论文标题
MIMAS的降压键反照率和热惯性图
Bolometric Bond Albedo and Thermal Inertia Maps of Mimas
论文作者
论文摘要
我们使用来自Cassini复合材料红外光谱仪CIR的数据来绘制MIMAS的表面温度及其热物理特性。这为Howett等人的工作提供了巨大的改进。 （2011年），其中仅在MIMAS上的两个区域（一个内部，另一个在异常区域外）确定值。我们使用CIRS的焦平面3（fp3，600至1100 cm-1）的所有空间分辨扫描，这在很大程度上是白天的观察结果，但确实包括一个夜间。所得的温度图证实了Mimas先前发现的热异常区域的存在和位置。尽管我们注意到，在Mimas的领先和抗湿半球上表面覆盖不完整，但没有发现其他热异常区域。热惯性图证实，异常区域的热惯性明显高于其周围环境：98 +/- 42 J M-2 K-1 S-1/2在异常内部，而外面的34 +/- 34 +/- 32 J M-2 K-1 S-1/2。异常区域内外的反照率在其不确定性内同意：内部0.45 +/- 0.08，而异常外0.41 +/- 0.07。有趣的是，反照率在异常区域内显得更明亮，鉴于该区域在某些UV波长下确实更明亮，这可能并不奇怪（0.338微米，请参见Schenk等，2011）。但是，应谨慎对待该结果，因为如前所述，当考虑其不确定性时，这两个区域的反照率是相同的。在此确定的这些热惯性和反照率值与Howett等人发现的热惯性值一致。 （2011年），确定异常内部的热惯性为66 +/- 23 J M-2 K-1 S/2，外部小于16 J M-2 K-1 S/2小于16 J M-2 K-1 S/2，反照率从0.49到0.70。
We use data from Cassini's Composite Infrared Spectrometer CIRS to map Mimas' surface temperatures and its thermophysical properties. This provides a dramatic improvement on the work in Howett et al. (2011), where the values were determined at only two regions on Mimas (one inside, and another outside of the anomalous region). We use all spatially-resolved scans made by CIRS' focal plane 3 (FP3, 600 to 1100 cm-1) of Mimas' surface, which are largely daytime observations but do include one nighttime one. The resulting temperature maps confirm the presence and location of Mimas' previously discovered thermally anomalous region. No other thermally anomalous regions were discovered, although we note that the surface coverage is incomplete on Mimas' leading and anti-Saturn hemisphere. The thermal inertia map confirms that the anomalous region has a notably higher thermal inertia than its surroundings: 98 +/- 42 J m-2 K-1 s-1/2 inside of the anomaly, compared to 34 +/- 32 J m-2 K-1 s-1/2 outside. The albedo inside and outside of the anomalous region agrees within their uncertainty: 0.45+/-0.08 inside compared to 0.41 +/- 0.07 outside the anomaly. Interestingly the albedo appears brighter inside the anomaly region, which may not be surprising given this region does appear brighter at some UV wavelengths (0.338 microns, see Schenk et al., 2011). However, this result should be treated with caution because, as previously stated, statistically the albedo of these two regions is the same when their uncertainties are considered. These thermal inertia and albedo values determined here are consistent with those found by Howett et al. (2011), who determined the thermal inertia inside the anomaly to be 66 +/- 23 J m-2 K-1 s-1/2 and less than 16 J m-2 K-1 s-1/2 outside, with albedos that varied from 0.49 to 0.70.
