tests:collision
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2026-05-06T10:26:16+00:00
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https://astrowiki.surrey.ac.uk/lib/tpl/dokuwiki/images/favicon.icotext/html2022-10-24T12:26:59+00:00Anonymous (anonymous@undisclosed.example.com)GC I
https://astrowiki.surrey.ac.uk/doku.php?id=tests:collision:gc1_archive&rev=1666614419&do=diff
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) $0.919$ $1.190$text/html2022-10-24T12:26:59+00:00Anonymous (anonymous@undisclosed.example.com)GC II
https://astrowiki.surrey.ac.uk/doku.php?id=tests:collision:gc2_archive&rev=1666614419&do=diff
GC II
Summary from the Collisional Systems working group at the Gaia Challenge 2 workshop in Heidelberg (26-31st October 2014).
Participants: Adriano Agnello, Eduardo Balbinot, Paolo Bianchini, Mark Gieles, Vincent Henault-Brunet, Arkadiusz Hypki, Rosie Shanahan, Anna Sippel, Pascal Steger, Anna Lisa Varri, Glenn van de Ven, Laura Watkins, Alice Zocchi.text/html2022-10-24T12:26:59+00:00Anonymous (anonymous@undisclosed.example.com)GC III
https://astrowiki.surrey.ac.uk/doku.php?id=tests:collision:gc3&rev=1666614419&do=diff
GC III
Active participants: Ian Claydon, Mark Gieles, Vincent Henault-Brunet, Miklos Peuten, Anna Lisa Varri, Laura Watkins, Alice Zocchi.
Goals/projects for GC III workshop
A. Method comparison (a.k.a. Challenge #4):
For this Challenge, initiated in GC III in Barcelona, we decided to compare fitting methodstext/html2022-10-24T12:26:59+00:00Anonymous (anonymous@undisclosed.example.com)GC IV
https://astrowiki.surrey.ac.uk/doku.php?id=tests:collision:gc4&rev=1666614419&do=diff
GC IV
M4 mass modelling challenge: method comparison
This is a joint project between many participants, centred around mock data from Douglas Heggie’s N-body simulation of M4. The idea is to fit the M4 mock data with various mass modelling techniques and compare the results obtained with these different methods.text/html2022-10-24T12:27:00+00:00Anonymous (anonymous@undisclosed.example.com)Mock data
https://astrowiki.surrey.ac.uk/doku.php?id=tests:collision:mock_data&rev=1666614420&do=diff
Mock data
Challenge 1: Single mass clusters, isolated and tidally limited.
Challenge 2: Multi-mass clusters, no stellar evolution
Challenge 3: Clusters in tidal fields with stellar evolution
Challenge 4: Comparison of mass modelling methods using N-body model of M4.
The definition of the stellar types (KSTAR) used in thetext/html2022-10-24T12:27:00+00:00Anonymous (anonymous@undisclosed.example.com)Ideas for additional challenges
https://astrowiki.surrey.ac.uk/doku.php?id=tests:collision:new_challenges&rev=1666614420&do=diff
Ideas for additional challenges
Weighing dark remnants using luminous stars
Explore how/if the mass function of dark remnants can be constrained from a limited set of observables, using mock data from N-body simulations. This could be part of Miklos’ project on Challenge 2. Provided that this works, we can then consider a direct application to real data (e.g. Gaia-ESO survey - some of us are members of the consortium).text/html2022-10-24T12:26:59+00:00Anonymous (anonymous@undisclosed.example.com)Tools
https://astrowiki.surrey.ac.uk/doku.php?id=tests:collision:tools&rev=1666614419&do=diff
Tools
MCMC
EMCEE (Foreman-Mackey et al.) is an affine-invariant ensemble sampler:
available from the EMCEE website or at github. There is also a paper.
Laura Watkins works with this code -- ask if you have questions.
Info on other MCMC methods coming soon.....
MultiNest