.3–3.4. We propose a three-phase formation scenario for NGC 5322, where a few (2–7) ‘dry’ major mergers involving SMBHs built the spheroid with a depleted core. The cannibalism of a gas-rich satellite subsequently creates the faint counter-rotating disc and funnels gaseous material directly on to the AGN, powering the radio core with a brightness temperature of TB, core ∼ 4.5 × 107 K and the low-power radio jets (Pjets ∼ 7.04 × 1020 W Hz−1), which extend ∼1.6 kpc. The outer halo can later grow via minor mergers and the accretion of tidal debris. The low-luminosity AGN/jet-driven feedback may have quenched the late-time nuclear star formation promptly, which could otherwise have replenished the depleted core.
PB Oxford University Press
SN 0035-8711
YR 2018
FD 2018-01-10
LK https://hdl.handle.net/20.500.14352/88422
UL https://hdl.handle.net/20.500.14352/88422
LA eng
NO Dullo, B. T., Knapen, J. H., Williams, D. R., Beswick, R. J., Bendo, G., Baldi, R. D., ... & Westcott, J. (2018). The nuclear activity and central structure of the elliptical galaxy NGC 5322. Monthly Notices of the Royal Astronomical Society, 475(4), 4670-4682.
NO Spanish postdoctoral fellowship
NO Ministerio de Economía y Competitividad
NO Royal Society
NO Science & Technology Facilities Council (STFC)
NO Alfred P. Sloan Foundation
NO United States Department of Energy (DOE)
NO Brazilian Participation Group
NO Carnegie Institution for Science
NO Carnegie Mellon University
NO Chilean Participation Group
NO French Participation Group
NO Smithsonian Institution
NO Harvard-Smithsonian Center for Astrophysics
NO Instituto de Astrofisica de Canarias
NO Johns Hopkins University
NO Kavli Institute for the Physics and Mathematics of the Universe (IPMU) / University of Tokyo
NO United States Department of Energy (DOE)
NO Lawrence Berkeley National Laboratory
NO Leibniz Institut fur Astrophysik Potsdam (AIP)
NO Max-Planck-Institut fur Astronomie (MPIA Heidelberg)
NO Max-Planck-Institut fur Astrophysik (MPA Garching)
NO Max-Planck- Institut fur Extraterrestrische Physik (MPE)
NO National Astronomical Observatories of China
NO New Mexico State University
NO New York University
NO University of Notre Dame
NO Observatario Nacional/MCTI
NO Ohio State University
NO Pennsylvania State University
NO Shanghai Astronomical Observatory
NO United Kingdom Participation Group
NO Universidad Nacional Autónoma de Mexico
NO University of Arizona
NO University of Colorado Boulder
NO University of Oxford
NO University of Portsmouth
NO University of Utah
NO University of Virginia
NO University of Washington
NO University of Wisconsin
NO Vanderbilt University
NO Yale University
DS Docta Complutense
RD 9 may 2025