tests:collision:gc1_archive
Table of Contents
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?
- How correct is the assumption of energy equipartition (i.e. multi-mass King models)?
- How different are the fits when considering: 1.) all stars, 2.) only visible stars
- Is it better to consider luminosity weighted profiles, or number density profiles?
- 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:
- IC: Cored gamma/eta model, N = 1e5, Kroupa (2001) mass function between 0.1-100 Msun.
- No primordial binaries, no central black hole, no tidal.
- Stellar evolution and mass-loss according to Hurley et al. (2000, 2002)
- 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:
- IC: King (1966) W_0 = 5 model, N = 131072, Kroupa (2001) mass function between 0.1-15 Msun (no black-holes).
- No primordial binaries, no central black hole, circular orbit in logarithmic halo with V = 220 km/s.
- Z = 0.001
- Stellar evolution and mass-loss according to Hurley et al. (2000, 2002)
- 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.
- w05_n131k_rg8.5_feh-0.0_t10.gz UPDATED! Thursday August 22
- w05_n131k_rg8.5_feh-0.0_t100.gz UPDATED! Thursday August 22
- w05_n131k_rg8.5_feh-0.0_t1000.gz UPDATED! Thursday August 22
- w05-n131k_rg15_feh-0.0.t10.gz NEW! Tuesday August 20
- w05-n131k_rg15_feh-0.0.t100.gz NEW! Tuesday August 20
- w05-n131k_rg15_feh-0.0.t1000.gz NEW! Tuesday August 20
Questions are the same as in Challenge 2, and in addition:
- Is the presence of the tidal field affecting the velocity anisotropy in the outer parts?
- 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:
- $f_\nu$
- Multi-mass King
- Discrete “Jeans like” modelling
- 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: 2022/10/24 12:26 by 127.0.0.1