Outflow forces in intermediate mass star formation
Outflow forces in intermediate mass star formation
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DOI：
10.1051/0004-6361/201424725
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发表时间：
2015-07
影响因子：
6.5
通讯作者：
T. V. Kempen;M. Hogerheijde;E. Dishoeck;L. Kristensen;L. Kristensen;A. Belloche;P. Klaassen;S. Leurini;I. Jose-Garcia;A. Aykutalp;Y. Choi;Y. Choi;A. Endo;W. Frieswijk;D. Harsono;A. Karska;E. Koumpia;E. Koumpia;N. Marel;Z. Nagy;Z. Nagy;J. Perez-Beaupuits;C. Risacher;C. Risacher;R. Weeren;R. Weeren;F. Wyrowski;U. Yıldız;U. Yıldız;R. Güsten;W. Boland;A. Baryshev;A. Baryshev
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文献类型：
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作者：
T. V. Kempen;M. Hogerheijde;E. Dishoeck;L. Kristensen;L. Kristensen;A. Belloche;P. Klaassen;S. Leurini;I. Jose-Garcia;A. Aykutalp;Y. Choi;Y. Choi;A. Endo;W. Frieswijk;D. Harsono;A. Karska;E. Koumpia;E. Koumpia;N. Marel;Z. Nagy;Z. Nagy;J. Perez-Beaupuits;C. Risacher;C. Risacher;R. Weeren;R. Weeren;F. Wyrowski;U. Yıldız;U. Yıldız;R. Güsten;W. Boland;A. Baryshev;A. Baryshev
上下文。中等质量的原恒星在低质量和高质量恒星形成理论之间架起了一座桥梁。通过中等质量原恒星的流出力与总光度（而不是单个光度）的明显相关性，可以利用这些源产生的分子流出物来确定碎片化和多样性对原恒星演化的影响。目标。本文的目的是从六个中等质量原恒星区域的流出中推导出流出力，并验证早期工作中看到的总光度与流出力之间的明显相关性，并消除不同方法引起的不确定性。方法。通过比较APEX获得的CO 6‐5观测值与非lte辐射传输模型预测值，得出了分子流出气体的光学深度、温度和密度。随后计算了流出力、动态时标和动力学光度。结果。导出了所有源的流出参数，包括力。所有流动的温度都超过50 K，这与最近的低质量结果一致。然而，与其他研究的比较并不能证实早期关于中质量原恒星的研究得出的结论，该结论假设碎裂增强了集群中质量恒星形成过程中的流出力。与经典的流出力与光度关系相比，任何增强都可以归因于使用了更高的激发线和方法的改进；它们与使用类似技术的低质量原恒星的结果一致。结论。碎片对流出的作用是理解星团形成以及低质量和高质量恒星形成之间联系的重要因素。但是，为了取得必要的进展，需要提供关于100个非盟的空间尺度的详细资料，包括所有个别成员。
Context. Protostars of intermediate mass provide a bridge between theories of low- and high-mass star formation. Molecular outflows emerging from such sources can be used to determine the influence of fragmentation and multiplicity on protostellar evolution through the apparent correlation of outflow forces of intermediate mass protostars with the total luminosity instead of the individual luminosity. Aims. The aim of this paper is to derive outflow forces from outflows of six intermediate mass protostellar regions and validate the apparent correlation between total luminosity and outflow force seen in earlier work, as well as remove uncertainties caused by di erent methodology. Methods. By comparing CO 6‐5 observations obtained with APEX with non-LTE radiative transfer model predictions, optical depths, temperatures, densities of the gas of the molecular outflows are derived. Outflow forces, dynamical timescales and kinetic luminosities are subsequently calculated. Results. Outflow parameters, including the forces, were derived for all sources. Temperatures in excess of 50 K were found for all flows, in line with recent low-mass results. However, comparison with other studies could not corroborate conclusions from earlier work on intermediate mass protostars which hypothesized that fragmentation enhances outflow forces in clustered intermediate mass star formation. Any enhancement in comparison with the classical relation between outflow force and luminosity can be attributed the use of a higher excitation line and improvement in methods; They are in line with results from low-mass protostars using similar techniques. Conclusions. The role of fragmentation on outflows is an important ingredient to understand clustered star formation and the link between low and high-mass star formation. However, detailed information on spatial scales of a few 100 AU, covering all individual members is needed to make the necessary progress.