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tests:collision:gc1_archive

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GCI

Challenge 1: Equal mass clusters in a tidal field

All Stars 1000 stars
Cluster Method
1 Isotropic King (linear dens)
Isotropic King (log dens)
Anisotropic Michie King
2 Isotropic King (linear dens)
Isotropic King (log dens)
Anisotropic Michie King
3 Isotropic King (linear dens)
Isotropic King (log dens)
Anisotropic Michie King
 Cluster Plots 1 Isotropic King vs Anisotropic Michie King 2 Isotropic King vs Anisotropic Michie King 3 Isotropic King vs Anisotropic Michie King

Challenge 2: Isolated models with stellar evolution

Active participants: Alice Zocchi, Antonio Sollima, Matt Walker, , Laura Watkins, Glenn van de Ven, Pascal Steger?

How important is the effect of mass segregation?

1. How correct is the assumption of energy equipartition (i.e. multi-mass King models)?
2. How different are the fits when considering: 1.) all stars, 2.) only visible stars
3. Is it better to consider luminosity weighted profiles, or number density profiles?
4. How much can we do with 2 velocity components instead of 1 (i.e. with Gaia data)?

Description of the models:

(Based on simulations ran by Mark Gieles, not published)
Here we consider 2 clusters:

1. IC: Cored gamma/eta model, N = 1e5, Kroupa (2001) mass function between 0.1-100 Msun.
2. No primordial binaries, no central black hole, no tidal.
3. Stellar evolution and mass-loss according to Hurley et al. (2000, 2002)
4. Two values for the metallicity of the stars: [Fe/H] = -2.0 and 0.0 (solar)

Below are 2 snapshots at an age of roughly 12 Gyr. The columns are:

KSTAR
[Msun] [PC] [km s-1] [K] [MAG]

KSTAR is the stellar type and can be between 0 and 22 and the meanings are given below in the Appendix.

Cluster properties:

(3D,M)(2D,L)(2D,M)(2D,N)(Giants)
[] [pc] [pc] [pc] [pc] [km/s][km/s]
1 9.73 3.33 7.27 10.0 2.39 2.52
2 10.9 4.71 8.20 11.3 2.30 2.67

Density distribution for cluster 2:

(PRELIMINARY) RESULTS:

All Stars ND All Stars Mass All Stars Lum
Cluster Method
1 isotropic King
Multi-mass King
Parametric Jeans
Discrete Jeans
2 Isotropic King
Multi-mass King
Parametric Jeans
Discrete Jeans

Challenge 3: Clusters in tidal fields with stellar evolution

(Simulations ran and kindly made available by Holger Baumgardt)

Here we consider 2 clusters which are slightly more realistic:

1. IC: King (1966) W_0 = 5 model, N = 131072, Kroupa (2001) mass function between 0.1-15 Msun (no black-holes).
2. No primordial binaries, no central black hole, circular orbit in logarithmic halo with V = 220 km/s.
3. Z = 0.001
4. Stellar evolution and mass-loss according to Hurley et al. (2000, 2002)
5. Two Galactocentric radii: 8.5 kpc and 15 kpc.

Below are 2 snapshots at an age of roughly 10 Myr, 100 Myr, 1Gyr and 12 Gyr. The columns are the same as in Challenge 2.

1. w05_n131k_rg8.5_feh-0.0_t10.gz UPDATED! Thursday August 22
2. w05_n131k_rg8.5_feh-0.0_t100.gz UPDATED! Thursday August 22
3. w05_n131k_rg8.5_feh-0.0_t1000.gz UPDATED! Thursday August 22
4. w05-n131k_rg15_feh-0.0.t10.gz NEW! Tuesday August 20
5. w05-n131k_rg15_feh-0.0.t100.gz NEW! Tuesday August 20
6. w05-n131k_rg15_feh-0.0.t1000.gz NEW! Tuesday August 20

Questions are the same as in Challenge 2, and in addition:

1. Is the presence of the tidal field affecting the velocity anisotropy in the outer parts?
2. Can the mass segregation be reproduced by multi-mass King models?

Example of the velocity dispersion difference of different mass components:

Different models to fit:

1. Multi-mass King
2. Discrete “Jeans like” modelling
3. DF fitting (Mark W?)

Results:

Using all stars:

All Stars 1000 stars
Cluster Snapshot Method
1 1 Isotropic King
1 Multimass Michie King
1
1 Discrete modelling
1 2 Isotropic King
2 Multimass Michie King
2
2 Discrete modelling
1 3 Isotropic King
3 Multimass Michie King
3
3 Discrete modelling
1 4 Isotropic King
4 Multimass Michie King
4
4 Discrete modelling
2 1 Isotropic King
1 Multimass Michie King
1
1 Discrete modelling
2 2 Isotropic King
2 Multimass Michie King
2
2 Discrete modelling
2 3 Isotropic King
3 Multimass Michie King
3
3 Discrete modelling
2 4 Isotropic King
4 Multimass Michie King
4
4 Discrete modelling

Plots

 Cluster Plots 1 1 Isotropic King vs 1 Multimass Michie King 1 Discrete modelling 1 2 Isotropic King vs 2 Multimass Michie King 2 Discrete modelling 1 3 Isotropic King vs 3 Multimass Michie King 3 Discrete modelling 1 4 Isotropic King vs 4 Multimass Michie King 4 Discrete modelling 2 1 Isotropic King vs 1 Multimass Michie King 1 Discrete modelling 2 2 Isotropic King vs 2 Multimass Michie King 2 Discrete modelling 2 3 Isotropic King vs 3 Multimass Michie King 3 Discrete modelling 2 4 Isotropic King vs 4 Multimass Michie King 4 Discrete modelling

Results:

Velocity dispersion for different mass species: the multi-mass King models assume that the product = constant. The parameters is not exactly the velocity dispersion.