Subhalo Merger Trees
Subhalo merger trees have been created for the Illustris simulations using the SubLink code (Rodriguez-Gomez et al. 2015). This code was featured in the Sussing Merger Trees comparison project (Srisawat et al. 2013), with favorable results. Its official website can be found on BitBucket.The merger trees can be accessed in two different "modes:"
- Database mode: Quick and simple Python implementation (readtreeHDF5.py). This is enough for most purposes.
- Linked-list mode: A more powerful approach, but it can only be implemented efficiently in C++ due to memory limitations. Feel free to contact me to obtain the C++ code for doing this.
Python usage example
The following example inside an IPython interactive session imports the readtreeHDF5.py Python script and then reads the stellar mass history of a subhalo:
In [1]: import readtreeHDF5
In [2]: treedir = '/n/ghernquist/vrodrigu/MergerTrees/output/Subhalos/Illustris/L75n1820FP'
In [3]: tree = readtreeHDF5.TreeDB(treedir)
In [4]: snapnum = 135; subfind_id = 0
In [5]: branch = tree.get_main_branch(snapnum, subfind_id, keysel=['SubhaloMassType'])
In [6]: branch.SubhaloMassType[:,4]
Out[6]:
array([ 2.33393616e+02, 2.36594543e+02, 2.31190689e+02,
2.28168961e+02, 2.25794037e+02, 2.25409058e+02,
2.18946014e+02, 2.17864563e+02, 2.11786011e+02,
2.10338608e+02, 2.05883530e+02, 2.05351608e+02,
2.06869431e+02, 2.02407578e+02, 2.03302048e+02,
1.95617722e+02, 1.90876785e+02, 1.90310043e+02,
1.89997925e+02, 1.90455124e+02, 1.85761642e+02,
1.86246506e+02, 1.85166718e+02, 1.85115265e+02,
1.85175873e+02, 1.84385437e+02, 1.85189850e+02,
1.82988495e+02, 1.82881836e+02, 1.80221802e+02,
1.81669479e+02, 1.84483536e+02, 1.76489914e+02,
1.73764557e+02, 1.72029312e+02, 1.67181274e+02,
1.65797485e+02, 1.52316513e+02, 1.41573288e+02,
1.43456469e+01, 1.11532280e+02, 1.02701935e+02,
1.01446526e+02, 1.01805817e+02, 1.03256004e+02,
8.91545715e+01, 7.94949036e+01, 7.89413147e+01,
7.83848801e+01, 7.76846542e+01, 8.11160507e+01,
6.58123627e+01, 6.66783981e+01, 5.75135651e+01,
5.16523438e+01, 4.66071243e+01, 4.31353264e+01,
3.82537384e+01, 3.63100281e+01, 3.69525604e+01,
3.31881142e+01, 3.28055305e+01, 3.14911003e+01,
2.92666035e+01, 2.56113510e+01, 2.16436481e+01,
1.92428932e+01, 1.65285492e+01, 1.54052744e+01,
1.39484034e+01, 1.19876518e+01, 1.05805073e+01,
9.63882637e+00, 8.26193523e+00, 6.77282429e+00,
6.34307098e+00, 6.18107319e+00, 5.72066116e+00,
5.20444489e+00, 4.04215097e+00, 2.27483058e+00,
1.07108188e+00, 8.07452261e-01, 5.13630271e-01,
4.51999515e-01, 3.17362517e-01, 2.31387287e-01,
1.89680010e-01, 1.57841980e-01, 1.18739337e-01,
5.85642345e-02, 2.95610856e-02, 1.85859483e-02,
1.19343642e-02, 6.79354137e-03, 3.85794253e-03,
2.25251797e-03, 1.84609054e-03, 1.59247383e-03,
1.31974125e-03, 6.94582006e-04, 7.08998181e-04,
6.46255910e-04, 4.01783938e-04, 2.08377212e-04,
9.75056755e-05, 1.05029045e-04, 0.00000000e+00,
0.00000000e+00, 0.00000000e+00, 0.00000000e+00], dtype=float32)
| Last updated: October 20, 2017 | Picture credit: Greg Snyder |