标题： 利用KCWI探索J1044+0353的化学非均质性与演化 显示英文标题

标题： Using KCWI to Explore the Chemical Inhomogeneities and Evolution of J1044+0353

摘要： J1044+0353 被认为是本地的年轻星系的类比，这些年轻星系在高红移时电离了星系际介质，因为它的低质量、低金属丰度、高比恒星形成率和强高电离发射线。 我们利用积分场光谱学，使用巴耳末发射线和吸收线当量宽度来追踪此次小星系中恒星爆发的传播，并发现在距离非常年轻的紧凑型恒星爆发（约3到4百万年）大约一kpc以东的地方存在一个后期恒星爆发群体（约15到20百万年）。 使用直接电子温度法绘制O/H丰度比图，我们发现恒星爆发区和后期恒星爆发区之间的金属丰度（1到3倍标准差）相似，但在后者内部有显著的分散（约0.3 dex）。 我们还绘制了强发射线的多普勒位移和宽度。 在比星系大几倍的尺度上，我们发现了一个平行于星系短轴的旋转速度梯度。 最陡峭的梯度（~30$\mathrm{km \ s^{-1} \ kpc^{-1}}$）似乎源自最古老的恒星群集。 我们根据双锥区域中线宽和偏斜度的增加，识别出该旋转速度梯度为侧面观察到的外流。 我们讨论了这种外流以及触发恒星爆发所需的气体流入如何影响J1044+0353的化学演化。 我们得出结论，驱动星系外流的恒星群集在空间上偏离最年轻的恒星群集，并且具有金属富集风的化学演化模型需要比均匀化学演化模型更现实的流入速率。 显示英文摘要

摘要： J1044+0353 is considered a local analog of the young galaxies that ionized the intergalactic medium at high-redshift due to its low mass, low metallicity, high specific star formation rate, and strong high-ionization emission lines. We use integral field spectroscopy to trace the propagation of the starburst across this small galaxy using Balmer emission- and absorption-line equivalent widths and find a post-starburst population (~ 15 - 20 Myr) roughly one kpc east of the much younger, compact starburst (~ 3 - 4 Myr). Using the direct electron temperature method to map the O/H abundance ratio, we find similar metallicity (1 to 3 sigma) between the starburst and post-starburst regions but with a significant dispersion of about 0.3 dex within the latter. We also map the Doppler shift and width of the strong emission lines. Over scales several times the size of the galaxy, we discover a velocity gradient parallel to the galaxy's minor axis. The steepest gradients (~ 30 $\mathrm{km \ s^{-1} \ kpc^{-1}}$) appear to emanate from the oldest stellar association. We identify the velocity gradient as an outflow viewed edge-on based on the increased line width and skew in a biconical region. We discuss how this outflow and the gas inflow necessary to trigger the starburst affect the chemical evolution of J1044+0353. We conclude that the stellar associations driving the galactic outflow are spatially offset from the youngest association, and a chemical evolution model with a metal-enriched wind requires a more realistic inflow rate than a homogeneous chemical evolution model.