A fast hybrid algorithm for exoplanetary transit searches
A fast hybrid algorithm for exoplanetary transit searches
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DOI：
10.1111/j.1365-2966.2006.11074.x
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发表时间：
2006-09
影响因子：
4.8
通讯作者：
A. Cameron;D. Pollacco;R. Street;T. Lister;T. Lister;R. West;D. Wilson;F. Pont;D. Christian-D.-Christ
中科院分区：
文献类型：
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作者：
A. Cameron;D. Pollacco;R. Street;T. Lister;T. Lister;R. West;D. Wilson;F. Pont;D. Christian-D.-Christ
我们提出了一个快速，高效的混合算法选择外行星候选人从广域过境调查。我们的方法是基于广泛使用的SysRem和框最小二乘（BLS）算法。使用SysRem算法映射和消除帧上所有恒星共有的系统误差模式。剩余的系统误差所造成的空间局部化平场和其他错误量化使用boxcar平滑方法。我们发现，搜索参数空间的尺寸可以大大减少，通过进行初始BLS搜索的粗网格上的减少的尺寸，其次是牛顿-拉夫森细化的过境参数附近的最重要的解决方案。我们说明了该方法的操作，将其应用到数据从一个领域的SuperWASP调查，包括2300观测7840颗恒星亮于V = 13.0。我们确定了11个可能的过境候选人。我们拒绝恒星表现出显着的椭球变化造成的指示恒星质量的同伴。我们利用两微米全天巡天和USNO-B1.0巡天的颜色和自行来估计恒星参数和伴星半径。我们发现，两颗恒星显示明确的过境信号通过所有这些测试，因此有资格进行详细的高分辨率光谱跟踪。
We present a fast and efficient hybrid algorithm for selecting exoplanetary candidates from wide-field transit surveys. Our method is based on the widely used SysRem and Box Least-Squares (BLS) algorithms. Patterns of systematic error that are common to all stars on the frame are mapped and eliminated using the SysRem algorithm. The remaining systematic errors caused by spatially localized flat-fielding and other errors are quantified using a boxcar-smoothing method. We show that the dimensions of the search-parameter space can be reduced greatly by carrying out an initial BLS search on a coarse grid of reduced dimensions, followed by Newton-Raphson refinement of the transit parameters in the vicinity of the most significant solutions. We illustrate the method's operation by applying it to data from one field of the SuperWASP survey, comprising 2300 observations of 7840 stars brighter than V = 13.0. We identify 11 likely transit candidates. We reject stars that exhibit significant ellipsoidal variations caused indicative of a stellar-mass companion. We use colours and proper motions from the Two Micron All Sky Survey and USNO-B1.0 surveys to estimate the stellar parameters and the companion radius. We find that two stars showing unambiguous transit signals pass all these tests, and so qualify for detailed high-resolution spectroscopic follow-up.