Are we observing a NSC in course of formation in the NGC 4654 galaxy?

Abstract

We use direct $N$-body simulations to explore some possible scenarios for the future evolution of two massive clusters observed toward the center of NGC\,4654, a spiral galaxy with mass similar to that of the Milky Way. Using archival HST data, we obtain the photometric masses of the two clusters, $M=3\times 10^5$ M${}_{\odot }$ and $M=1.7\times 10^6$ M${}_{\odot }$, their half-light radii, $R_{\mathrm{eff}}\sim 4$ pc and $R_{\mathrm{eff}}\sim 6$ pc, and their projected distances from the photometric center of the galaxy (both $<22$ pc). The knowledge of the structure and separation of these two clusters ($\sim 24$ pc) provides a unique view for studying the dynamics of a galactic central zone hosting massive clusters. Varying some of the unknown clusters orbital parameters, we carry out several $N$-body simulations showing that the future evolution of these clusters will inevitably result in their merger. We find that, mainly depending on the shape of their relative orbit, they will merge into the galactic center in less than 82 Myr. In addition to the tidal interaction, a proper consideration of the dynamical friction braking would shorten the merging times up to few Myr. We also investigate the possibility to form a massive NSC in the center of the galaxy by this process. Our analysis suggests that for low eccentricity orbits, and relatively long merger times, the final merged cluster is spherical in shape, with an effective radius of few parsecs and a mass within the effective radius of the order of $10^5{\mathrm{M}}_{\odot }$. Because the central density of such a cluster is higher than that of the host galaxy, it is likely that this merger remnant could be the likely embryo of a future NSC.

arXiv comment10 Pages, 11 Figures, 2 Tables. Published in MNRAS

References in corpus (39)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Stellar population synthesis at the resolution of 2003
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• Correcting for the Effects of Interstellar Extinction
• HyperLEDA. III. The catalogue of extragalactic distances
• Empirical models for Dark Matter Halos. I. Nonparametric Construction of Density Profiles and Comparison with Parametric Models
• The ACS Virgo Cluster Survey. VIII. The Nuclei of Early-Type Galaxies
• Nuclear Star Clusters
• An HST Census of Nuclear Star Clusters in Late-Type Spiral Galaxies: I. Observations and Image Analysis
• Modelling the nebular emission from primeval to present-day star-forming galaxies
• Imfit: A Fast, Flexible New Program for Astronomical Image Fitting
• A HST Census of Nuclear Star Clusters in Late-Type Spiral Galaxies: II. Cluster Sizes and Structural Parameter Correlations
• HST/STIS Spectra of Nuclear Star Clusters in Spiral Galaxies: Dependence of Age and Mass On Hubble Type
• Dissipationless Formation and Evolution of the Milky Way Nuclear Star Cluster
• Co-Evolution of Galactic Nuclei and Globular Cluster Systems
• Nuclear star clusters in 228 spiral galaxies in the HST/WFPC2 archive: catalogue and comparison to other stellar systems
• The NGC 404 Nucleus: Star Cluster and Possible Intermediate Mass Black Hole
• The specific entropy of elliptical galaxies: an explanation for profile-shape distance indicators?
• Origin and growth of nuclear star clusters around massive black holes
• The Evolution of the Globular Cluster System in a Triaxial Galaxy: Can a Galactic Nucleus Form by Globular Cluster Capture?
• The ACS Fornax Cluster Survey. VI. The Nuclei of Early-Type Galaxies in the Fornax Cluster
• The Next Generation Virgo Cluster Survey. XXIII. Fundamentals of nuclear star clusters over seven decades in galaxy mass
• The HST/ACS Coma Cluster Survey. X. Nuclear star clusters in low-mass early-type galaxies: scaling relations
• The Globular Cluster Migratory Origin of Nuclear Star Clusters
• Self-consistent simulations of Nuclear Cluster formation through Globular Cluster orbital decay and merging
• Merging of globular clusters within inner galactic regions. II. The Nuclear Star Cluster formation
• A fully parallel, high precision, N-body code running on hybrid computing platforms
• On the rotation of nuclear star clusters formed by cluster-inspirals
• Two-dimensional H_alpha kinematics of bulgeless disk galaxies
• Virgo Redux: The Masses and Stellar Content of Nuclei in Early-Type Galaxies from Multi-Band Photometry and Spectroscopy
• Luminosity Models and Density Profiles for Nuclear Star Clusters for a Nearby Volume-Limited Sample of 29 Galaxies
• Asymmetric spatial distribution of sub-solar metallicity stars in the Milky Way nuclear star cluster
• On the origin of a rotating metal-poor stellar population in the Milky Way Nuclear Cluster
• On the relation between the mass of Compact Massive Objects and their host galaxies
• AMUSE-Field II. Nucleation of early-type galaxies in the field vs. cluster environment
• The MEGaN project I. Missing formation of massive nuclear clusters and tidal disruption events by star clusters - massive black hole interactions
• Globular clusters as tracers of the host galaxy mass distribution: the Fornax dSph test case
• A Counterpart to the Radial Orbit Instability in Triaxial Stellar Systems
• The Milky Way like galaxy NGC 6384 and its nuclear star cluster at high NIR spatial resolution using LBT/ARGOS commissioning data

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• Dwarf galaxies in the MATLAS Survey: Hubble Space Telescope observations of nuclear star clusters
• Galaxy mass dependence of metal-enrichment of nuclear star clusters