我们提出了一个层次贝叶斯方法估计银河系的总质量和质量分布。新的分层贝叶斯方法进一步改进了Eadie,Harris,& Widrow(2015)和Eadie & Harris(2016)提出的框架,并建立在Eadie et al(2015a,c)的初步报告基础上。该方法使用分布函数$f(\mathcal{E},L)$来模拟星系和运动学数据从卫星物体,如球状星团(GC)跟踪银河系的引力势。该方法的一个主要优点是,它不仅包括完整和不完整的数据同时在分析中,而且还纳入了测量不确定性在一个连贯的和有意义的方式。我们首先使用Eadie & Harris(2016)中假设的相同数据和幂律模型测试了分层贝叶斯框架,其中包括测量不确定性,并发现结果相似但更强的约束。接下来,我们利用新的统计框架并结合所有可能的GC数据,找到具有贝叶斯可信区域的累积质量分布。该图谱表明$4.8\times10^{11}M_{\odot}$的质量在$125$ kpc内,具有$(4.0-5.8)\times10^{11}M_{\odot}$的95\%贝叶斯可信区域。我们的研究结果还提供了所有GC的真实比能的估计。通过将这些估计的能量与具有完整速度测量的GC的测量能量进行比较,我们观察到具有完整测量的(少数)远程示踪剂可能在确定银河系的总质量估计中发挥很大作用。因此,我们的研究强调需要更多的远程示踪剂与完整的速度测量。
英文摘要:
We present a hierarchical Bayesian method for estimating the total mass and mass profile of the Milky Way Galaxy. The new hierarchical Bayesian approach further improves the framework presented by Eadie, Harris, & Widrow (2015) and Eadie & Harris (2016) and builds upon the preliminary reports by Eadie et al (2015a,c). The method uses a distribution function $f(\mathcal{E},L)$ to model the galaxy and kinematic data from satellite objects such as globular clusters (GCs) to trace the Galaxy's gravitational potential. A major advantage of the method is that it not only includes complete and incomplete data simultaneously in the analysis, but also incorporates measurement uncertainties in a coherent and meaningful way. We first test the hierarchical Bayesian framework, which includes measurement uncertainties, using the same data and power-law model assumed in Eadie & Harris (2016), and find the results are similar but more strongly constrained. Next, we take advantage of the new statistical framework and incorporate all possible GC data, finding a cumulative mass profile with Bayesian credible regions. This profile implies a mass within $125$kpc of $4.8\times10^{11}M_{\odot}$ with a 95\% Bayesian credible region of $(4.0-5.8)\times10^{11}M_{\odot}$. Our results also provide estimates of the true specific energies of all the GCs. By comparing these estimated energies to the measured energies of GCs with complete velocity measurements, we observe that (the few) remote tracers with complete measurements may play a large role in determining a total mass estimate of the Galaxy. Thus, our study stresses the need for more remote tracers with complete velocity measurements.
The DREAMS Project: A New Suite of 1,024 Simulations to Contextualize the Milky Way and Assess Physics Uncertainties
Princeton University(普林斯顿大学);Flatiron Institute(平顿研究所);University of Virginia(弗吉尼亚大学);Rutgers, the State University of New Jersey(新泽西州立罗格斯大学);University of Chicago(芝加哥大学);University of California, San Diego(加州大学圣地亚哥分校);University of Pennsylvania(宾夕法尼亚大学);Massachusetts Institute of Technology(麻省理工学院)
Orbits of massive satellite galaxies: II. Bayesian Estimates of the Milky Way and Andromeda masses using high precision astrometry and cosmological simulations
The DREAMS Project: Disentangling the Impact of Halo-to-Halo Variance and Baryonic Feedback on Milky Way Satellite Galaxies
Princeton University(普林斯顿大学);Flatiron Institute(西蒙斯平铺研究所);University of Virginia(弗吉尼亚大学);Rutgers, the State University of New Jersey(罗格斯,新泽西州立大学);Stockholm University(斯德哥尔摩大学);Northwestern University(西北大学);University of California, San Diego(加州大学圣地亚哥分校);University of Pennsylvania(宾夕法尼亚大学);Massachusetts Institute of Technology(麻省理工学院);University of New Mexico(新墨西哥大学);Yale University(耶鲁大学);University of Texas at Austin(得克萨斯大学奥斯汀分校);University of Washington(华盛顿大学)
MADE: A spectroscopic Mass, Age, and Distance Estimator for red giant stars with Bayesian machine learning
