Dynamical modelling of globular clusters: challenges for the robust determination of IMBH candidates

Abstract

The presence or absence of intermediate-mass black holes (IMBHs) at the centre of Milky Way globular clusters (GCs) is still an open question. This is either due to observational restrictions or limitations in the dynamical modelling method; in this work, we explore the latter. Using a sample of high-end Monte Carlo simulations of GCs, with and without a central IMBH, we study the limitations of spherically symmetric Jeans models assuming constant velocity anisotropy and mass-to-light ratio. This dynamical method is one of the most widely used modelling approaches to identify a central IMBH in observations. With these models, we are able to robustly identify and recover the mass of the central IMBH in our simulation with a high-mass IMBH ($M_{\mathrm{IMBH}}/M_{\mathrm{GC}}\sim 4\%$). Simultaneously, we show that it is challenging to confirm the existence of a low-mass IMBH ($M_{\mathrm{IMBH}}/M_{\mathrm{GC}}\sim 0.3\%$), as both solutions with and without an IMBH are possible within our adopted error bars. For simulations without an IMBH we do not find any certain false detection of an IMBH. However, we obtain upper limits which still allow for the presence of a central IMBH. We conclude that while our modelling approach is reliable for the high-mass IMBH and does not seem to lead towards a false detection of a central IMBH, it lacks the sensitivity to robustly identify a low-mass IMBH and to definitely rule out the presence of an IMBH when it is not there.

Accepted for publication in MNRAS. 21 pages, 20 figures. The main results can be seen in figures 9 and 10. Figures 4, 14 and A2 bring interesting points for discussion

References in corpus (88)

