EXTREME EMISSION-LINE GALAXIES IN CANDELS: BROADBAND-SELECTED, STARBURSTING DWARF GALAXIES AT z > 1

van der Wel, A.; Straughn, A. N.; Rix, H. -W.; Finkelstein, S. L.; Koekemoer, A. M.; Weiner, B. J.; Wuyts, S.; Bell, E. F.; Faber, S. M.; Trump, J. R.; Koo, D. C.; Ferguson, H. C.; Scarlata, C.; Hathi, N. P.; Dunlop, J. S.; Newman, J. A.; Dickinson, M.; Jahnke, K.; Salmon, B. W.; de Mello, D. F.; Kocevski, D. D.; Lai, K.; Grogin, N. A.; Rodney, S. A.; Guo, Yicheng; McGrath, E. J.; Lee, K. -S.; Barro, G.; Huang, K. -H.; Riess, A. G.; Ashby, M. L. N.; Willner, S. P.
2011
ASTROPHYSICAL JOURNAL
DOI
10.1088/0004-637X/742/2/111
We identify an abundant population of extreme emission-line galaxies (EELGs) at redshift z similar to 1.7 in the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey imaging from Hubble Space Telescope/Wide Field Camera 3 (HST/WFC3). Sixty-nine EELG candidates are selected by the large contribution of exceptionally bright emission lines to their near-infrared broadband magnitudes. Supported by spectroscopic confirmation of strong [OIII] emission lines-with rest-frame equivalent widths similar to 1000 angstrom-in the four candidates that have HST/WFC3 grism observations, we conclude that these objects are galaxies with similar to 10(8) M-circle dot in stellar mass, undergoing an enormous starburst phase with M-*/(M) over dot(*) of only similar to 15 Myr. These bursts may cause outflows that are strong enough to produce cored dark matter profiles in low-mass galaxies. The individual star formation rates and the comoving number density (3.7 x 10(-4) Mpc(-3)) can produce in similar to 4 Gyr much of the stellar mass density that is presently contained in 10(8)-10(9) M-circle dot dwarf galaxies. Therefore, our observations provide a strong indication that many or even most of the stars in present-day dwarf galaxies formed in strong, short-lived bursts, mostly at z > 1.