Extreme infrared variables from UKIDSS - I. A concentration in star-forming regions
Extreme infrared variables from UKIDSS - I. A concentration in star-forming regions
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UKIDSS 的极红外变量 - I. 恒星形成区域的集中
DOI：
10.1093/mnras/stu063
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发表时间：
2014
影响因子：
4.8
通讯作者：
Contreras Peña C
中科院分区：
文献类型：
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作者：
Contreras Peña C
我们提出了第一次在银河平面上对高振幅近红外变异性的全景搜索的初步结果。我们分析了UKIDSS银河面巡天第五次和第七次数据发布中广泛分离的两时代波段光度。我们发现了45颗ΔK >1等的恒星，包括两颗以前已知的OH/IR恒星和一颗新星。尽管中间平面尚未包含在数据集中，但我们发现我们的样本中的大多数（66%）位于已知的恒星形成区域（SFRs）内，其中两个较大的集中在Serpens OB2 association（11颗恒星）和Cygnus-X complex（12颗恒星）中。SFRs中的源显示了支持归类为年轻恒星天体（yso）的光谱能量分布。这表明yso在低光度的高振幅红外变星中占主导地位，因此可能在整个高振幅变星中占主导地位。对DR5样本的光谱跟踪显示，至少有四颗恒星具有明显的爆发前主序变元特征，其中两颗是深嵌的。我们的研究结果支持了最近的喷发变动性概念，该概念包括不同时间尺度和光度的爆发事件连续体，但由涉及不稳定吸积的类似物理机制触发。同时，我们发现了似乎是最多变的经典be星之一。
We present initial results of the first panoramic search for high-amplitude near-infrared variability in the Galactic plane. We analyse the widely separated two-epochK-band photometry in the fifth and seventh data releases of the UKIDSS Galactic plane survey. We find 45 stars with ΔK> 1 mag, including two previously known OH/IR stars and a Nova. Even though the mid-plane is not yet included in the data set, we find the majority (66 per cent) of our sample to be within known star-forming regions (SFRs), with two large concentrations in the Serpens OB2 association (11 stars) and the Cygnus-X complex (12 stars). Sources in SFRs show spectral energy distributions that support classification as young stellar objects (YSOs). This indicates that YSOs dominate the Galactic population of high-amplitude infrared variable stars at low luminosities and therefore likely dominate the total high-amplitude population. Spectroscopic follow up of the DR5 sample shows at least four stars with clear characteristics of eruptive pre-main-sequence variables, two of which are deeply embedded. Our results support the recent concept of eruptive variability comprising a continuum of outburst events with different time-scales and luminosities, but triggered by a similar physical mechanism involving unsteady accretion. Also, we find what appears to be one of the most variable classical Be stars.