THE RMS SURVEY: THE LUMINOSITY FUNCTIONS AND TIMESCALES OF MASSIVE YOUNG STELLAR OBJECTS AND COMPACT H ii REGIONS
THE RMS SURVEY: THE LUMINOSITY FUNCTIONS AND TIMESCALES OF MASSIVE YOUNG STELLAR OBJECTS AND COMPACT H ii REGIONS
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RMS 调查：大质量年轻恒星和致密 H ii 区域的光度函数和时间尺度
DOI：
10.1088/2041-8205/730/2/l33
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
J. Stead
中科院分区：
文献类型：
--
作者：
J. Mottram;M. Hoare;B. Davies;S. Lumsden;R. Oudmaijer;J. Urquhart;T. Moore;H. Cooper;J. Stead
我们提出了一个确定的光度函数的大规模的年轻恒星对象（MYSO）和紧凑的（C）H II区域内的银河系使用的大，精心挑选的样本，这些来源确定的红色MSX源调查。MYSO的光度函数单调下降，因此只有很少的区域L <$105 L返，而CH ii区域的探测值高达106 L返。这些阶段的寿命也计算作为一个功能的光度与当地的主序OB星的光度函数的比较。这表明MYSO相的持续时间从4×105年（104 L）到107 ×104年（105 L）不等，而CH ii区相的持续时间约为3×105年，相当于激发星星主序星寿命的13%-10%。在104升和105升之间的MYSO是巨大的，但没有显示无线电连续谱或近红外H i复合线发射指示H ii区域，这与由于高的持续或最近的吸积率而膨胀一致。当超过105 L时，MYSO的相寿命变得与主序星的开尔文-亥姆霍兹时间尺度相当，此时中央的星星可以迅速收缩到主序星上，即使仍在吸积，并进入CH ii区域，从而解释了为什么很少观察到高亮度的MYSO。
We present a determination of the luminosity functions of massive young stellar objects (MYSOs) and compact (C) H ii regions within the Milky Way using the large, well-selected sample of these sources identified by the Red MSX Source survey. The MYSO luminosity function decreases monotonically such that there are few with L≳105 L☉, while the CH ii regions are detected up to ∼106 L☉. The lifetimes of these phases are also calculated as a function of luminosity by comparison with the luminosity function for local main-sequence OB stars. These indicate that the MYSO phase has a duration ranging from 4×105 yr for 104 L☉ to ∼7×104 yr at 105 L☉, while the CH ii region phase lasts of order 3×105 yr or ∼3%–10% of the exciting star's main-sequence lifetime. MYSOs between 104 L☉ and ∼105 L☉ are massive but do not display the radio continuum or near-IR H i recombination line emission indicative of an H ii region, consistent with being swollen due to high ongoing or recent accretion rates. Above ∼105 L☉ the MYSO phase lifetime becomes comparable to the main-sequence Kelvin–Helmholtz timescale, at which point the central star can rapidly contract onto the main sequence even if still accreting, and ionize a CH ii region, thus explaining why few highly luminous MYSOs are observed.
红色 MSX 源巡天：年轻大质量恒星的辐射热通量和光度分布
影响因子：
6.5
作者：
Mottram J
通讯作者：
Mottram J