我们提出了一种新的方法(MADE),产生的质量,年龄和距离估计红巨星的天体测量,光度和光谱数据的组合。该方法的核心是贝叶斯人工神经网络(ANN),学习和完全取代恒星等时线。人工神经网络的训练使用的样本红巨星的质量估计从asteroseismology。贝叶斯等时线管道使用天体测量、光度测量、光谱和星震学数据来确定训练输出的后验分布:质量、年龄和距离。考虑到输入的不确定性和ANN参数的不确定性,给定新的输入,计算输出的后验预测分布。我们将MADE应用于$\sim10\,000$红巨星,在APO星系演化实验(APOGEE,Abolfathi et al. 2018)和Tycho-Gaia天体测量解决方案(TGAS,Michalik et al. 2015)发布的14个$^{\mathrm{th}}$数据之间的重叠。人工神经网络是能够减少质量,年龄和距离估计的不确定性,通过贝叶斯等时线管道分配的高输出不确定性的训练集的明星。质量的分数不确定度为$<10\%$,年龄的分数不确定度介于$10$和$25\%$之间。此外,我们的人工神经网络预测整个APOGEE-TGAS恒星目录的质量,年龄和距离所需的时间与贝叶斯等时线管道在少数恒星上运行所需的时间相似。我们得到的目录清楚地显示了预期的厚和薄盘组件在[M/H]-[ $α$ /M]平面,当检查年龄。
Estimating accretion times of halo substructures in the Milky Way
National Astronomical Observatories, Chinese Academy of Sciences(中国科学院国家天文台);Astronomical Institute, Tohoku University(东北大学天文学研究所);Institute for Frontiers in Astronomy and Astrophysics, Beijing Normal University(北京师范大学前沿天文与天体物理研究所);School of Astronomy and Space Science, University of Chinese Academy of Sciences(中国科学院大学天文与空间科学学院)
A Self-Consistent Jeans Analysis of the Milky Way Rotation Curve
Tsinghua University(清华大学);LIRA, Observatoire de Paris, Université PSL, CNRS(巴黎天文台 LIRA 实验室,巴黎大学,法国国家科学研究中心);Center for Astronomy, Space Science and Astrophysics, Independent University, Bangladesh(孟加拉独立大学天体物理学、空间科学与天文学中心);Local Universe and Time-Domain Astronomy Laboratory, Department of Astronomy, China West Normal University(西华师范大学天文学院本地宇宙与时域天文实验室)
A Complete Spectroscopic Survey of the Milky Way satellite Segue 1: Dark matter content, stellar membership and binary properties from a Bayesian analysis
Measuring the alpha-abundance of subsolar-metallicity stars in the Milky Way's central half-parsec: testing globular cluster and dwarf galaxy infall scenarios
Deep Synoptic Array science: a 50 Mpc fast radio burst constrains the mass of the Milky Way circumgalactic medium
我们提出的深层天气阵列(DSA-110)的发现和干涉定位到目前为止,非重复FRB 20220319 D。FRB起源于一个年轻的、快速形成恒星的棒旋星系IRAS 02044 $+$ 7048,它的质量只有50 Mpc。虽然NE 2001和YMW 16模型的银河系星际介质(ISM)的DM的FRB 20220319 D的贡献超过其总观测DM,我们表明,在这些模型中的不确定性容纳的爆发河外起源。我们推导出一个保守的上限DM贡献的环银河系介质(CGM)的银河系:限制是28.7 pc cm $^{-3}$和47.3 pc cm $^{-3}$,这取决于两个恒星附近的天空FRB 20220319 D是用来估计ISM DM。这些极限都意味着银河系CGM的总质量是$<10^{11}M_{\odot}$,而银河系的重子质量是给定总晕质量的宇宙学平均值的$\lesssim60\%$。当遥远的球状星团M53中的双星DM被另外考虑时,可能会有更严格但不那么保守的约束。虽然我们的约束条件是敏感的CGM中可能的各向异性和假设的形式的径向密度分布,它们不受CGM的化学和热性质的不确定性。我们的研究结果强烈支持星系形成模拟通常预测的情况,其中反馈过程从像银河系这样的星系晕中驱逐重子物质。
Forward-modelling Milky Way Cepheids: selection effects and physical priors in the Gaia-HST calibration
University of Oxford(牛津大学);Space Telescope Science Institute(太空望远镜科学研究所);Johns Hopkins University(约翰斯·霍普金斯大学);University of Portsmouth(朴茨茅斯大学);CNRS & Sorbonne Université(法国国家科学研究中心与索邦大学);Duke University(杜克大学)
The DREAMS Project: Disentangling the Impact of Halo-to-Halo Variance and Baryonic Feedback on Milky Way Dark Matter Speed Distributions
Princeton University(普林斯顿大学);Flatiron Institute(西蒙斯平铺研究所);University of Virginia(弗吉尼亚大学);The NSF-Simons AI Institute for Cosmic Origins(NSF-Simons宇宙起源人工智能研究所);Stockholm University(斯德哥尔摩大学);University of Chicago(芝加哥大学);University of Pennsylvania(宾夕法尼亚大学);Massachusetts Institute of Technology(麻省理工学院);Rutgers, the State University of New Jersey(新泽西州立罗格斯大学);University of Texas at Austin(得克萨斯大学奥斯汀分校)
Dark Matter Velocity Distributions for Direct Detection: Astrophysical Uncertainties are Smaller Than They Appear
Princeton University(普林斯顿大学);The Pennsylvania State University(宾夕法尼亚州立大学);Stockholm University(斯德哥尔摩大学);Flatiron Institute(平顿研究所);Massachusetts Institute of Technology(麻省理工学院);Harvard & Smithsonian(哈佛与史密森尼学会)