223 citations · 2k across the 40 of their papers we have counts for
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astro-ph2007★ 109 cited
MMT observations of new extremely metal-poor emission-line galaxies in the Sloan Digital Sky Survey
Y. I. Izotov, T. X. Thuan
We present 6.5-meter MMT spectrophotometry of 20 H II regions in 13 extremely metal-poor emission-line galaxies selected from the Data Release 5 of the Sloan Digital Sky Survey to…
astro-ph2007★ 212 cited
The primordial abundance of 4He: a self-consistent empirical analysis of systematic effects in a large sample of low-metallicity HII regions
Y. I. Izotov, T. X. Thuan, G. Stasinska
We determine the primordial helium mass fraction Yp using 93 spectra of 86 low-metallicity extragalactic HII regions. This sample constitutes the largest and most homogeneous high-…