Selecting ultra-faint dwarf candidate progenitors in cosmological N-body simulations at high redshifts. Safarzadeh, M., Ji, A. P., Dooley, G. A., Frebel, A., Scannapieco, E., Gómez, F. A., & O'Shea, B. W. ArXiv e-prints, 1712:arXiv:1712.03967, December, 2017.
Selecting ultra-faint dwarf candidate progenitors in cosmological N-body simulations at high redshifts [link]Paper  abstract   bibtex   
The smallest satellites of the Milky Way ceased forming stars during the epoch of reionization and thus provide archaeological access to galaxy formation at \$z{\textgreater}6\$. Numerical studies of these ultra-faint dwarf galaxies (UFDs) require expensive cosmological simulations with high mass resolution that are carried out down to \$z=0\$. However, if we are able to statistically identify UFD host progenitors at high redshifts with relatively high probabilities, we can avoid this high computational cost. To find such candidates, we analyze the merger trees of Milky Way type halos from the high-resolution Caterpillar suite of dark matter only simulations. Satellite UFD hosts at \$z=0\$ are identified based on four different abundance matching techniques. All the halos at high redshifts are traced forward in time in order to compute the probability of surviving as satellite UFDs today. Our results show that selecting potential UFD progenitors based solely on their mass at z=12 (8) results in a 10\textbackslash% (20\textbackslash%) chance of obtaining a surviving UFD at \$z=0\$. We find that the progenitors of surviving satellite UFDs have lower virial ratios (\${\textbackslash}eta\$), and are preferentially located at large distances from the main MW progenitor, while they show no correlation with concentration parameter. Halos with favorable locations and virial ratios are \${\textbackslash}approx 3\$ times more likely to survive as satellite UFD candidates at \$z=0.\$
@article{safarzadeh_selecting_2017,
	title = {Selecting ultra-faint dwarf candidate progenitors in cosmological {N}-body simulations at high redshifts},
	volume = {1712},
	url = {http://adsabs.harvard.edu/abs/2017arXiv171203967S},
	abstract = {The smallest satellites of the Milky Way ceased forming stars during the 
epoch of reionization and thus provide archaeological access to galaxy
formation at \$z{\textgreater}6\$. Numerical studies of these ultra-faint dwarf
galaxies (UFDs) require expensive cosmological simulations with high
mass resolution that are carried out down to \$z=0\$. However, if we are
able to statistically identify UFD host progenitors at high redshifts
with relatively high probabilities, we can avoid this high computational
cost. To find such candidates, we analyze the merger trees of Milky Way
type halos from the high-resolution Caterpillar suite of dark matter
only simulations. Satellite UFD hosts at \$z=0\$ are identified based on
four different abundance matching techniques. All the halos at high
redshifts are traced forward in time in order to compute the probability
of surviving as satellite UFDs today. Our results show that selecting
potential UFD progenitors based solely on their mass at z=12 (8) results
in a 10{\textbackslash}\% (20{\textbackslash}\%) chance of obtaining a surviving UFD at \$z=0\$. We find
that the progenitors of surviving satellite UFDs have lower virial
ratios (\${\textbackslash}eta\$), and are preferentially located at large distances from
the main MW progenitor, while they show no correlation with
concentration parameter. Halos with favorable locations and virial
ratios are \${\textbackslash}approx 3\$ times more likely to survive as satellite UFD
candidates at \$z=0.\$},
	urldate = {2018-01-10},
	journal = {ArXiv e-prints},
	author = {Safarzadeh, Mohammadtaher and Ji, Alexander P. and Dooley, Gregory A. and Frebel, Anna and Scannapieco, Evan and Gómez, Facundo A. and O'Shea, Brian W.},
	month = dec,
	year = {2017},
	keywords = {Astrophysics - Astrophysics of Galaxies},
	pages = {arXiv:1712.03967},
}

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