论文标题
用光学测定限制热黑体参数时的错误
Errors When Constraining Hot Blackbody Parameters with Optical Photometry
论文作者
论文摘要
在许多天体物理研究中，仅使用光学数据来测量比几个10^4K的黑体参数要热得多。但是，此过程容易出现大误差，因为在这些温度下，光带主要是对光谱的雷利吉恩尾尾进行采样。在这里，我们通过模拟不同的黑体，在具有逼真的测量误差的各个频段中对它们进行采样来量化这些误差，并使用两种不同的方法和两个不同的先验将它们重新安装到黑体中。我们发现，仅使用光学数据时，对数均匀的先验比均匀的先验更好。尽管如此，〜35,000k以上的黑体的测量温度可能是〜10,000K是错误的，只有大于〜50,000k的黑色温度，只能获得下限。从仅光学黑体拟合中估计的降压光度可能是3-5的因素可能是错误的。当添加基于空间的紫外线数据时，这些误差会大大缩小。对于当没有可用的数据时，我们提供了可导致各种测量温度的真实温度分布的图和表。在将热黑体与光学数据拟合时，将这些分布视为系统的不确定性很重要。
Measuring blackbody parameters for objects hotter than a few 10^4K with optical data alone is common in many astrophysical studies. However this process is prone to large errors because at those temperatures the optical bands are mostly sampling the Rayleigh-Jeans tail of the spectrum. Here we quantify these errors by simulating different blackbodies, sampling them in various bands with realistic measurement errors, and re-fitting them to blackbodies using two different methods and two different priors. We find that when using only optical data, log-uniform priors perform better than uniform priors. Still, measured temperatures of blackbodies above ~35,000K can be wrong by ~10,000K, and only lower limits can be obtained for temperatures of blackbodies hotter than ~50,000K. Bolometric luminosities estimated from optical-only blackbody fits can be wrong by factors of 3-5. When adding space-based ultraviolet data, these errors shrink significantly. For when such data are not available, we provide plots and tables of the distributions of true temperatures that can result in various measured temperatures. It is important to take these distributions into account as systematic uncertainties when fitting hot blackbodies with optical data alone.
