Young Galaxies

Thuan，Trinh Xuan 96-16863 Thuan博士将继续与来自Unkraine和俄罗斯的科学家合作，研究附近的星系，这些星系是极度缺乏金属的蓝色紧凑星系。 第一个研究目标是获得一个高精度的原始氦丰度的候选蓝色紧凑星系的样本测量。 原始He丰度是制约标准大爆炸核合成理论和蓝致密矮星系化学演化模型的最有希望的途径之一。 第二个目标是研究年轻的蓝色致密星系周围的扩展HI包层。 这些是原始中性氢星系际云的很好的候选者，将对其进行研究，以帮助理解为什么星星的形成在这些包层中受到如此长时间的阻碍。

Thuan, Trinh Xuan 96-16863 Dr. Thuan will continue a collaboration with scientists from Unkraine and Russia to study nearby galaxies which are extremely metal- deficient blue compact galaxies. The first research goal is to obtain a high precision measure of the primordial helium abundance for a sample of candidate blue compact galaxies. The primordial He abundance constitutes one of the most promising ways to constrain the standard Big Bang nucleosynthesis theory and the chemical evolution models of blue compact dwarf galaxies. The second goal is to study the extended HI envelopes around young blue compact galaxies. These are good candidates for being primordial neutral hydrogen intergalactic clouds, which will be studied to help understand why star formation has been stunted for so long in these envelopes.