We present new constraints on the star formation histories of six ultra-faint
dwarf galaxies: Bootes I, Canes Venatici II, Coma Berenices, Hercules, Leo IV,
and Ursa Major I. Our analysis employs a combination of high-precision
photometry obtained with the Advanced Camera for Surveys on the Hubble Space
Telescope, medium-resolution spectroscopy obtained with the DEep Imaging
Multi-Object Spectrograph on the W.M. Keck Observatory, and updated
Victoria-Regina isochrones tailored to the abundance patterns appropriate for
these galaxies. The data for five of these Milky Way satellites are best fit by
a star formation history where at least 75% of the stars formed by z~10 (13.3
Gyr ago). All of the galaxies are consistent with 80% of the stars forming by
z~6 (12.8 Gyr ago) and 100% of the stars forming by z~3 (11.6 Gyr ago). The
similarly ancient populations of these galaxies support the hypothesis that
star formation in the smallest dark matter sub-halos was suppressed by a global
outside influence, such as the reionization of the universe.
Description
[1410.0681] The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization Era
%0 Generic
%1 brown2014quenching
%A Brown, Thomas M.
%A Tumlinson, Jason
%A Geha, Marla
%A Simon, Joshua D.
%A Vargas, Luis C.
%A VandenBerg, Don A.
%A Kirby, Evan N.
%A Kalirai, Jason S.
%A Avila, Roberto J.
%A Gennaro, Mario
%A Ferguson, Henry C.
%A Munoz, Ricardo R.
%A Guhathakurta, Puragra
%A Renzini, Alvio
%D 2014
%K dwarf galaxies quenching reionization
%T The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization Era
%U http://arxiv.org/abs/1410.0681
%X We present new constraints on the star formation histories of six ultra-faint
dwarf galaxies: Bootes I, Canes Venatici II, Coma Berenices, Hercules, Leo IV,
and Ursa Major I. Our analysis employs a combination of high-precision
photometry obtained with the Advanced Camera for Surveys on the Hubble Space
Telescope, medium-resolution spectroscopy obtained with the DEep Imaging
Multi-Object Spectrograph on the W.M. Keck Observatory, and updated
Victoria-Regina isochrones tailored to the abundance patterns appropriate for
these galaxies. The data for five of these Milky Way satellites are best fit by
a star formation history where at least 75% of the stars formed by z~10 (13.3
Gyr ago). All of the galaxies are consistent with 80% of the stars forming by
z~6 (12.8 Gyr ago) and 100% of the stars forming by z~3 (11.6 Gyr ago). The
similarly ancient populations of these galaxies support the hypothesis that
star formation in the smallest dark matter sub-halos was suppressed by a global
outside influence, such as the reionization of the universe.
@misc{brown2014quenching,
abstract = {We present new constraints on the star formation histories of six ultra-faint
dwarf galaxies: Bootes I, Canes Venatici II, Coma Berenices, Hercules, Leo IV,
and Ursa Major I. Our analysis employs a combination of high-precision
photometry obtained with the Advanced Camera for Surveys on the Hubble Space
Telescope, medium-resolution spectroscopy obtained with the DEep Imaging
Multi-Object Spectrograph on the W.M. Keck Observatory, and updated
Victoria-Regina isochrones tailored to the abundance patterns appropriate for
these galaxies. The data for five of these Milky Way satellites are best fit by
a star formation history where at least 75% of the stars formed by z~10 (13.3
Gyr ago). All of the galaxies are consistent with 80% of the stars forming by
z~6 (12.8 Gyr ago) and 100% of the stars forming by z~3 (11.6 Gyr ago). The
similarly ancient populations of these galaxies support the hypothesis that
star formation in the smallest dark matter sub-halos was suppressed by a global
outside influence, such as the reionization of the universe.},
added-at = {2014-10-06T09:39:55.000+0200},
author = {Brown, Thomas M. and Tumlinson, Jason and Geha, Marla and Simon, Joshua D. and Vargas, Luis C. and VandenBerg, Don A. and Kirby, Evan N. and Kalirai, Jason S. and Avila, Roberto J. and Gennaro, Mario and Ferguson, Henry C. and Munoz, Ricardo R. and Guhathakurta, Puragra and Renzini, Alvio},
biburl = {https://www.bibsonomy.org/bibtex/23133ebeae48af478f2a7968c002e9019/miki},
description = {[1410.0681] The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization Era},
interhash = {612362176b6f6a3c9c4b5d6a95616f68},
intrahash = {3133ebeae48af478f2a7968c002e9019},
keywords = {dwarf galaxies quenching reionization},
note = {cite arxiv:1410.0681Comment: Accepted for publication in The Astrophysical Journal. 13 pages, 5 color and 3 grayscale figures, 2 tables},
timestamp = {2014-10-06T09:39:55.000+0200},
title = {The Quenching of the Ultra-Faint Dwarf Galaxies in the Reionization Era},
url = {http://arxiv.org/abs/1410.0681},
year = 2014
}