Extinction techniques and impact on dust property determination
Extinction techniques and impact on dust property determination
复制标题
消光技术及其对粉尘性质测定的影响
DOI：
10.1111/j.1365-2966.2006.10436.x
复制
发表时间：
2006
影响因子：
4.8
通讯作者：
D. Observatory
中科院分区：
文献类型：
--
作者：
D. Froebrich;C. Studies;D. Observatory
近红外（NIR）消光幂律指数（I²）及其不确定性来自三种不同的技术，基于星星计数，颜色过剩和它们的组合。我们已经将这些方法应用于2微米全天巡天（2MASS）数据，以确定小型云IC 1396 W的I²和NIR消光图。结合星星计数和颜色过量，是确定I²的最可靠方法。它被发现，使用正确的I²地图转换颜色过剩值到消光是云的柱密度剖面分析的基础。我们描述了如何人工测光数据，银河系的恒星人口合成模型的基础上，可以用来估计不确定性，并获得系统的消光方法在这里提出的影响。我们发现，所有的颜色过剩的消光测定方法受到小，但系统的偏移，这并不影响星星计数技术。这些偏移的发生是因为透过星云看到的恒星并不代表与无闪烁控制场中的恒星相同的星群。© 2006 RAS.
The near-infrared (NIR) extinction power-law index (I²) and its uncertainty is derived from three different techniques based on star counts, colour excess and a combination of them. We have applied these methods to Two Micron All Sky Survey (2MASS) data to determine maps of I² and NIR extinction of the small cloud IC 1396 W. The combination of star counts and colour excess results in the most reliable method to determine I². It is found that the use of the correct I² map to transform colour excess values into extinction is fundamental for column density profile analysis of clouds. We describe how artificial photometric data, based on the model of stellar population synthesis of the Galaxy, can be used to estimate uncertainties and derive systematic effects of the extinction methods presented here. We find that all colour excess based extinction determination methods are subject to small but systematic offsets, which do not affect the star counting technique. These offsets occur since stars seen through a cloud do not represent the same population as stars in an extinction-free control field. © 2006 RAS.