L1495 revisited: a ppmap view of a star-forming filament
L1495 revisited: a ppmap view of a star-forming filament
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重温 L1495：恒星形成细丝的 ppmmap 视图
DOI：
10.1093/mnras/stz2234
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发表时间：
2019
影响因子：
4.8
通讯作者：
Howard A
中科院分区：
文献类型：
--
作者：
Howard A
我们利用贝叶斯拟合程序分析了金牛座L1495恒星形成区主丝的herschelandscuba -2尘埃连续体观测结果。(i)如果我们沿着灯丝的整个长度构造一个平均剖面，它具有fwhm，但与先前估计的接近是巧合。（ii）如果我们分析细丝的局部小截面，柱密度剖面很接近等温圆柱体流体静力平衡预测的形式。（iii） ppmap能够区分在不同温度下发射的尘埃，从而区分丝的温暖外层和脊柱附近的冷内层，导致表面密度的显著降低，因此线密度μ。如果我们采用临界线密度在气体动力学温度下的标准值，则灯丝平均是跨临界的，其中μ > μ crit0 μ crit0的局部截面倾向于靠近恒星前核心。（iv） ppmap1区分不同类型尘埃的能力，即以不同的发射率指数β值为特征的尘埃，表明细丝内尘埃的发射率指数β > 1.5，低于细丝外尘埃的发射率指数β > 1.7，表明细丝内的物理条件影响了尘埃性质的变化。
We have analysed theHerschelandSCUBA-2dust continuum observations of the main filament in the Taurus L1495 star-forming region, using the Bayesian fitting procedureppmap. (i) If we construct an average profile along the whole length of the filament, it has FWHMbut the closeness to previous estimates is coincidental. (ii) If we analyse small local sections of the filament, the column-density profile approximates well to the form predicted for hydrostatic equilibrium of an isothermal cylinder. (iii) The ability ofppmapto distinguish dust emitting at different temperatures, and thereby to discriminate between the warm outer layers of the filament and the cold inner layers near the spine, leads to a significant reduction in the surface-density,, and hence in the line-density, μ. If we adopt the canonical value for the critical line-density at a gas-kinetic temperature of,, the filament is on average trans-critical, withlocal sections where μ > μCRITtend to lie close to prestellar cores. (iv) The ability ofppmapto distinguish different types of dust, i.e. dust characterized by different values of the emissivity index, β, reveals that the dust in the filament has a lower emissivity index, β ≲ 1.5, than the dust outside the filament, β ≳ 1.7, implying that the physical conditions in the filament have effected a change in the properties of the dust.