Radial velocity (RV) observations of an exoplanet system giving a value of M_T sin(i) condition (i.e. give information about) not only the planet's true mass M_T but also the value of sin(i) (where i is the orbital inclination angle). Thus the value of sin(i) for a system with any particular observed value of M_T sin(i) cannot be assumed to be drawn randomly from a uniform distribution between zero and unity (corresponding to an isotropic i distribution). The actual distribution from which it is drawn depends on the intrinsic distribution of M_T for the exoplanet population being studied. We give a simple Bayesian derivation of this relationship and apply it to several "toy models" for the (currently unknown) intrinsic distribution of M_T. The results show that the effect can be an important one. For example, even for simple power-law distributions of M_T, the median value of sin(i) in an observed RV sample can vary between 0.25 and 0.71 (as compared to the 0.5 value for an isotropic i distribution) for indices of the power-law in the quite plausible range between -2 and -0.5, respectively. Over the same range of indicies, the 95% confidence upper bound on M_T ranges from 4.5 to 400 times larger than M_T sin(i), respectively, due to sin(i) uncertainty alone. More complex, but still simple and plausible, distributions of M_T yield still more complicated and less intuitive $sin(i)$ distributions. In particular, if the M_T distribution contains any characteristic mass scale M_c, the sin(i) distribution will depend on the ratio of M_T sin(i) to $M_c$, often in a non-trivial way. Our qualitative conclusion is that RV studies of exoplanets, both individual objects and statistical samples, should regard the sin(i) factor as more than a "numerical constant of order unity" with simple and well understood statistical properties. (abridged)
Orbits for the Impatient: A Bayesian Rejection Sampling Method for Quickly Fitting the Orbits of Long-Period Exoplanets
我们描述了一个贝叶斯拒绝抽样算法,旨在有效地计算后验分布的轨道要素的数据覆盖的长周期系外行星轨道的短分数。我们的实现这种方法,轨道的不耐烦(OFTI),收敛到几个数量级的速度比两个实现MCMC在这个政权。我们说明了我们的方法的效率,显示OFTI计算准确的后验的所有现有的天体测量的系外行星51 Eri b高达100倍的速度比大都会黑斯廷斯MCMC。我们证明了OFTI的准确性,通过比较我们的结果为几个轨道系统与各种MCMC实现,发现输出后验是相同的散粒噪声。我们还描述了如何使用我们的算法成功地预测了位置51 Eri b在未来六个月的基础上不到三个月的天体测量。最后,我们将OFTI应用于10颗长周期系外行星和褐矮星,除了一颗外,所有这些行星和褐矮星的轨道都被监测到不到3%,从文献中的天体测量记录中产生适合它们的轨道。
FlopPITy: Enabling self-consistent exoplanet atmospheric retrievals with machine learning
Kapteyn Astronomical Institute, University of Groningen(格罗宁根大学卡普坦天文研究所);Netherlands Space Research Institute (SRON)(荷兰空间研究所(SRON));Centre for Exoplanet Science, University of Edinburgh(爱丁堡大学系外行星科学中心);School of GeoSciences, University of Edinburgh(爱丁堡大学地球科学学院)
The Efficiency of Geometric Samplers for Exoplanet Transit Timing Variation Models
凌日时变(TTV)是确定多行星系统中凌日行星质量和轨道的重要工具。如果知道相互作用的行星的轨道结构和行星-恒星质量比,TTV可以很容易地建模,但这样的模型是高度非线性的,很难反演。马尔可夫链蒙特卡罗(MCMC)方法通常用于探索模型参数的后验分布,但是,由于参数之间的高度相关性,非线性和后验中潜在的多模态,许多采样器的效率非常低。因此,我们评估了几个MCMC采样器,使用不同程度的几何信息的目标分布的性能。我们从多个模型生成合成数据集,包括TTVFaster模型和一个简单的正弦模型,并测试各种MCMC采样器的效率。我们发现,采样效率可以大大提高所有模型的采样从一个参数空间转换使用的协方差估计和目标分布的手段。没有一个采样器对所有数据集都表现最好,但有几个采样器,如差分进化蒙特卡罗和几何自适应蒙特卡罗,具有一致的高效性能。对于具有近高斯后验的数据集,具有2或3个蛙跳步骤的Hamilton Monte Carlo采样器获得了最高的效率。基于每次有效样本量的差异,我们表明,正确选择采样器可以提高采样效率的几个数量级。
Machine Learning and Deep Learning for Exoplanet Detection and Atmospheric Characterization with JWST and the Upcoming Ariel Mission
Department of Industrial Physics, Enugu State University of Science and Technology(恩古州科技大学工业物理系);Department of Physics, Dennis Osadebay University(德尼斯·奥萨德贝大学物理系)
Improving exoplanet detection capabilities with the false inclusion probability. Comparison with other detection criteria in the context of radial velocities
Jointly Modeling Roman Coronagraph Astrometry and Photometry Improves Orbital Parameter Estimates
Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University(西北大学跨学科天体物理探索与研究中心);Department of Physics and Engineering, University of St. Thomas(圣托马斯大学物理与工程系);Department of Astronomy and Astrophysics, University of California, Santa Cruz(加州大学圣克鲁斯分校天文与天体物理系)
The Exoplanet Orbit Database II: Updates to exoplanets.org
系外行星轨道数据库(EOD)汇编了同行评审文献中报告的轨道,过境,宿主恒星和其他参数。EOD可以通过系外行星数据探测器(EDE)绘图仪和表格进行导航,该绘图仪和表格可在万维网上的exoplanets.org上找到。EOD包含截至2014年7月的1492颗确认的系外行星的数据。EOD来源于Butler et al.(2002)和Catalog of Nearby Exoplanets(Butler et al. 2006)中的表格,第一个完整的EOD和EDE文件是Wright et al.(2011)。在这篇文章中,我们描述了我们从那时起的工作。我们已经扩大了EOD的范围,包括二次日食参数,不对称的不确定性,并扩大了EDE,包括3000多个开普勒感兴趣的对象(KOI)的样本,和其他没有良好的轨道参数的真实行星(如许多微透镜和成像检测)。用户可以从exoplanets.org的首页下载整个EOD的最新版本,作为一个逗号分隔的值文件。
The CARMENES search for exoplanets around M dwarfs. Revisiting the GJ 581 multi-planetary system with new Doppler measurements from CARMENES, HARPS, and HIRES
Department of Physics, University of Warwick(沃里克大学物理系);Centre for Exoplanets and Habitability, University of Warwick(沃里克大学系外行星与宜居性中心);Instituto de Ciencias Físicas (CONICET / ECyT-UNSAM)(物理科学研究所(CONICET / ECyT-UNSAM));Gerencia de Tecnología de la información y de las Comunicaciones (GTIC), Subgerencia Vinculación y Desarrollo de Nuevas Tecnologías de la Información, DTE-CNEA. Centro Atómico Constituyentes(信息与通信技术管理局(GTIC),技术联络与发展新技术子部门,DTE-CNEA原子构成中心);Instituto Tecnológico de Buenos Aires (ITBA)(布宜诺斯艾利斯技术研究所)
Simulation-based Inference for Exoplanet Atmospheric Retrieval: Insights from winning the Ariel Data Challenge 2023 using Normalizing Flows
AstroAI;Ecole Polytechnique(巴黎综合理工学院);Institute of Theory and Computation(理论与计算研究所);Massachusetts Institute of Technology(麻省理工学院);University of Southampton(南安普顿大学);Kavli Institute for Astrophysics and Space Research(卡弗里天体物理与空间研究所)
Detecting and Characterizing Companions with a Calibrated Gaia DR2, DR3, and Hipparcos Catalog (G23H)
NRC Herzberg Astronomy and Astrophysics(国家研究委员会赫茨伯格天文学与天体物理学研究所);Department of Physics and Astronomy, University of Victoria(维多利亚大学物理与天文系);Heising-Simons Foundation(海辛-西蒙斯基金会);Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles(加州大学洛杉矶分校地球、行星与空间科学系);Department of Physics, University of California, Santa Barbara(加州大学圣塔芭芭拉分校物理系);Department of Astronomy & Astrophysics, University of California, San Diego(加州大学圣地亚哥分校天文与天体物理学系);Department of Astronomy, New Mexico State University(新墨西哥州立大学天文系)
Synthesizing Exoplanet Demographics: A Single Population of Long-Period Planetary Companions to M Dwarfs Consistent with Microlensing, Radial Velocity, and Direct Imaging Surveys
We present the first study to synthesize results from five different exoplanet surveys using three independent detection methods: microlensing, radial velocity, and direct imaging. The constraints derived herein represent the most comprehensive picture of the demographics of large-separation (>~ 2 AU) planets orbiting the most common stars in our Galaxy that has been constructed to date. We assume a simple, joint power-law planet distribution function of the form d^2 N_{pl} /[dlog(m_p)dlog(a)] = A(m_p/ M_{Sat} )^{alpha}(a/2.5 AU)^{beta} with an outer cutoff radius of the separation distributio…
我们提出了一个数据库,以及确定的系外行星的轨道参数。这个数据库包括光谱轨道要素测量427行星绕363颗恒星的径向速度和过境测量报告中的文献。我们还编制了基本的过境参数,恒星参数,以及用于行星发现的方法。这个系外行星轨道数据库包括同行评审文章中报告的所有具有可靠,测量良好的轨道参数的行星。该数据库可以通过Exoplanets Data Explorer Table在 http://exoplanets.org上以可搜索、可过滤和可排序的形式提供,数据可以通过Exoplanets Data Explorer Plotter绘制和探索。我们使用的数据资源管理器生成出版准备图给出三个例子的签名的系外行星迁移和动力学演化:我们说明的字符的质量和周期的系外行星轨道,径向速度和过境调查之间的选择不同的偏差,和多行星系统显示出明显的半长轴分布从单点系统。
Improving exoplanet mass characterisation with Bayesian model selection using the Learned Harmonic Mean Estimator
Mullard Space Science Laboratory, Department of Space & Climate Physics, University College London(伦敦大学学院穆拉德空间科学实验室空间与气候物理系);Department of Statistical Science, University College London(伦敦大学学院统计科学系)