scholarly journals Globular Clusters with Dark Matter Halos. II. Evolution in a Tidal Field

2005 ◽  
Vol 619 (1) ◽  
pp. 258-269 ◽  
Author(s):  
Sergey Mashchenko ◽  
Alison Sills
Keyword(s):  
Dark Matter ◽  
Globular Clusters ◽  
Dark Matter Halos

scholarly journals EVIDENCE AGAINST DARK MATTER HALOS SURROUNDING THE GLOBULAR CLUSTERS MGC1 AND NGC 2419

2011 ◽  
Vol 741 (2) ◽  
pp. 72 ◽  
Author(s):  
Charlie Conroy ◽  
Abraham Loeb ◽  
David N. Spergel
Keyword(s):  
Dark Matter ◽  
Globular Clusters ◽  
Dark Matter Halos

scholarly journals Tidal Disruption of Dark Matter Halos around Proto–Globular Clusters

2006 ◽  
Vol 640 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Takayuki R. Saitoh ◽  
Jin Koda ◽  
Takashi Okamoto ◽  
Keiichi Wada ◽  
Asao Habe
Keyword(s):  
Dark Matter ◽  
Globular Clusters ◽  
Dark Matter Halos ◽  
Tidal Disruption

scholarly journals The Faint Globular Cluster in the Dwarf Galaxy Andromeda I

2017 ◽  
Vol 34 ◽  
Author(s):  
Nelson Caldwell ◽  
Jay Strader ◽  
David J. Sand ◽  
Beth Willman ◽  
Anil C. Seth
Keyword(s):  
Dark Matter ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Local Group ◽  
Dwarf Galaxies ◽  
Dwarf Galaxy ◽  
Dark Matter Halos ◽  
History Of ◽  
Low Mass ◽  
Growing Population

AbstractObservations of globular clusters in dwarf galaxies can be used to study a variety of topics, including the structure of dark matter halos and the history of vigorous star formation in low-mass galaxies. We report on the properties of the faint globular cluster (MV ~ −3.4) in the M31 dwarf galaxy Andromeda I. This object adds to the growing population of low-luminosity Local Group galaxies that host single globular clusters.

scholarly journals Globular Clusters and Streaming Velocities: Testing the New Formation Channel in High-resolution Cosmological Simulations

2021 ◽  
Vol 922 (2) ◽  
pp. 193
Author(s):  
Anna T. P. Schauer ◽  
Volker Bromm ◽  
Michael Boylan-Kolchin ◽  
Simon C. O. Glover ◽  
Ralf S. Klessen
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Globular Clusters ◽  
Large Scale ◽  
Compact Star ◽  
Star Clusters ◽  
Dark Matter Halos ◽  
Metal Enrichment ◽  
Hydrodynamical Simulations ◽  
Population Iii

Abstract The formation of globular clusters and their relation to the distribution of dark matter have long puzzled astronomers. One of the most recently proposed globular cluster formation channels ties ancient star clusters to the large-scale streaming velocity of baryons relative to dark matter in the early universe. These streaming velocities affect the global infall of baryons into dark matter halos, the high-redshift halo mass function, and the earliest generations of stars. In some cases, streaming velocities may result in dense regions of dark matter-free gas that becomes Jeans unstable, potentially leading to the formation of compact star clusters. We investigate this hypothesis using cosmological hydrodynamical simulations that include a full chemical network and the formation and destruction of H2, a process crucial for the formation of the first stars. We find that high-density gas in regions with significant streaming velocities is indeed somewhat offset from the centers of dark matter halos, but this offset is typically significantly smaller than the virial radius. Gas outside of dark matter halos never reaches Jeans-unstable densities in our simulations. We postulate that low-level (Z ≈ 10−3 Z ⊙) metal enrichment by Population III supernovae may enable cooling in the extra-virial regions, allowing gas outside of dark matter halos to cool to the cosmic microwave background temperature and become Jeans unstable. Follow-up simulations that include both streaming velocities and metal enrichment by Population III supernovae are needed to understand if streaming velocities provide one path for the formation of globular clusters in the early universe.

scholarly journals Globular Clusters with Dark Matter Halos. I. Initial Relaxation

2005 ◽  
Vol 619 (1) ◽  
pp. 243-257 ◽  
Author(s):  
Sergey Mashchenko ◽  
Alison Sills
Keyword(s):  
Dark Matter ◽  
Globular Clusters ◽  
Dark Matter Halos

scholarly journals Globular Clusters within Dark Matter Halos: Case Studies of 47 Tuc, NGC 1851 and M 15

2015 ◽  
Vol 12 (S316) ◽  
pp. 336-337
Author(s):  
Joowon Lee ◽  
Jihye Shin ◽  
Sungsoo S. Kim
Keyword(s):  
Dark Matter ◽  
Case Studies ◽  
Globular Clusters ◽  
Dynamical Evolution ◽  
Stellar Mass ◽  
Dark Matter Halos ◽  
Dynamical Processes ◽  
Mass Segregation ◽  
Fokker Planck

