A Recent Major Merger Tale for the Closest Giant Elliptical Galaxy Centaurus A

Abstract

We have used hydrodynamical simulations to model the formation of the closest giant elliptical galaxy, Centaurus A. We find that a single major merger event with a mass ratio up to 1.5, and which has happened ~2 Gyr ago, is able to reproduce many of its properties, including galaxy kinematics, the inner gas disk, stellar halo ages and metallicities, and numerous faint features observed in the halo. The elongated halo shape is mostly made of progenitor residuals deposited by the merger, which also contribute to stellar shells observed in the Centaurus A halo. The current model also reproduces the measured Planetary Nebulae line of sight velocity and their velocity dispersion. Models with small mass ratio and relatively low gas fraction result in a de Vaucouleurs profile distribution, which is consistent with observations and model expectations. A recent merger left imprints in the age distribution that are consistent with the young stellar and Globular Cluster populations (2-4 Gyrs) found within the halo. We conclude that even if not all properties of Centaurus A have been accurately reproduced, a recent major merger has likely occurred to form the Centaurus A galaxy as we observe it at present day.

Accepted for publication in Monthly Notices of the Royal Astronomical Society,13 pages, 9 figures

References in corpus (25)

• A Vast Thin Plane of Co-rotating Dwarf Galaxies Orbiting the Andromeda Galaxy
• The Haunted Halos of Andromeda and Triangulum: A panorama of galaxy formation in action
• A fitting formula for the merger timescale of galaxies in hierarchical clustering
• The Hubble flow around the CenA / M83 galaxy complex
• Co-orbiting satellite galaxy structures are still in conflict with the distribution of primordial dwarf galaxies
• The GIRAFFE Inner Bulge Survey (GIBS) III. Metallicity distributions and kinematics of 26 Galactic bulge fields
• The Radical Consequences of Realistic Satellite Orbits for the Heating and Implied Merger Histories of Galactic Disks
• A 2dF spectroscopic study of globular clusters in NGC 5128: Probing the formation history of the nearest giant Elliptical
• The failures of the standard model of cosmology require a new paradigm
• Open clusters in APOGEE and GALAH: Combining Gaia and ground-based spectroscopic surveys
• Truncations of stellar disk and warps of HI-layers in edge-on spiral galaxies
• Reproducing properties of MW dSphs as descendants of DM-free TDGs
• The Kinematics and Dynamics of the Globular Clusters and the Planetary Nebulae of NGC 5128
• Toward a Complete Understanding of the Magellanic Stream Formation
• Chemo-dynamical evolution of tidal dwarf galaxies. II. The long-term evolution and influence of a tidal field
• Tracing the outer halo in a giant elliptical to 25 Reff
• Loops formed by tidal tails as fossil records of a major merger
• The Centaurus Group and the Outer Halo of NGC 5128: Are they Dynamically Connected?
• The Complex North Transition Region of Centaurus A: A Galactic Wind
• Most pseudo-bulges can be formed at later stages of major mergers
• Stellar halos and elliptical galaxy formation: Origin of dynamical properties of the planetary nebular systems
• An imaging and spectroscopic study of the planetary nebulae in NGC 5128 (Centaurus A): Planetary nebulae catalogues
• On the globular cluster formation history of NGC 5128
• Red giants in the outer halo of the elliptical galaxy NGC 5128 / Centaurus A
• Refueled and shielded - The early evolution of Tidal Dwarf Galaxies

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• Reading the tea leaves in the $M_{\mathrm{bh}}$-$M_{\ast ,\mathrm{sph}}$ and $M_{\mathrm{bh}}$-$R_{\mathrm{e},\mathrm{sph}}$ diagrams: dry and gaseous mergers with remnant angular momentum
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• The satellite galaxy plane of NGC 4490 in light of ΛCDM - Sparsity of similarly extreme analogs and a possible role of satellite pairs
• Remnants of recent mergers in nearby early-type galaxies and their classification
• The imprint of galaxy mergers on satellite planes in a cosmological context
• Classifying the satellite plane membership of Centaurus A's dwarf galaxies using orbital alignment constraints
• New dwarf galaxy candidates in the sphere of influence of the Local Volume spiral galaxy NGC2683
• UVIT view of Centaurus A; a detailed study on positive AGN feedback
• The interplay between radio AGN activity and their host galaxies
• New Velocity Measurements of NGC 5128 Globular Clusters out to 130 kpc: Outer Halo Kinematics, Substructure and Dynamics
• Investigating the Dark Matter Halo of NGC 5128 using a Discrete Dynamical Model
• Is the correlation between the bulge-to-total stellar mass ratio and the number of dwarf galaxies in tension with $\Lambda$CDM?
• Shapes of dark matter haloes with discrete globular cluster dynamics: The example of NGC 5128 (Centaurus A)
• The role of mass loss in constraining quenching time in dwarf galaxies from AGB and RGB star counts
• Echoes of the past: ultra-high energy cosmic rays accelerated by radio galaxies, scattered by starburst galaxies
• The Cen A galaxy group: dynamical mass and missing baryons
• The Metallicity Distribution Function in Outer Halo Fields of Simulated Elliptical Galaxies Compared to Observations of NGC 5128