Short time-scale variability in the Faint Sky Variability Survey
Short time-scale variability in the Faint Sky Variability Survey
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微弱天空变率巡天中的短时间尺度变率
DOI：
10.1111/j.1365-2966.2006.10792.x
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
U. Chile
中科院分区：
文献类型：
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作者：
L. Morales;P. Groot;T. Augusteijn;G. Nelemans;P. Vreeswijk;E. Nijmegen;Nordic Optical Telescope;E. Observatory;U. Chile
我们给出了从24分钟到几十天的时间尺度上对微弱天空变率调查中点源的V波段变率分析。我们发现，在V=24以下的点源中，约有1%是变量。我们讨论了每个场的变率检测概率取决于现场采样、变率的幅度和时间尺度。颜色和可变性信息的组合使我们能够探索不同光谱类型的可变源的比例。我们发现，大约50%的变量具有小于6h的变化时间尺度，变量的总数以主序列源为主。具有光谱类型的变量沿主序列的分布相当恒定，1%的源是可变的，除了在主序列的蓝色端，在光谱类型F0和F5之间，其中可变源的比例增加到约2%。对于较蓝的震源，在主序列上方，这一百分比增加到约3.5。我们发现，抽样和观察次数的结合使我们能够确定所发现变量的最多40%的变异性、时间尺度和幅度。在调查中发现的短时间尺度变量总数中，约有三分之一在B频段或/和I频段都没有检测到。它们显示出与在所有三个波段中检测到的变量相似的变异性-时间尺度分布。
We present the V-band variability analysis of the point sources in the Faint Sky Variability Survey on time-scales from 24 min to tens of days. We find that about one per cent of the point sources down to V = 24 are variables. We discuss the variability-detection probabilities for each field depending on field sampling, amplitude and time-scale of the variability. The combination of colour and variability information allows us to explore the fraction of variable sources for different spectral types. We find that about 50 per cent of the variables show variability time-scales shorter than 6 h. The total number of variables is dominated by main-sequence sources. The distribution of variables with spectral type is fairly constant along the main sequence, with 1 per cent of the sources being variable, except at the blue end of the main sequence, between spectral types F0 and F5, where the fraction of variable sources increases to about 2 per cent. For bluer sources, above the main sequence, this percentage increases to about 3.5. We find that the combination of the sampling and the number of observations allows us to determine the variability time-scales and amplitudes for a maximum of 40 per cent of the variables found. About a third of the total number of short time-scale variables found in the survey were not detected in either B or/and I band. These show a similar variability time-scale distribution to that found for the variables detected in all three bands.