A population of eruptive variable protostars in VVV
A population of eruptive variable protostars in VVV
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DOI：
10.1093/mnras/stw2801
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发表时间：
2016-02
影响因子：
4.8
通讯作者：
C. C. Peña-C.;P. Lucas;D. Minniti;R. Kurtev;W. Stimson;C. N. Molina;J. Borissova;N. Kumar;M. Thompson;T.Gledhill;R. Terzi;D. Froebrich;A. C. O. Garatti
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文献类型：
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作者：
C. C. Peña-C.;P. Lucas;D. Minniti;R. Kurtev;W. Stimson;C. N. Molina;J. Borissova;N. Kumar;M. Thompson;T.Gledhill;R. Terzi;D. Froebrich;A. C. O. Garatti
我们发现了816颗高振幅红外变星（？Ks > 1 mag）在Via Lactea（VVV）巡天中被VISTA变星覆盖的银河中面119 deg 2。几乎所有的都是新发现的，大约50？per？年轻恒星（YSO）这进一步证明了YSO是银河平面中最常见的高振幅红外变星。在2010-2014年可能的YSO的时间序列中，我们发现，除了短时间尺度（100天）和162个短期变量外，变异的幅度向年轻的进化类（I类和平谱源）增加。爆发性YSO和衰减器往往具有最高的振幅，爆发性系统具有最红的光谱能量分布（SED）。后续的光谱学在一个配套文件验证了高吸积率的喷发系统。两个时期的彩色数据不利于可变消光。这些发现增加了喷发变量YSO的数量至少5倍，大多数处于比已知的FUor和EXor类型更早的演化阶段。我们发现，喷发的可变性至少是一个数量级更常见的第一类YSO比第二类YSO。典型的爆发持续时间为1-4年，介于EXOR和FUOR之间。在4年的时间跨度内，第一类YSO中有3- 6%发生了这种情况。
We present the discovery of 816 high-amplitude infrared variable stars (?Ks > 1 mag) in 119 deg2 of the Galactic mid-plane covered by the VISTA Variables in the Via Lactea (VVV) survey. Almost all are new discoveries and about 50?per?cent are young stellar objects (YSOs). This provides further evidence that YSOs are the commonest high-amplitude infrared variable stars in the Galactic plane. In the 2010–2014 time series of likely YSOs, we find that the amplitude of variability increases towards younger evolutionary classes (class I and flat-spectrum sources) except on short time-scales ( 100 d) and 162 short-term variables. Eruptive YSOs and faders tend to have the highest amplitudes and eruptive systems have the reddest spectral energy distribution (SEDs). Follow-up spectroscopy in a companion paper verifies high accretion rates in the eruptive systems. Variable extinction is disfavoured by the two epochs of colour data. These discoveries increase the number of eruptive variable YSOs by a factor of at least 5, most being at earlier stages of evolution than the known FUor and EXor types. We find that eruptive variability is at least an order of magnitude more common in class I YSOs than class II YSOs. Typical outburst durations are 1–4 yr, between those of EXors and FUors. They occur in 3–6 per cent of class I YSOs over a 4 yr time span.