ATLASGAL - physical parameters of dust clumps associated with 6.7 GHz methanol masers
ATLASGAL - physical parameters of dust clumps associated with 6.7 GHz methanol masers
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ATLASGAL - 与 6.7 GHz 甲醇微波激射器相关的尘埃团块的物理参数
DOI：
10.1093/mnras/stz2691
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发表时间：
2019
影响因子：
4.8
通讯作者：
Billington S
中科院分区：
文献类型：
--
作者：
Billington S
我们已经建造了最大的样本尘埃相关的II类6.7 GHz甲醇脉泽尚未获得。甲醇多光束（MMB）巡天的新测量结果与870 APEX望远镜大面积星系巡天（ATLASGAL）和850 JCMT平面巡天（JPS）相结合。加上以前的两项研究，我们现在已经确定了958个甲醇脉泽的宿主团块，覆盖了MMB目录的大约99%，并将已知的尘埃相关脉泽样本增加了30%以上。我们调查之间的相关性的物理性质的团块和脉泽使用的距离和光度从文献中得出。甲醇脉泽所在的团块比一般团块明显更紧凑，并且具有更高的体积密度。我们确定了中质量和高质量恒星有效形成的最小体积密度阈值n（H2）≥ 104 cm-3。我们发现6.7 GHz甲醇脉泽与演化过程的一个独特部分（Lbol/Mfwhm比值在100.6和102.2之间）相关，并且具有明确的开启点和终止点。我们估计嵌入天体的质量下限为≥6 M Ω，甲醇脉泽级的统计寿命为1.33 × 104年。这表明，甲醇脉泽确实是高质量星星形成的可靠示踪剂，并表明该标记跟踪的演化时期是相对较快的。
We have constructed the largest sample of dust-associated class II 6.7 GHz methanol masers yet obtained. New measurements from the Methanol Multibeam (MMB) survey were combined with the 870APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) and the 850JCMT Plane Survey (JPS). Together with two previous studies we have now identified the host clumps for 958 methanol masers across the Galactic Plane, covering approximately 99 per cent of the MMB catalogue and increasing the known sample of dust-associated masers by over 30 per cent. We investigate correlations between the physical properties of the clumps and masers using distances and luminosities drawn from the literature. Clumps hosting methanol masers are significantly more compact and have higher volume densities than the general population of clumps. We determine a minimum volume density threshold ofn(H2) ≥ 104cm−3for the efficient formation of intermediate- and high-mass stars. We find 6.7 GHz methanol masers are associated with a distinct part of the evolutionary process (Lbol/Mfwhmratios of between 100.6and 102.2) and have well-defined turning on and termination points. We estimate the lower limit for the mass of embedded objects to be ≥6 M⊙and the statistical lifetime of the methanol maser stage to be ∼3.3 × 104yr. This suggests that methanol masers are indeed reliable tracers of high-mass star formation, and indicates that the evolutionary period traced by this marker is relatively rapid.