J/A+A/689/A34 Efficiency of black hole formation (Vergara+, 2024)
Efficiency of black hole formation via collisions in stellar systems:
Data analysis from simulations and observations.
Vergara M.C., Schleicher D.R.G., Escala A., Reinoso B., Flammini Dotti F.,
Kamlah A.W.H., Liempi M., Hoyer N., Neumayer N., Spurzem R.
<Astron. Astrophys. 689, A34 (2024)>
=2024A&A...689A..34V 2024A&A...689A..34V (SIMBAD/NED BibCode)
ADC_Keywords: Models ; Black holes ; QSOs ; Associations, stellar ;
Stars, masses
Keywords: galaxies: clusters: general - galaxies: nuclei -
quasars: supermassive black holes
Abstract:
This paper explores the theoretical relation between star clusters and
black holes within, focusing on the potential role of Nuclear Star
Clusters (NSCs), Globular Clusters (GCs), and Ultra Compact Dwarf
Galaxies (UCDs) as environments that lead to black hole formation
through stellar collisions. The study aims to identify optimal
conditions for stellar collisions in different stellar systems leading
to the formation of very massive stars that subsequently collapse into
black holes. Data from numerical simulations and observations of
diverse stellar systems are analyzed, encompassing various initial
conditions, initial mass functions, and stellar evolution scenarios.
We compute a critical mass, determined by the interplay of collision
time, system age, and initial properties of the star cluster. The
efficiency of black hole formation (εBH) is defined as the
ratio of initial stellar mass divided by critical mass. The study
finds out that stellar systems with a ratio of initial stellar mass
over critical mass above 1 exhibit high efficiencies of black hole
formation, ranging from 30-100%. While there is some scatter,
potentially attributed to complex system histories and the presence of
gas, the results highlight the potential for achieving high
efficiencies through a purely collisional channel in black hole
formation. In conclusion, this theoretical exploration elucidates the
connection between star clusters and black hole formation. The study
underscores the significance of UCDs, GCs, and NSCs as environments
conducive to stellar collisions leading to black hole formation. The
defined black hole formation efficiency (εBH) is shown to
be influenced by the ratio of initial stellar mass to critical mass.
Description:
Summary of the initial conditions for the different sets of simulations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 66 164 Initial conditions for simulation sets
table2.dat 69 28 Initial conditions for simulation sets with
external potential
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.2 Msun Mini Initial mass
14- 18 F5.3 pc Rh Half-Mass radius
26- 32 I7 --- N Number of stars
34- 41 F8.2 Msun MBH Black hole mass
47- 53 F7.2 Myr tau Simulation time
55- 58 A4 --- Code Code name (G1)
62- 66 A5 --- Ref Reference (G2)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 Msun Mini Initial mass
17- 20 F4.2 pc Rh Half-Mass radius
29- 32 I4 --- N Number of stars
35- 38 I4 Msun MBH Black hole mass
48- 52 F5.2 Myr tau Simulation time
55- 57 F3.1 --- q Mass ratio between gas and stars
60- 62 A3 --- Code Code name (G1)
66- 69 A4 --- Ref Reference (G2)
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Global notes:
Note (G1): Code as follows:
B = bridge
SL = starlab
NB6 = nbody6
NB6+ = nbody6++gpu
BF = bifrost
Note (G2): References as follows:
P+99 = Portegies Zwart et al. (1999A&A...348..117P 1999A&A...348..117P)
F+13 = Fujii & Portegies Zwart (2013MNRAS.430.1018F 2013MNRAS.430.1018F)
K+15 = Katz et al. (2015MNRAS.451.2352K 2015MNRAS.451.2352K)
M+16 = Mapelli (2016MNRAS.459.3432M 2016MNRAS.459.3432M)
S+17 = Sakurai et al. (2017MNRAS.472.1677S 2017MNRAS.472.1677S)
R+18 = Reinoso et al. (2018A&A...614A..14R 2018A&A...614A..14R)
P+19 = Panamarev et al. (2019MNRAS.484.3279P 2019MNRAS.484.3279P)
R+20 = Reinoso et al. (2020A&A...639A..92R 2020A&A...639A..92R)
V+21 = Vergara et al. (2021A&A...649A.160V 2021A&A...649A.160V)
V+23 = Vergara et al. (2023MNRAS.522.4224V 2023MNRAS.522.4224V)
AS+23 = Arca Sedda et al. (2023, arXiv e-prints, arXiv:2307.04805,
arXiv:2307.04806, arXiv:2307.04807)
R+23 = Rizzuto et al. (2023MNRAS.521.2930R 2023MNRAS.521.2930R)
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Acknowledgements:
Marcelo C. Vergara, marcelo.c.vergara(at)uni-heidelberg.de
(End) Marcelo C. Vergara [Univ. Heidelberg], Patricia Vannier [CDS] 10-Jun-2024