Roadmap for the Project¶
Get initial galaxy data¶
- Choose 2 galaxies to follow their history
- massive elliptical
- beautiful spiral
- Find their merger history
- Get sub_halo_id number for each galaxy for each of the 135 snapshots
- Assume that the merger history continues along the line of largest merger participant
- Decide what data will be interesting
- Star formation rate
- Filter magnitudes
- Particle positions
- Particle sizes too (if available)
- Mass of particle
- Total mass
- Dark matter mass
- Gas mass
- Star mass
- Decide which particles in the sub-halo “belong” to the galaxy at the centre of the sub-halo
- Do we decide on a star-mass density limit? Or combined star+gas mass density limit
- Do we use a luminosity (density) limit?
Pull data from illustris database¶
- Write function to get the above mentioned data for a galaxy at a particular snapshot
- Save the data somewhere in a coherent naming scheme
- Decide, based on query/download speed whether to download data again every
- time the scripts are run, or whether to save the data in cache and load from
disk (i.e.
astropy.download_file(url=..., cache=True)
)
Make “ideal” mock 2D maps/images of galaxy¶
“Ideal” maps/images mean what the galaxy would look like before a telescope was used to observe it. This could mean we display the stellar mass of the galaxy in an image, or actually use the intensity of a galaxy in a given filter band (UVIKgriz). We also want to be able to view the galaxy from any angle
Function to display an integrated 2D “column-density”-style map of the galaxy for any set of rotation angles
Function to automaticaly determine the semi-major and -minor axes of the sub-halo ellipsoid
- Function to rotate particle positions to the following orientations:
- Face on - view of largest and 2nd largest axes
- Edge on - view of largest and smallest axes
- End on - view of smallest and 2nd smallest axes
This could be done with a principle component analysis
- Function to make maps of the following of each galaxy for each of the three main orientations:
- Flux intensity in each of the UVRIgriz filters
- Star formation rate
- Stellar mass
- Gas + stellar mass
- Dark matter
- Function to generate these maps on-the-fly and return a fits image at a giving spatial angular resolution, given a snapshot distance (i.e. lookback time)
- See Ned Wright’s cosmological calculator for angular distances vs redshift
- Combine this funtionality into a python package
- Write the appropriate tests, and documentation
Time for the fun stuff:
- Generate these maps for each of the snapshots of a galaxy
- Create GIFs of the evolution of the galaxy over cosmic time
- Create these maps for a fixed viewing angle
- Create these maps oriented along one of the principle axes
- Plot integrated parameters over the whole galaxies vs cosmic time (snapshot and lookback time)
- Each of the parameters listed in 4.