Galaxy archaeology for wet mergers: Globular cluster age distributions in the Milky Way and nearby galaxies

Abstract

Identifying past wet merger activity in galaxies has been a longstanding issue in extragalactic formation history studies. Gaia's 6D kinematic measurements in our Milky Way (MW) have vastly extended the possibilities for Galactic archaeology, leading to the discovery of early mergers in the MW's past. As recent work has established a link between young globular clusters (GCs) and wet galaxy merger events, the MW provides an ideal laboratory for testing how GCs can be used to trace galaxy formation histories. To test the hypothesis that GCs trace wet mergers, we relate the measured GC age distributions of the MW and three nearby galaxies to their merger histories and interpret the connection with wet mergers through an empirical model for GC formation. For the MW, we cross-match the GCs with their associated progenitor host galaxies to disentangle the connection to the GC age distribution. We find that the MW GC age distribution is bimodal, mainly caused by younger GCs associated with Gaia-Sausage/Enceladus (GSE) and in part by unassociated high-energy GCs. The GSE GC age distribution also appears to be bimodal. We propose that the older GSE GCs were accreted together with GSE, while the younger ones formed through the merger. For the nearby galaxies, we find that peaks in the GC age distributions coincide with early gas-rich mergers. Even small signatures in the GC age distributions agree well with the formation histories of the galaxies inferred through other observed tracers. From the models, we predict that the involved cold gas mass can be estimated from the number of GCs found in the formation burst. Multimodal GC age distributions can trace massive wet mergers as a result of GCs being formed through them. From the laboratory of our own MW and nearby galaxies we conclude that the ages of younger GC populations of galaxies can be used to infer the wet merger history of a galaxy.

18 pages, 14 figures, accepted for publication in A&A

References in corpus (58)

