The building up of the disk galaxy M 33 and the evolution of the metallicity gradient
The building up of the disk galaxy M 33 and the evolution of the metallicity gradient
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DOI：
10.1051/0004-6361:20077215
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发表时间：
2007-04
影响因子：
6.5
通讯作者：
L. Magrini;E. Corbelli;D. Galli
中科院分区：
文献类型：
--
作者：
L. Magrini;E. Corbelli;D. Galli
语境。盘星系中金属丰度径向梯度的演化及其与盘形成的关系尚不清楚。星系化学演化的理论模型对金属丰度梯度的时间演化做出了相反的预测。目标。为了测试化学演化模型并追踪低光度盘状星系的恒星形成和吸积历史，我们重点研究本星系群 M 33。方法。我们分析了行星状星云、Hii 区域和年轻恒星中的 O/ Ha 和 S/H 丰度，以及 M 33 老恒星群中已知的 [Fe/H] 丰度。通过理论模型，我们跟踪 M 33 盘中气体（在云中扩散和浓缩）、恒星和化学丰度的时间演化，假设星系正在从外部吸积气体 水库。结果。我们的模型能够重现 M 33 中气体和恒星分布的可用观测限制，并预测几种化学丰度的时间演化。特别是，我们发现一个模型，其特征是气体以 u 的速率连续流入圆盘上。
Context. The evolution of radial gradients of metallicity in disk galaxies and its relation to disk formation are not well understood. Theoretical models of galactic chemical evolution make contrasting predictions about the time evolution of metallicity gradients. Aims. To test chemical evolution models and trace the star formation and accretion history of low luminosity disk galaxies we focus on the Local Group galaxy M 33. Methods. We analyze O/ Ha nd S/H abundances in planetary nebulae, Hii regions, and young stars, together with known [Fe/H] abundances in the old stellar population of M 33. With a theoretical model, we follow the time evolution of gas (diffuse and condensed in clouds), stars, and chemical abundances in the disk of M 33, assuming that the galaxy is accreting gas from an external reservoir. Results. Our model is able to reproduce the available observational constraints on the distribution of gas and stars in M 33 and to predict the time evolution of several chemical abundances. In particular, we find that a model characterized by a continuous infall of gas on the disk, at a rate of u