Annual Review of Astronomy and Astrophysics最新文献_第9页

Cosmology Paradigm Changes 宇宙学范式的改变

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2018-09-14 DOI: 10.1146/ANNUREV-ASTRO-081817-051748

J. Einasto

引用次数: 0

Dynamical Evolution of the Early Solar System 早期太阳系的动力演化

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2018-07-17 DOI: 10.1146/annurev-astro-081817-052028

D. Nesvorný

{"title":"Dynamical Evolution of the Early Solar System","authors":"D. Nesvorný","doi":"10.1146/annurev-astro-081817-052028","DOIUrl":"https://doi.org/10.1146/annurev-astro-081817-052028","url":null,"abstract":"Several properties of the Solar System, including the wide radial spacing of the giant planets, can be explained if planets radially migrated by exchanging orbital energy and momentum with outer disk planetesimals. Neptune's planetesimal-driven migration, in particular, has a strong advocate in the dynamical structure of the Kuiper belt. A dynamical instability is thought to have occurred during the early stages with Jupiter having close encounters with a Neptune-class planet. As a result of the encounters, Jupiter acquired its current orbital eccentricity and jumped inward by a fraction of an astronomical unit, as required for the survival of the terrestrial planets and from asteroid belt constraints. Planetary encounters also contributed to capture of Jupiter Trojans and irregular satellites of the giant planets. Here we discuss the dynamical evolution of the early Solar System with an eye to determining how models of planetary migration/instability can be constrained from its present architecture. Specifically, we review arguments suggesting that the Solar System may have originally contained a third ice giant on a resonant orbit between Saturn and Uranus. This hypothesized planet was presumably ejected into interstellar space during the instability. The Kuiper belt kernel and other dynamical structures in the trans-Neptunian region may provide evidence for the ejected planet. We favor the early version of the instability where Neptune migrated into the outer planetesimal disk within a few tens of millions of years after the dispersal of the protosolar nebula. If so, the planetary migration/instability was not the cause of the Late Heavy Bombardment. Mercury's orbit may have been excited during the instability.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2018-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-astro-081817-052028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42542366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 156

Obscured Active Galactic Nuclei 暗活动星系核

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2018-06-12 DOI: 10.1146/annurev-astro-081817-051803

R. Hickox, D. Alexander

引用次数: 199

Chemodynamical History of the Galactic Bulge 星系凸起的化学动力学史

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2018-05-03 DOI: 10.1146/annurev-astro-081817-051826

B. Barbuy, C. Chiappini, Ortwin Gerhard

{"title":"Chemodynamical History of the Galactic Bulge","authors":"B. Barbuy, C. Chiappini, Ortwin Gerhard","doi":"10.1146/annurev-astro-081817-051826","DOIUrl":"https://doi.org/10.1146/annurev-astro-081817-051826","url":null,"abstract":"The Galactic Bulge can uniquely be studied from large samples of individual stars and is therefore of prime importance for understanding the stellar population structure of bulges in general. Here the observational evidence on the kinematics, chemical composition, and ages of Bulge stellar populations based on photometric and spectroscopic data is reviewed. The bulk of Bulge stars are old and span a metallicity range of −1.5≲[Fe/H]≲+0.5. Stellar populations and chemical properties suggest a star-formation timescale below ∼2 Gyr. The overall Bulge is barred and follows cylindrical rotation, and the more metal-rich stars trace a box/peanut (B/P) structure. Dyna-mical models demonstrate the different spatial and orbital distributions of metal-rich and metal-poor stars. We discuss current Bulge-formation scenarios based on dynamical, chemical, chemodynamical, and cosmological models. Despite impressive progress, we do not yet have a successful fully self-consistent chemodynamical Bulge model in the cosmological framework, and we will also need a more extensive chrono-chemical-kinematic 3D map of stars to better constrain such models.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2018-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-astro-081817-051826","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44612390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 102

The Connection Between Galaxies and Their Dark Matter Halos 星系与其暗物质晕之间的联系

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2018-04-09 DOI: 10.1146/annurev-astro-081817-051756

