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J/ApJ/689/919      Dynamical evolution of globular clusters      (Prieto+, 2008)

Dynamical evolution of globular clusters in hierarchical cosmology. Prieto J.L., Gnedin O.Y. <Astrophys. J., 689, 919-935 (2008)> =2008ApJ...689..919P (SIMBAD/NED BibCode)
ADC_Keywords: Models, evolutionary ; Clusters, globular Keywords: galaxies: formation - galaxies: kinematics and dynamics - galaxies: star clusters - globular clusters: general Abstract: We test the hypothesis that metal-poor globular clusters form within disk galaxies at redshifts z>3. We calculate the orbits of model clusters in the time-variable gravitational potential of a Milky Way-sized galaxy, using the outputs of a cosmological N-body simulation. We find that at present the orbits are isotropic in the inner 50kpc of the Galaxy and preferentially radial at larger distances. All clusters located outside 10kpc from the center formed in satellite galaxies, some of which are now tidally disrupted and some of which survive as dwarf galaxies. Mergers of the progenitors lead to a spheroidal spatial distribution of model clusters, although it is more extended than that of Galactic metal-poor clusters and has a somewhat shallower power-law slope of the number density profile, γ∼2.7. The combination of two-body relaxation, tidal shocks, and stellar evolution drives the evolution of the cluster mass function from an initial power law to a peaked distribution, in agreement with observations. However, not all initial conditions and not all evolution scenarios are consistent with the observed mass function of the Galactic globular clusters. We find that our best-fitting models require the average cluster density, M/R3h, to be constant initially for clusters of all mass and to remain constant with time. However, these models do not explain the observed decrease of the mean density with galactocentric distance. Both synchronous formation of all clusters at a single epoch (z=4) and continuous formation over a span of 1.6Gyr (between z=9 and 3) are consistent with the data. For both formation scenarios, we provide online catalogs of the main physical properties of model clusters. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 82 97 *Catalog of clusters in model Sb-ii table4.dat 82 87 *Catalog of clusters in model Cb-ii
Notes on table3.dat and table4.dat: Models as follows: -------------------------------------------------------------------------- Model Rh(0) Rh(t) γ <e> fM fN logMpeak σ PK-S -------------------------------------------------------------------------- Sb-ii M(0)1/3 M(t)1/3 2.7 0.53 0.46 0.16 5.47 0.52 4E-10 Cb-ii M(0)1/3 M(t)1/3 2.7 0.52 0.15 0.04 5.51 0.71 0.063 -------------------------------------------------------------------------- See section 2.3 for further details.
Byte-by-byte Description of file: table[34].dat
Bytes Format Units Label Explanations
1- 3 F3.1 --- zf Redshift of formation 5- 8 F4.2 [Msun] logM Present cluster mass 10- 13 F4.2 [Msun] logMi Initial cluster mass 15- 18 F4.1 pc Rh Present half-mass radius 20- 23 F4.1 pc Rhi Initial half-mass radius 25- 29 F5.1 kpc r Present distance to center of main galaxy 31- 35 F5.1 kpc ri Initial distance to center of main galaxy 37- 40 F4.1 [Msun] logMh Host galaxy mass at time of cluster formation 42- 47 F6.1 kpc x x-coordinate of cluster with respect to main galaxy 49- 54 F6.1 kpc y y-coordinate of cluster with respect to main galaxy 56- 61 F6.1 kpc z z-coordinate of cluster with respect to main galaxy 63- 68 F6.1 km/s vx x-velocity of cluster 70- 75 F6.1 km/s vy y-velocity of cluster 77- 82 F6.1 km/s vz z-velocity of cluster
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 21-Jan-2011
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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