• Array Programming with NumPy
• Gaia Data Release 3: Summary of the content and survey properties
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• The ACS Survey of Galactic Globular Clusters. I. Overview and Clusters Without Previous HST Photometry
• Evidence for Two Early Accretion Events That Built the Milky Way Stellar Halo
• The accretion origin of the Milky Way's stellar halo
• Tracing Galaxy Formation with Stellar Halos II: Relating Substructure in Phase- and Abundance-Space to Accretion Histories
• An Orphan in the "Field of Streams"
• The SAGES Legacy Unifying Globulars and GalaxieS Survey (SLUGGS): Sample definition, methods, and initial results
• The Global Dynamical Atlas of the Milky Way mergers: Constraints from Gaia EDR3 based orbits of globular clusters, stellar streams and satellite galaxies
• Reverse engineering the Milky Way
• Galactic Dark Matter Halos and Globular Cluster Populations. III: Extension to Extreme Environments
• The chemical characterisation of halo substructure in the Milky Way based on APOGEE
• The Fall of a Giant. Chemical evolution of Enceladus, alias the Gaia Sausage
• The outer halo globular cluster system of M31 - I. The final PAndAS catalogue
• Modeling the Formation of Globular Cluster Systems in the Virgo Cluster
• Dark Matter Halos in Galaxies and Globular Cluster Populations. II: Metallicity and Morphology
• The Chemical Compositions of Accreted and {\it in situ} Galactic Globular Clusters According to SDSS/APOGEE
• galstreams: A Library of Milky Way Stellar Stream Footprints and Tracks
• On feathers, bifurcations and shells: the dynamics of tidal streams across the mass scale
• The Nature and Origin of Substructure in the Outskirts of M31 -- II. Detailed Star Formation Histories
• The formation of low metallicity globular clusters in dwarf galaxy mergers
• Whiting 1: the youngest globular cluster associated with the Sgr dSph
• The Gaia DR3 view of dynamical substructure in the stellar halo near the Sun
• Combining Stellar Populations with Orbit-Superposition Dynamical Modelling - the Formation History of the Lenticular Galaxy NGC 3115
• The Next Generation Virgo cluster Survey. V. modelling the dynamics of M87 with the Made-to-Measure method
• Chasing the impact of the Gaia-Sausage-Enceladus merger on the formation of the Milky Way thick disc
• Globular Clusters in the Outer Galactic Halo: AM-1 and Palomar 14
• The early-type galaxies NGC 1407 and NGC 1400 - II: star formation and chemical evolutionary history
• The distribution of globular clusters in kinematic spaces does not trace the accretion history of the host galaxy
• The Absolute Age of M92
• The globular cluster AM 4: yet another young globular associated with the Sgr Dwarf Spheroidal galaxy?
• The Local Stellar Halo is Not Dominated by a Single Radial Merger Event
• Discovery of the Magellanic Stellar Stream Out to 100 Kiloparsecs
• Formation of globular clusters in dwarf galaxies of the Local Group
• The complex stellar system M 22: confirming abundance variations with high precision differential measurements
• Globular cluster numbers in dark matter haloes in a dual formation scenario: an empirical model within EMERGE
• A Swing of the Pendulum: The Chemodynamics of the Local Stellar Halo Indicate Contributions from Several Radial Merger Events
• How well can we determine ages and chemical abundances from spectral fitting of integrated light spectra?
• Deriving ages and horizontal branch properties of integrated stellar populations
• Modeling the kinematics of globular cluster systems
• The SLUGGS survey: combining stars, globular clusters and planetary nebulae to understand the assembly history of early-type galaxies from their large radii kinematics
• Milky Way archaeology using RR Lyrae and type II Cepheids II. High velocity RR Lyrae stars, and mass of the Milky Way
• A stream come true: Connecting tidal tails, shells, streams, and planes with galaxy kinematics and formation history
• Modeling globular clusters in the TNG50 simulation: predictions from dwarfs to giants
• Simulations of globular clusters within their parent galaxies: multiple stellar populations and internal kinematics
• The survey of planetary nebulae in Andromeda (M31) VI. Kinematics of M31 inner-halo substructures and comparison with major-merger simulation predictions
• Catalogue of model star clusters in the Milky Way and M31 galaxies
• Unveiling the past evolution of the progenitor of the Helmi streams
• Recovering the origins of the lenticular galaxy NGC 3115 using multi-band imaging
• The assembly history of the nearest S0 galaxy NGC 3115 from its kinematics out to six half-light radii
• Estimating ages and metallicities of M31 star clusters from LAMOST DR6
• Rubin Observatory LSST Stars Milky Way and Local Volume Star Clusters Roadmap
• Spatially-resolved stellar populations and kinematics with KCWI: probing the assembly history of the massive early-type galaxy NGC 1407
• Spectral Energy Distributions and Masses of 304 M31 Old Star Clusters
• Star cluster formation from giant molecular clouds in the Small Magellanic Cloud about 2 Gyr ago: their origin, structures, and kinematics
• J-PLUS: Detecting and studying extragalactic globular clusters -- the case of NGC 1023
• Shapes of dark matter haloes with discrete globular cluster dynamics: The example of NGC 5128 (Centaurus A)

Cited by in corpus (7)

• Globular cluster ages and their relation to high-redshift stellar cluster formation times from different globular cluster models
• Major Mergers Mean Major Offset: Drivers of Intrinsic Scatter in The $M_{GCS}-M_h$ Scaling Relation for Massive Elliptical Galaxies
• Chronology of our Galaxy from Gaia colour-magnitude diagram fitting (ChronoGal) -- III. Age and metallicity distribution of Gaia-Sausage-Enceladus stars near the Sun
• A two-phase model of galaxy formation: III. The formation of globular clusters
• The Milky Way accretion history compared to cosmological simulations -- from bulge to dwarf galaxy infall
• Build-up and survival of the disc: From numerical models of galaxy formation to the Milky Way
• New Way to Date Globular Clusters: Brown Dwarf Cooling Sequences