Constraints on the Global Mass-to-Light Ratios and on the Extent of Dark Matter Halos in Globular Clusters and Dwarf Spheroidals

1996 ◽  
Vol 461 (1) ◽  
Author(s):  
Ben Moore
2005 ◽  
Vol 619 (1) ◽  
pp. 258-269 ◽  
Author(s):  
Sergey Mashchenko ◽  
Alison Sills

2011 ◽  
Vol 741 (2) ◽  
pp. 72 ◽  
Author(s):  
Charlie Conroy ◽  
Abraham Loeb ◽  
David N. Spergel

2006 ◽  
Vol 640 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Takayuki R. Saitoh ◽  
Jin Koda ◽  
Takashi Okamoto ◽  
Keiichi Wada ◽  
Asao Habe

Author(s):  
Nelson Caldwell ◽  
Jay Strader ◽  
David J. Sand ◽  
Beth Willman ◽  
Anil C. Seth

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.


2008 ◽  
Vol 672 (2) ◽  
pp. 904-913 ◽  
Author(s):  
Jorge Penarrubia ◽  
Alan W. McConnachie ◽  
Julio F. Navarro

2021 ◽  
Vol 922 (2) ◽  
pp. 193
Author(s):  
Anna T. P. Schauer ◽  
Volker Bromm ◽  
Michael Boylan-Kolchin ◽  
Simon C. O. Glover ◽  
Ralf S. Klessen

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.


2008 ◽  
Vol 687 (2) ◽  
pp. 1460-1460 ◽  
Author(s):  
Jorge Peñarrubia ◽  
Alan W. McConnachie ◽  
Julio F. Navarro

2005 ◽  
Vol 619 (1) ◽  
pp. 243-257 ◽  
Author(s):  
Sergey Mashchenko ◽  
Alison Sills

2015 ◽  
Vol 12 (S316) ◽  
pp. 336-337
Author(s):  
Joowon Lee ◽  
Jihye Shin ◽  
Sungsoo S. Kim

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.


2002 ◽  
Vol 207 ◽  
pp. 593-598
Author(s):  
Jennifer M. Lotz ◽  
Bryan W. Miller ◽  
Henry C. Ferguson ◽  
Massimo Stiavelli ◽  
Rosemary Telford

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.


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