R. Wechsler, J. Tinker

{"title":"The Connection Between Galaxies and Their Dark Matter Halos","authors":"R. Wechsler, J. Tinker","doi":"10.1146/annurev-astro-081817-051756","DOIUrl":"https://doi.org/10.1146/annurev-astro-081817-051756","url":null,"abstract":"In our modern understanding of galaxy formation, every galaxy forms within a dark matter halo. The formation and growth of galaxies over time is connected to the growth of the halos in which they form. The advent of large galaxy surveys as well as high-resolution cosmological simulations has provided a new window into the statistical relationship between galaxies and halos and its evolution. Here, we define this galaxy–halo connection as the multivariate distribution of galaxy and halo properties that can be derived from observations and simulations. This galaxy–halo connection provides a key test of physical galaxy-formation models; it also plays an essential role in constraints of cosmological models using galaxy surveys and in elucidating the properties of dark matter using galaxies. We review techniques for inferring the galaxy–halo connection and the insights that have arisen from these approaches. Some things we have learned are that galaxy-formation efficiency is a strong function of halo mass; at its peak in halos around a pivot halo mass of 1012M⊙, less than 20% of the available baryons have turned into stars by the present day; the intrinsic scatter in galaxy stellar mass is small, less than 0.2 dex at a given halo mass above this pivot mass; below this pivot mass galaxy stellar mass is a strong function of halo mass; the majority of stars over cosmic time were formed in a narrow region around this pivot mass. We also highlight key open questions about how galaxies and halos are connected, including understanding the correlations with secondary properties and the connection of these properties to galaxy clustering.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2018-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-astro-081817-051756","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47912049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 364

Debris Disks: Structure, Composition, and Variability 碎片盘:结构、组成和可变性

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2018-02-12 DOI: 10.1146/annurev-astro-081817-052035

A. Hughes, G. Duchêne, G. Duchêne, B. Matthews, B. Matthews

{"title":"Debris Disks: Structure, Composition, and Variability","authors":"A. Hughes, G. Duchêne, G. Duchêne, B. Matthews, B. Matthews","doi":"10.1146/annurev-astro-081817-052035","DOIUrl":"https://doi.org/10.1146/annurev-astro-081817-052035","url":null,"abstract":"Debris disks are tenuous, dust-dominated disks commonly observed around stars over a wide range of ages. Those around main sequence stars are analogous to the Solar System's Kuiper Belt and zodiacal light. The dust in debris disks is believed to be continuously regenerated, originating primarily with collisions of planetesimals. Observations of debris disks provide insight into the evolution of planetary systems; and the composition of dust, comets, and planetesimals outside the Solar System; as well as placing constraints on the orbital architecture and potentially the masses of exoplanets that are not otherwise detectable. This review highlights recent advances in multiwavelength, high-resolution scattered light and thermal imaging that have revealed a complex and intricate diversity of structures in debris disks and discusses how modeling methods are evolving with the breadth and depth of the available observations. Two rapidly advancing subfields highlighted in this review include observations of atomic and molecular gas around main sequence stars and variations in emission from debris disks on very short (days to years) timescales, providing evidence of non-steady-state collisional evolution particularly in young debris disks.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2018-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-astro-081817-052035","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44595112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 172

Origins of Hot Jupiters 热木星的起源

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2018-01-18 DOI: 10.1146/annurev-astro-081817-051853

R. Dawson, J. Johnson

引用次数: 255

Multiple Stellar Populations in Globular Clusters 球状星团中的多重恒星群

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2017-12-04 DOI: 10.1146/annurev-astro-081817-051839

N. Bastian, C. Lardo

{"title":"Multiple Stellar Populations in Globular Clusters","authors":"N. Bastian, C. Lardo","doi":"10.1146/annurev-astro-081817-051839","DOIUrl":"https://doi.org/10.1146/annurev-astro-081817-051839","url":null,"abstract":"Globular clusters (GCs) exhibit star-to-star variations in specific elements (e.g., He, C, N, O, Na, Al) that bear the hallmark of high-temperature H-burning. These abundance variations can be observed spectroscopically and also photometrically, with the appropriate choice of filters, due to the changing of spectral features within the band pass. This phenomenon is observed in nearly all of the ancient GCs, although, to date, it has not been found in any massive cluster younger than 2 Gyr. Many scenarios have been suggested to explain this phenomenon, with most invoking multiple epochs of star formation within the cluster; however, all have failed to reproduce various key observations, in particular when a global view of the GC population is taken. We review the state of current observations and outline the successes and failures of each of the main proposed models. The traditional idea of using the stellar ejecta from a first generation of stars to form a second generation of stars, while conceptually straightforward, has failed to reproduce an increasing number of observational constraints. We conclude that the puzzle of multiple populations remains unsolved, hence alternative theories are needed.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":"1 1","pages":""},"PeriodicalIF":33.3,"publicationDate":"2017-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1146/annurev-astro-081817-051839","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44271912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 330

The Interstellar Dust Properties of Nearby Galaxies 邻近星系的星际尘埃特性

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2017-11-20 DOI: 10.1146/annurev-astro-081817-051900

F. Galliano, F. Galliano, M. Galametz, M. Galametz, A. Jones

引用次数: 115

Weak Lensing for Precision Cosmology 精确宇宙学的弱透镜

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2017-10-09 DOI: 10.1146/annurev-astro-081817-051928

R. Mandelbaum

引用次数: 168