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tests:collision:gc1_archive

GC I

Challenge 1: Equal mass clusters in a tidal field

All Stars 1000 stars
Cluster Method $M$$r_{\rm c}$$r_{\rm h}$$r_{\rm J}$ $M$$r_{\rm c}$$r_{\rm h}$$r_{\rm J}$
1 Isotropic King (linear dens) $0.919$ $1.190$
Isotropic King (log dens) $0.046$ $1.61$
Anisotropic Michie King $0.027$ $1.55$
$f_\nu$ $1.082$ $1.134$
2 Isotropic King (linear dens) $0.875$ $1.322$
Isotropic King (log dens) $0.04$ $1.752$
Anisotropic Michie King $0.026$ $1.618$
$f_\nu$ $1.023$ $1.314$
3 Isotropic King (linear dens) $0.227$ $6.839$
Isotropic King (log dens) $0.28$ $7.655$
Anisotropic Michie King
$f_\nu$ $0.259$ $8.225$
Cluster Plots
1 Isotropic King vs $f_\nu$
Anisotropic Michie King
2 Isotropic King vs $f_\nu$
Anisotropic Michie King
3 Isotropic King vs $f_\nu$
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:

$m$ $X$ $Y$ $Z$ $V_x$ $V_y$ $V_z$ $\log T_{EFF}$ $M_{bol}$ 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:

Cluster Mass Radii rms velocities
$r_{\rm h}$(3D,M)$r_{\rm h}$(2D,L)$r_{\rm h}$(2D,M)$r_{\rm h}$(2D,N)$v_{\rm rms}$$v_{\rm rms}$(Giants)
[$M_\odot$] [pc] [pc] [pc] [pc] [km/s][km/s]
1 $3.34\times10^4$ 9.73 3.33 7.27 10.0 2.39 2.52
2 $3.33\times10^4$ 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 $M$$r_{\rm h}$$R_{\rm h}$$M$$r_{\rm h}$$R_{\rm h}$$M$$r_{\rm h}$$R_{\rm h}$
1 isotropic King $3.17*10^4$ $11.76$ $8.67$ $3.03*10^4$ $9.06$ $6.66$ $3.07*10^4$ $8.63$ $6.39$
Multi-mass King
$f_\nu$ $3.80*10^4$ $12.88$ $9.66$ $3.54*10^4$ $9.00$ $6.73$ $3.08*10^4$ $3.31$ $2.48$
Parametric Jeans
Discrete Jeans
2 Isotropic King $3.07*10^4$ $14.27$ $10.55$ $2.72*10^4$ $11.69$ $8.32$ $2.93*10^4$ $11.13$ $8.19$
Multi-mass King
$f_\nu$ $3.71*10^4$ $14.66$ $11.03$ $3.66*10^4$ $11.07$ $8.26$ $3.30*10^4$ $6.08$ $4.50$
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. $f_\nu$
  2. Multi-mass King
  3. Discrete “Jeans like” modelling
  4. DF fitting (Mark W?)

Results:

Using all stars:

All Stars 1000 stars
Cluster Snapshot Method $M$$r_{\rm c}$$r_{\rm h}$$r_{\rm J}$ $M$$r_{\rm c}$$r_{\rm h}$$r_{\rm J}$
1 1 Isotropic King
1 Multimass Michie King
1 $f_\nu$
1 Discrete modelling
1 2 Isotropic King
2 Multimass Michie King
2 $f_\nu$
2 Discrete modelling
1 3 Isotropic King
3 Multimass Michie King
3 $f_\nu$
3 Discrete modelling
1 4 Isotropic King
4 Multimass Michie King $2.118$ $11.353$
4 $f_\nu$
4 Discrete modelling
2 1 Isotropic King
1 Multimass Michie King
1 $f_\nu$
1 Discrete modelling
2 2 Isotropic King
2 Multimass Michie King
2 $f_\nu$
2 Discrete modelling
2 3 Isotropic King
3 Multimass Michie King
3 $f_\nu$
3 Discrete modelling
2 4 Isotropic King
4 Multimass Michie King
4 $f_\nu$
4 Discrete modelling

Plots

Cluster Plots
1 1 Isotropic King vs $f_\nu$
1 Multimass Michie King
1 Discrete modelling
1 2 Isotropic King vs $f_\nu$
2 Multimass Michie King
2 Discrete modelling
1 3 Isotropic King vs $f_\nu$
3 Multimass Michie King
3 Discrete modelling
1 4 Isotropic King vs $f_\nu$
4 Multimass Michie King
4 Discrete modelling
2 1 Isotropic King vs $f_\nu$
1 Multimass Michie King
1 Discrete modelling
2 2 Isotropic King vs $f_\nu$
2 Multimass Michie King
2 Discrete modelling
2 3 Isotropic King vs $f_\nu$
3 Multimass Michie King
3 Discrete modelling
2 4 Isotropic King vs $f_\nu$
4 Multimass Michie King
4 Discrete modelling

Results:

Velocity dispersion for different mass species: the multi-mass King models assume that the product $m\sigma_K^2$= constant. The parameters $\sigma_K$ is not exactly the velocity dispersion.

tests/collision/gc1_archive.txt · Last modified: 2015/09/01 10:33 by v.henault-brunet