AbstractGlobular clusters (GCs) are known to have a very small amount of or no dark matter (DM). Even if GCs are formed in individual DM halos, they must have lost the majority of the DM through dynamical processes such as mass segregation or tidal stripping. Using Fokker-Planck (FP) calculations, we investigate the dynamical evolution of three Galactic GCs with an assumption that they were formed in mini DM halos. We trace the amount of DM of 47 Tuc, NGC 1851, and M 15, which are a ‘disk/bulge’ cluster, an ‘old halo’ cluster, and a ‘young halo’ cluster, respectively. We find that these three GCs must have initially had insignificant amounts of DM, less than 10 percent of the initial stellar mass of each cluster.

scholarly journals Dynamical Friction in dE Globular Cluster Systems

2002 ◽  
Vol 207 ◽  
pp. 593-598
Author(s):  
Jennifer M. Lotz ◽  
Bryan W. Miller ◽  
Henry C. Ferguson ◽  
Massimo Stiavelli ◽  
Rosemary Telford
Keyword(s):  
Dark Matter ◽  
Globular Cluster ◽  
Globular Clusters ◽  
Elliptical Galaxy ◽  
Dark Matter Halos ◽  
Dynamical Friction ◽  
Cluster Systems ◽  
Tidal Interactions ◽  
Radial Density Profile ◽  
Fornax Cluster

The dynamical friction timescale for globular clusters to sink to the center of a dwarf elliptical galaxy (dE) is significantly less than a Hubble time if the halos have isothermal profiles and the globular clusters formed with the same radial density profile as the underlying stellar population. We examine the summed radial distribution of the entire globular cluster systems and the bright globular cluster candidates in 65 Virgo and Fornax Cluster dEs for evidence of dynamical friction processes. We find that the bright dE nuclei could have been formed from the merger of orbitally decayed massive clusters, but the faint nuclei are several magnitudes fainter than expected. These faint nuclei are found primarily in MV > −14 dEs which have high globular cluster specific frequencies and extended globular cluster systems. In these galaxies, the formation of new star clusters, high central dark matter densities, extended dark matter halos, or tidal interactions may act to prevent dynamical friction from collapsing the entire globular cluster population into a bright nucleus.

scholarly journals Limits on the dark matter content of globular clusters

2009 ◽  
Vol 5 (S266) ◽  
pp. 365-365
Author(s):  
H. Baumgardt ◽  
P. Côté ◽  
M. Hilker ◽  
M. Rejkuba ◽  
S. Mieske ◽  
...  
Keyword(s):  
Dark Matter ◽  
Globular Clusters ◽  
Stellar Population ◽  
Velocity Dispersion ◽  
Large Mass ◽  
Matter Content ◽  
Dark Matter Halo ◽  
Dark Matter Halos ◽  
Galactocentric Distance ◽  
Rule Out

AbstractWe have measured the velocity dispersion of the Galactic globular cluster NGC 2419 to determine if a substantial amount of dark matter is present in this cluster. NGC 2419 is one of the best globular clusters to look for dark matter due to its large mass, long relaxation time and large Galactocentric distance, which makes tidal stripping of dark matter unlikely. Our results can be summarized as follows. (i) We found a global velocity dispersion of 4.14 ± 0.48 km s−1, which leads to a total cluster mass of (9.02 ± 2.22) × 105 M⊙ and implies a global mass-to-light ratio of 2.05 ± 0.50 M⊙/L⊙. (ii) Our derived mass-to-light ratio is completely consistent with the mass-to-light ratio of a standard stellar population at the metallicity and age of NGC 2419. In addition, the mass-to-light ratio of NGC 2419 does not increase towards the outer cluster parts. (iii) We can therefore rule out the presence of a dark-matter halo with a central density greater than about 0.02 M⊙ pc−3. Similar limits are found for other halo globular clusters, like Pal 14. These observations therefore indicate that NGC 2419 and other halo globular clusters did not form at the centers of dark-matter halos similar to those surrounding dwarf galaxies. Instead, an origin driven by gas-dynamical processes during mergers between galaxies or proto-galactic fragments seems to be the more likely explanation for the formation of even the lowest-metallicity globular clusters.

Constraints on the Clumpiness of Dark Matter Halos Through Heating of Disk Galaxies

2003 ◽  
Vol 10 ◽  
pp. 95-95
Author(s):  
E. Ardi ◽  
T. Tsuchiya ◽  
A. Burkert
Keyword(s):  
Dark Matter ◽  
Disk Galaxies ◽  
Dark Matter Halos
Sign in / Sign up

Export Citation Format

Share Document