• emcee: The MCMC Hammer
• The NumPy array: a structure for efficient numerical computation
• Evolution of binary stars and the effect of tides on binary populations
• Comprehensive analytic formulae for stellar evolution as a function of mass and metallicity
• A statistical study of 233 pulsar proper motions
• GW190521: A Binary Black Hole Merger with a Total Mass of $150M_{\odot }$
• A Comprehensive Study of Binary Compact Objects as Gravitational Wave Sources: Evolutionary Channels, Rates, and Physical Properties
• Massive Black Holes as Population III Remnants
• Extragalactic Globular Clusters and Galaxy Formation
• The formation of massive black holes through collision runaway in dense young star clusters
• Properties and astrophysical implications of the 150 Msun binary black hole merger GW190521
• An Intermediate-mass Black Hole of Over 500 Solar Masses in the Galaxy ESO 243-49
• The ACS Survey of Galactic Globular Clusters. XII. Photometric Binaries along the Main-Sequence
• Unresolved stellar companions with Gaia DR2 astrometry
• Distances, ages, and epoch of formation of globular clusters
• MOCCA-SURVEY Database I: Coalescing Binary Black Holes Originating From Globular Clusters
• Very massive stars, pair-instability supernovae and intermediate-mass black holes with the SEVN code
• Stellar Collisions During Binary-Binary and Binary-Single Star Interactions
• The Dynamical Evolution of Stellar Black Holes in Globular Clusters
• The DRAGON simulations: globular cluster evolution with a million stars
• Two stellar-mass black holes in the globular cluster M22
• A black hole in a globular cluster
• MOCCA Code for Star Cluster Simulations - IV. A new Scenario for Intermediate Mass Black Hole Formation in Globular Clusters
• Gemini and Hubble Space Telescope Evidence for an Intermediate Mass Black Hole in omega Centauri
• New Limits on an Intermediate Mass Black Hole in Omega Centauri: I. Hubble Space Telescope Photometry and Proper Motions
• The Time Scale of Escape from Star Clusters
• New Limits on an Intermediate Mass Black Hole in Omega Centauri: II. Dynamical Models
• A detached stellar-mass black hole candidate in the globular cluster NGC 3201
• A 20 Thousand Solar Mass Black Hole in the Stellar Cluster G1
• A stellar census in globular clusters with MUSE: The contribution of rotation to cluster dynamics studied with 200 000 stars
• N-body modeling of globular clusters: Masses, mass-to-light ratios and intermediate-mass black holes
• Dynamical evolution of black hole sub-systems in idealised star clusters
• An intermediate-mass black hole in the centre of the globular cluster 47 Tucanae
• A Multi-Mass Velocity Dispersion Model of 47 Tucanae Indicates No Evidence for an Intermediate Mass Black Hole
• Scaling of N-body calculations
• A stellar census in globular clusters with MUSE: Binaries in NGC 3201
• MOCCA Code for Star Cluster Simulations - II. Comparison with N-body Simulations
• MOCCA code for star cluster simulations - I. Blue Stragglers, first results
• A Radio-Selected Black Hole X-ray Binary Candidate in the Milky Way Globular Cluster M62
• Retention of Stellar-Mass Black Holes in Globular Clusters
• VLT Kinematics for omega Centauri: Further Support for a Central Black Hole
• Deep radio imaging of 47 Tuc identifies the peculiar X-ray source X9 as a new black hole candidate
• MOCCA-SURVEY Database I: Galactic Globular Clusters Harbouring a Black Hole Subsystem
• No Energy Equipartition in Globular Clusters
• The velocity dispersion profile of NGC 6388 from resolved-star spectroscopy: no evidence of a central cusp and new constraints on the black hole mass
• Limits on intermediate-mass black holes in six Galactic globular clusters with integral-field spectroscopy
• The MAVERIC Survey: Still No Evidence for Accreting Intermediate-mass Black Holes in Globular Clusters
• MOCCA-SURVEY Database I. Unravelling black hole subsystems in globular clusters
• Kinematic signature of an intermediate-mass black hole in the globular cluster NGC 6388
• How initial size governs core collapse in globular clusters
• The ultracompact nature of the black hole candidate X-ray binary 47 Tuc X9
• How to break the density-anisotropy degeneracy in spherical stellar systems
• A novel look at energy equipartition in globular clusters
• Multiple stellar-mass black holes in globular clusters: theoretical confirmation
• The Formation of the First Massive Black Holes
• On the coexistence of stellar-mass and intermediate-mass black holes in globular clusters
• MUSE crowded field 3D spectroscopy of over 12,000 stars in the globular cluster NGC 6397 - II. Probing the internal dynamics and the presence of a central black hole
• The effect of stellar-mass black holes on the central kinematics of omega Cen: a cautionary tale for IMBH interpretations
• Hubble Space Telescope Proper motion (HSTPROMO) Catalogs of Galactic Globular Clusters. VI. Improved data reduction and internal-kinematic analysis of NGC 362
• Hubble Space Telescope proper motion (HSTPROMO) catalogs of Galactic globular clusters. III. Dynamical distances and mass-to-light ratios
• Intermediate Mass Black Hole Induced Quenching of Mass Segregation in Star Clusters
• No evidence for intermediate-mass black holes in the globular clusters $\omega$ Cen and NGC 6624
• Globular Clusters with Dark Matter Halos. I. Initial Relaxation
• A Dynamical Survey of Stellar-Mass Black Holes in 50 Milky Way Globular Clusters
• Monte Carlo simulations of star clusters - II. Tidally limited, multi-mass systems with stellar evolution
• Monte Carlo Simulations of Star Clusters - V. The globular cluster M4
• Radial anisotropy in omega Cen limiting the room for an intermediate-mass black hole
• The Maveric Survey: a Red Straggler Binary with an Invisible Companion in the Galactic Globular Cluster M10
• Predicting Stellar-Mass Black Hole Populations in Globular Clusters
• On black hole sub-systems in idealized nuclear star clusters
• Central kinematics of the globular cluster NGC 2808: Upper limit on the mass of an intermediate-mass black hole
• On the black hole content and initial mass function of 47 Tuc
• Monte-Carlo Simulations of Star Clusters I. First Results
• Mass Evaporation Rate of Globular Clusters in a Strong Tidal Field
• MOCCA code for star cluster simulations - III. Stellar-mass black holes in the globular cluster M22
• The central dynamics of M3, M13, and M92: Stringent limits on the masses of intermediate-mass black holes
• Exploring the outskirts of globular clusters: the peculiar kinematics of NGC 3201
• A re-evaluation of the central velocity-dispersion profile in NGC 6388
• Mass modelling globular clusters in the Gaia era: a method comparison using mock data from an $N$-body simulation of M4
• Deep HST Imaging in 47 Tucanae: A Global Dynamical Model
• MOCCA-SURVEY Database I. Intermediate mass black holes in Milky Way globular clusters and their connection to supermassive black holes
• The relation between the mass-to-light ratio and the relaxation state of globular clusters
• The effect of unresolved binaries on globular cluster proper-motion dispersion profiles
• Understanding the central kinematics of globular clusters with simulated integrated-light IFU observations
• Prospects for detection of intermediate-mass black holes in globular clusters using integrated-light spectroscopy
• X-ray Variability from the Ultraluminous Black Hole Candidate X-ray Binary in the Globular Cluster RZ 2109
• Wandering off the centre: a characterization of the random motion of intermediate-mass black holes in star clusters
• COCOA Code for Creating Mock Observations of Star Cluster Models

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• Dynamical analysis of the dark matter and central black hole mass in the dwarf spheroidal Leo I
• An elusive dark central mass in the globular cluster M4
• MOCCA-SURVEY Database II -- Properties of Intermediate Mass Black Holes escaping from star clusters
• A Deep View into the Nucleus of the Sagittarius Dwarf Spheroidal Galaxy with MUSE. III. Discrete multi-component population-dynamical models based on the Jeans equations
• Dynamics of star clusters with tangentially anisotropic velocity distribution
• Dynamics of intermediate mass black holes in globular clusters. Wander radius and anisotropy profiles
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• Evolution towards energy equipartition in star clusters: effects of the tidal field, primordial binaries, and internal velocity anisotropy
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