Constraining the top-light initial mass function in the extended ultraviolet disk of M83
Constraining the top-light initial mass function in the extended ultraviolet disk of M83
复制标题
约束M83扩展紫外盘中的顶光初始质量函数
DOI：
10.1051/0004-6361/202347729
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发表时间：
2023
影响因子：
6.5
通讯作者：
Rautio R
中科院分区：
文献类型：
--
作者：
Rautio R
初始质量函数（IMF）的普适性或非普适性对于从恒星星族的光度特性确定星星形成速率和星星形成历史具有重要意义在M83外盘的低密度环境中（顶光），并限制其中IMF的形状。方法使用档案星系演化探测器（GALEX）远紫外（FUV）和近紫外（NUV）数据和新的深OmegaCAM窄带Hα成像，我们构建了一个目录的FUV选择的对象在外盘的M 83。我们对星表中的Hα亮星系团和在FUV−NUV中呈蓝色的星系团进行了计数，测量了星系团之间的最大通量比FH α/fλ FUV，并测量了星表中的总通量比FHα/fλ FUV。然后，我们将这些测量结果与标准Salpeter IMF，截断IMF和陡峭IMF的恒星人口合成模型的预测进行了比较。我们还研究了不同的假设内部灭绝对我们的results.ResultsWe的效果是不能够重现我们的意见与模型使用标准的萨尔彼得IMF或截断IMF。只有当假设外盘恒星团的平均内部消光为0.10 <AV<0.15时，具有陡峭IMF（α> 3.1）的模型才能同时再现观测到的星系团计数、观测到的最大FH α/fλFUV和观测到的ΣFHα/ΣfλFUV。结论我们的结果支持非普适IMF，它在低密度环境中的大质量恒星中是缺乏的。
ContextThe universality or non-universality of the initial mass function (IMF) has significant implications for determining star formation rates and star formation histories from photometric properties of stellar populations.AimsWe reexamine whether the IMF is deficient in high-mass stars (top-light) in the low-density environment of the outer disk of M 83 and constrain the shape of the IMF therein.MethodsUsing archival Galaxy Evolution Explorer (GALEX) far ultraviolet (FUV) and near ultraviolet (NUV) data and new deep OmegaCAM narrowband Hαimaging, we constructed a catalog of FUV-selected objects in the outer disk of M 83. We counted Hα-bright clusters and clusters that are blue in FUV−NUV in the catalog, measured the maximum flux ratioFHα/fλFUVamong the clusters, and measured the total flux ratio ΣFHα/ΣfλFUVover the catalog. We then compared these measurements to predictions from stellar population synthesis models made with a standard Salpeter IMF, truncated IMFs, and steep IMFs. We also investigated the effect of varying the assumed internal extinction on our results.ResultsWe are not able to reproduce our observations with models using the standard Salpeter IMF or the truncated IMFs. It is only when assuming an average internal extinction of 0.10 <AV< 0.15 in the outer disk stellar clusters that models with steep IMFs (α> 3.1) simultaneously reproduce the observed cluster counts, the maximum observedFHα/fλFUV, and the observed ΣFHα/ΣfλFUV.ConclusionsOur results support a non-universal IMF that is deficient in high-mass stars in low-density environments.