A grid of chemical evolution models as a tool to interpret spiral and irregular galaxies data
A grid of chemical evolution models as a tool to interpret spiral and irregular galaxies data
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DOI：
10.1111/j.1365-2966.2005.08782.x
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发表时间：
2005-01
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影响因子：
--
通讯作者：
M. MollaA.I.Diaz
中科院分区：
文献类型：
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作者：
M. MollaA.I.Diaz
我们提出了多相化学演化模型的概括，该模型适用于具有不同质量和演化速率的广泛理论星系。这组广义模型是使用 Persic、Salucci & Steel (1996) 的所谓通用旋转曲线计算的，以计算 44 个理论原星系的径向质量分布。这种分布是一个基本输入，除了它本身对星系演化的影响之外，它还定义了特征坍缩时间尺度或气体流入盘上的速率。对于总质量的每一个径向分布，我们为分子云和恒星形成效率采用了 10 组介于 0 和 1 之间的值，与其概率性质相对应。因此，我们根据这些效率集和旋转速度构建了一个双参数模型网格，其结果原则上对任何螺旋或不规则星系都有效。模型结果提供了盘和晕不同区域沿银心距离的时间演化，通过气体（原子和分子）和恒星质量、恒星形成速率和 14 种元素的化学丰度来测量，总共 440 个模型。该网格可用于估计给定星系的演化，该星系仅提供当前时间信息，例如元素丰度、气体密度和/或恒星形成的径向分布，这些是化学演化模型的常见观测约束。
We present a generalization of the multiphase chemical evolution model applied to a wide set of theoretical galaxies with di ff erent masses and evolutionary rates. This general-ized set of models has been computed using the so-called Universal Rotation Curve from Persic, Salucci & Steel (1996) to calculate the radial mass distribution of 44 theoretical protogalaxies. This distribution is a fundamental input which, besides its own e ff ect on the galaxy evolution, defines the characteristic collapse time-scale or gas infall rate onto the disc. We have adopted 10 sets of values, between 0 and 1, for the molecular cloud and star formation e ffi ciencies, as corresponding to their probability nature, for each one of the radial distributions of total mass. Thus, we have constructed a bi-parametric grid of models, depending on those e ffi ciency sets and on the rotation velocity, whose results are valid in principle for any spiral or irregular galaxy. The model results provide the time evolution of di ff erent regions of the disc and the halo along galactocentric distance, measured by the gas (atomic and molecular) and stellar masses, the star formation rate and chemical abundances of 14 elements, for a total of 440 models. This grid may be used to estimate the evolution of a given galaxy for which only present time information – such as radial distributions of elemental abundances, gas densities and / or star formation, which are the usual observational constraints of chemical evolution models – is available.