Observational signatures of outbursting protostars - II. Exploring a wide range of eruptive protostars
Observational signatures of outbursting protostars - II. Exploring a wide range of eruptive protostars
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爆发原恒星的观测特征 - II。
DOI：
10.1093/mnras/stz1570
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发表时间：
2019
影响因子：
4.8
通讯作者：
Lee Jeong-Eun
中科院分区：
文献类型：
--
作者：
MacFarlane Benjamin;Stamatellos Dimitris;Johnstone Doug;Herczeg Gregory;Baek Giseon;Chen Huei-Ru Vivien;Kang Sung-Ju;Lee Jeong-Eun
由于气体吸积率的变化，年轻恒星表现出变异性，这种影响在它们形成的早期阶段应该是相当显著的。由于原恒星嵌入了它们诞生的云层中，这种可变性可能只能通过长波长观测来推断。我们对流体力学模拟中形成的年轻恒星对象(YSO)进行辐射传输模拟，改变其结构和光度性质，以估计其通量的长波、亚毫米和毫米变化。我们发现，由于爆发事件导致的通量增加取决于原恒星的结构，并且在亚毫米波长比在毫米波长更显著；例如，年轻原恒星光度增加40倍会导致250μm时通量增加10倍，而1.3 mm时仅增加2.5倍。我们发现，星际辐射场冲淡了通量的增加，但如果分辨率允许监测YSO的内部区域，这种影响是可以避免的，那里的加热主要是由于原恒星辐射。我们还证实，爆发的原恒星的测热温度和光度可能会导致对其演化阶段的错误分类。
Young stars exhibit variability due to changes in the gas accretion rate onto them, an effect that should be quite significant in the early stages of their formation. As protostars are embedded within their natal cloud, this variability may only be inferred through long wavelength observations. We perform radiative transfer simulations of young stellar objects (YSOs) formed in hydrodynamical simulations, varying the structure and luminosity properties in order to estimate the long-wavelength, sub-mm and mm, variations of their flux. We find that the flux increase due to an outburst event depends on the protostellar structure and is more prominent at sub-mm wavelengths than at mm wavelengths; e.g. a factor of 40 increase in the luminosity of the young protostar leads to a flux increase of a factor of 10 at 250μm but only a factor of 2.5 at 1.3 mm. We find that the interstellar radiation field dilutes the flux increase but that this effect may be avoided if resolution permits the monitoring of the inner regions of a YSO, where the heating is primarily due to protostellar radiation. We also confirm that the bolometric temperature and luminosity of outbursting protostars may result in an incorrect classification of their evolutionary stage.