Revisiting the giant radio galaxy ESO 422-G028 - I. Discovery of a neutral inflow and recent star formation in a restarted giant - INSU - Institut national des sciences de l'Univers Accéder directement au contenu
Article Dans Une Revue Monthly Notices of the Royal Astronomical Society Année : 2022

Revisiting the giant radio galaxy ESO 422-G028 - I. Discovery of a neutral inflow and recent star formation in a restarted giant

Henry R. M. Zovaro
  • Fonction : Auteur
Chris J. Riseley
  • Fonction : Auteur
Philip Taylor
Tim J. Galvin
  • Fonction : Auteur
Umang Malik
  • Fonction : Auteur
Lisa J. Kewley
  • Fonction : Auteur

Résumé

Giant radio galaxies provide important clues into the life cycles and triggering mechanisms of radio jets. With large-scale jets spanning 1.8 Mpc, ESO 422-G028 (z = 0.038) is a giant radio galaxy that also exhibits signs of restarted jet activity in the form of pc-scale jets. We present a study of the spatially resolved stellar and gas properties of ESO 422-G028 using optical integral field spectroscopy from the Wide-Field Spectrograph (WiFeS). In addition to the majority ${\sim} 13\, \rm Gyr$ old stellar population, ESO 422-G028 exhibits a much younger (${\lesssim} 10\, \rm Myr$ old) component with an estimated mass of $10^{7.6}\, \rm M_\odot$ that is predominantly located in the north-west region of the galaxy. Unusually, the ionized gas kinematics reveal two distinct discs traced by narrow ($\sigma _{\rm H\alpha } 100 \, \rm km\, s^{-1}$) and broad ($\sigma _{\rm H\alpha } 150 \, \rm km\, s^{-1}$) Hα emission, respectively. Both ionized gas discs are misaligned with the axis of stellar rotation, suggesting an external origin. This is consistent with the prominent interstellar Na D absorption, which traces a $1 \!-\! 3 \, \rm M_\odot \, yr^{-1}$ inflow of neutral gas from the north. We posit that an inflow of gas - either from an accretion event or a gas-rich merger - has triggered both the starburst and the restarted jet activity, and that ESO 422-G028 is potentially on the brink of an epoch of powerful active galactic nucleus (AGN) activity.
Fichier principal
Vignette du fichier
stab3140.pdf (4.99 Mo) Télécharger le fichier
Origine Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

insu-03656925 , version 1 (07-04-2023)

Identifiants

Citer

Henry R. M. Zovaro, Chris J. Riseley, Philip Taylor, Nicole P. H. Nesvadba, Tim J. Galvin, et al.. Revisiting the giant radio galaxy ESO 422-G028 - I. Discovery of a neutral inflow and recent star formation in a restarted giant. Monthly Notices of the Royal Astronomical Society, 2022, 509, pp.4997-5017. ⟨10.1093/mnras/stab3140⟩. ⟨insu-03656925⟩
24 Consultations
26 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More