Dust Emission and Molecular Depletion in L1498
Dust Emission and Molecular Depletion in L1498
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DOI：
10.1086/311695
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发表时间：
1998-09
期刊：
影响因子：
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通讯作者：
K. Willacy;William D. Langer;T. Velusamy
中科院分区：
文献类型：
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作者：
K. Willacy;William D. Langer;T. Velusamy
我们给出了对致密核L1498的100和200μm等光电子能谱观测。我们通过使用ΔI200=I200-I100/Θ绘制了中心地核的地图，其中ΔI200是冷尘埃排放的量度，Θ=I100/I200在外层区域。在缺乏气体示踪剂的情况下，尘埃连续排放提供了有关化学耗竭和冷芯性质的信息。前人对L1498的观测表明，CS和CCS的发射位于NH3核之外。ΔI200中的峰位于先前观察到的NH3峰附近。与C18O发射的高空间分辨率观测结果比较表明，ΔI200的最大值与核心中心的C18O发射的下降相吻合。我们估计，该地区C18O的损耗系数至少为8，而且可能更大。如此高的耗尽率对气粒化学和原恒星核的研究具有重要意义。
We present 100 and 200 μm ISOPHOT observations of the dense core L1498. We have mapped the central core by using ΔI200=I200-I100/Θ, where ΔI200 is a measure of the emission from the cold dust and Θ=I100/I200 in the outer regions. The dust continuum emission provides information about the chemical depletion and the properties of cold cores where there is a lack of gas tracers. Previous observations of L1498 show that the emission from CS and CCS lies outside of the NH3 core. The peak in ΔI200 lies close to the previously observed NH3 peak. A comparison with high spatial resolution observations of C18O emission shows that the ΔI200 maximum coincides with a dip in the C18O emission at the core center. We estimate that the depletion factor for C18O in this region is at least 8 and is likely to be much larger. Such high depletion has significant implications for studies of gas-grain chemistry and protostellar cores.