Identikit

Joshua E. Barnes & John E. Hibbard

Identikit is a numerical method, combining test-particle and self-consistent techniques, which allows a rapid exploration of the parameter space of galactic encounters. It can be used to find the parameters required to reproduce the observed morphology and kinematics of interacting disk galaxies.

Identikit 1 model (points) matching a self-consistent N-body simulation of a galactic collision (grey scale). Each panel shows a different projection: top left shows sky-plane (X,Y), top right shows velocity-position (V, Y); bottom left shows position-velocity (X, V), bottom right shows (X, Z).		Identikit 2 model of NGC 4676. Grey-scale shows HI data (Hibbard & van Gorkom 1996), projected on (α,δ) plane (top left), (V,δ) plane (top right), and (α,V) plane (bottom left). Dark blue crosses mark galaxy centers, cyan and magenta boxes are phase-space regions, and points show model derived using these constraints. Spherical lattice (bottom right) displays functions used to select viewing direction.

• Identikit 1: A Modeling Tool for Interacting Disk Galaxies [pdf file]

  — Paper describing the Identikit 1 system and a blind test of its abilities. Published in The Astronomical Journal, 137, 3071—3090, February 2009.

• Identikit 2: An Algorithm for Reconstructing Galaxy Collisions [pdf file]

  — Paper describing the Identikit 2 algorithm. Published in the Monthly Notices of the Royal Astronomical Society, 413, 2860—2872, June 2011.

• Identikit Interface

  — Web interface to Identikit 1 allows the user to select encounter and viewing parameters, and see the results instantaneously.

• Identikit Matches

  — Random merger simulations from the Identikit 1 paper; click on individual systems to see matches.

• Identikit Parameters

  — Summary of the parameters needed to define an encounter between disk galaxies.

• Identikit 1 Software [tar file]

  — Source code and key makefiles for Identikit 1.7. Requires the Zeno software environment.

• Identikit 2 Software [tar file]

  — Source code and key makefiles for Identikit 2.1. Requires the Zeno software environment.

• Sample Data [directory]

  — A small set of data files for experimenting with the Identikit software. The file jhat12X.dat records initial spin directions of test particles, while the r124_*.dat files are individual frames from an encounter between equal-mass galaxies. After downloading these files, do
      ./idkit jhat12X.dat r124_%04x.dat incr=0x100
  to try the program.

• Identikit 1: A Modeling Tool for Interacting Disk Galaxies

  — Talk given at Academia Sinica Institute of Astronomy and Astrophysics, June 4, 2008.

• Identikit (Mk0): An N-body/Data Visualization Tool

  — John Hibbard's page describing an earlier version.

Joshua E. Barnes      (barnes at ifa.hawaii.edu) Updated: 16 May 2012 http://www.ifa.hawaii.edu/~barnes/research/identikit/index.html