arXiv 1407.05952014-07-02astro-ph.SRastro-ph.EP

利用虚拟天文台进行年轻女士物理参数测定的方法比较

Physical parameter determinations of young Ms. Taking advantage of the Virtual Observatory to compare methodologies

A. Bayo, C. Rodrigo, D. Barrado, F. Allard

备注：: 4 pages, 3 figures, submitted to the proceedings of "Gaia and the unseen - the brown dwarf question", Torino, 24-26 March 2014, to be published in Memorie della Societa' Astronomica Italiana (SAIt), eds Ricky Smart, David Barrado, Jackie Faherty

摘要：

从事恒星物理学研究的天文学家为推进他们的研究而采取的第一步是确定研究对象最常见/相关的物理参数（有效温度，辐射热光度，表面重力等）。不同的方法存在取决于数据的性质，对象的内在属性等一个常见的方法是比较观测数据与理论模型通过一些模拟器，将在合成数据中留下相同的印记比观测数据进行，并看看什么样的参数集再现观测最好。即使在这种情况下，根据天文学家拥有的数据类型，方法也会略有变化。在参数公布后，社会往往会引用、赞扬和批评它们，有时很少关注可能的差异是来自理论模型、数据本身还是分析中使用的方法。在这项工作中，我们执行简单的，但有趣的，练习的有效温度比较通过SED和更详细的光谱拟合（相同的网格模型），一个样本的著名的和特征的年轻的M-型对象成员不同的恒星形成区域，并显示如何在高达350 K的温度差异可以预期只是从所使用的方法/数据的差异。另一方面，我们展示了对于较冷的物体，即使拟合的复杂性增加（例如引入差分消光），这些差异也会较小。为了进行这项工作，我们大大受益于虚拟天文台提供的框架。

英文摘要：

One of the very first steps astronomers working in stellar physics perform to advance in their studies, is to determine the most common/relevant physical parameters of the objects of study (effective temperature, bolometric luminosity, surface gravity, etc.). Different methodologies exist depending on the nature of the data, intrinsic properties of the objects, etc. One common approach is to compare the observational data with theoretical models passed through some simulator that will leave in the synthetic data the same imprint than the observational data carries, and see what set of parameters reproduce the observations best. Even in this case, depending on the kind of data the astronomer has, the methodology changes slightly. After parameters are published, the community tend to quote, praise and criticize them, sometimes paying little attention on whether the possible discrepancies come from the theoretical models, the data themselves or just the methodology used in the analysis. In this work we perform the simple, yet interesting, exercise of comparing the effective temperatures obtained via SED and more detailed spectral fittings (to the same grid of models), of a sample of well known and characterized young M-type objects members to different star forming regions and show how differences in temperature of up to 350 K can be expected just from the difference in methodology/data used. On the other hand we show how these differences are smaller for colder objects even when the complexity of the fit increases like for example introducing differential extinction. To perform this exercise we benefit greatly from the framework offered by the Virtual Observatory.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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