The young nuclear stellar disc in the SB0 galaxy NGC 1023

Abstract

Small kinematically-decoupled stellar discs with scalelengths of a few tens of parsec are known to reside in the centre of galaxies. Different mechanisms have been proposed to explain how they form, including gas dissipation and merging of globular clusters. Using archival Hubble Space Telescope imaging and ground-based integral-field spectroscopy, we investigated the structure and stellar populations of the nuclear stellar disc hosted in the interacting SB0 galaxy NGC 1023. The stars of the nuclear disc are remarkably younger and more metal rich with respect to the host bulge. These findings support a scenario in which the nuclear disc is the end result of star formation in metal enriched gas piled up in the galaxy centre. The gas can be of either internal or external origin, i.e. from either the main disc of NGC 1023 or the nearby satellite galaxy NGC 1023A. The dissipationless formation of the nuclear disc from already formed stars, through the migration and accretion of star clusters into the galactic centre is rejected.

11 pages, 5 figures, MNRAS in press, updated references

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Cited by in corpus (8)

• The SLUGGS survey: combining stars, globular clusters and planetary nebulae to understand the assembly history of early-type galaxies from their large radii kinematics
• LLAMA: Nuclear stellar properties of Swift BAT AGN and matched inactive galaxies
• Disc galaxies are still settling: The discovery of the smallest nuclear discs and their young stellar bars
• Nuclear discs as clocks for the assembly history of early-type galaxies: the case of NGC4458
• The kinematics of σ-drop bulges from spectral synthesis modelling of a hydrodynamical simulation
• The fragility of thin discs in galaxies -- I. Building tailored N-body galaxy models
• The fragility of thin discs in galaxies -- II. Thin discs as tracers of the assembly history of galaxies
• Detectability of large-scale counter-rotating stellar disks in galaxies with integral-field spectroscopy