Annual Review of Astronomy and Astrophysics最新文献_第6页

Wave Dark Matter 波浪暗物质

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2021-01-27 DOI: 10.1146/annurev-astro-120920-010024

L. Hui

{"title":"Wave Dark Matter","authors":"L. Hui","doi":"10.1146/annurev-astro-120920-010024","DOIUrl":"https://doi.org/10.1146/annurev-astro-120920-010024","url":null,"abstract":"We review the physics and phenomenology of wave dark matter: a bosonic dark matter candidate lighter than about 30 eV. Such particles have a de Broglie wavelength exceeding the average interparticle separation in a galaxy like the Milky Way and are, thus, well described as a set of classical waves. We outline the particle physics motivations for such particles, including the quantum chromodynamics axion as well as ultralight axion-like particles such as fuzzy dark matter. The wave nature of the dark matter implies a rich phenomenology: ▪ Wave interference gives rise to order unity density fluctuations on de Broglie scale in halos. One manifestation is vortices where the density vanishes and around which the velocity circulates. There is one vortex ring per de Broglie volume on average. ▪ For sufficiently low masses, soliton condensation occurs at centers of halos. The soliton oscillates and undergoes random walks, which is another manifestation of wave interference. The halo and subhalo abundance is expected to be suppressed at small masses, but the precise prediction from numerical wave simulations remains to be determined. ▪ For ultralight ∼10−22 eV dark matter, the wave interference substructures can be probed by tidal streams or gravitational lensing. The signal can be distinguished from that due to subhalos by the dependence on stream orbital radius or image separation. ▪ Axion detection experiments are sensitive to interference substructures for wave dark matter that is moderately light. The stochastic nature of the waves affects the interpretation of experimental constraints and motivates the measurement of correlation functions. Current constraints and open questions, covering detection experiments and cosmological, galactic, and black hole observations, are discussed.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45613249","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: 135

First Multimessenger Observations of a Neutron Star Merger 中子星合并的首次多信使观测

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-12-09 DOI: 10.1146/annurev-astro-112420-030742

R. Margutti, R. Chornock

{"title":"First Multimessenger Observations of a Neutron Star Merger","authors":"R. Margutti, R. Chornock","doi":"10.1146/annurev-astro-112420-030742","DOIUrl":"https://doi.org/10.1146/annurev-astro-112420-030742","url":null,"abstract":"We describe the first observations of the same celestial object with gravitational waves and light. ▪ GW170817 was the first detection of a neutron star merger with gravitational waves. ▪ The detection of a spatially coincident weak burst of gamma-rays (GRB 170817A) 1.7 s after the merger constituted the first electromagnetic detection of a gravitational wave source and established a connection between at least some cosmic short gamma-ray bursts (SGRBs) and binary neutron star mergers. ▪ A fast-evolving optical and near-infrared transient (AT 2017gfo) associated with the event can be interpreted as resulting from the ejection of ∼0.05 M⊙ of material enriched in r-process elements, finally establishing binary neutron star mergers as at least one source of r-process nucleosynthesis. ▪ Radio and X-ray observations revealed a long-rising source that peaked ∼[Formula: see text] after the merger. Combined with the apparent superluminal motion of the associated very long baseline interferometry source, these observations show that the merger produced a relativistic structured jet whose core was oriented ≈20 deg from the line of sight and with properties similar to SGRBs. The jet structure likely results from interaction between the jet and the merger ejecta. ▪ The electromagnetic and gravitational wave information can be combined to produce constraints on the expansion rate of the Universe and the equation of state of dense nuclear matter. These multimessenger endeavors will be a major emphasis for future work. Expected final online publication date for the Annual Review of Astronomy and Astrophysics, Volume 59 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2020-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48491681","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: 46

Evolution and Mass Loss of Cool Aging Stars: A Daedalean Story 冷却老化恒星的演化和质量损失:一个代达林的故事

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-11-26 DOI: 10.1146/annurev-astro-090120-033712

L. Decin

{"title":"Evolution and Mass Loss of Cool Aging Stars: A Daedalean Story","authors":"L. Decin","doi":"10.1146/annurev-astro-090120-033712","DOIUrl":"https://doi.org/10.1146/annurev-astro-090120-033712","url":null,"abstract":"A multitude of phenomena—such as the chemical enrichment of the Universe, the mass spectrum of planetary nebulae, white dwarfs and gravitational wave progenitors, the frequency distribution of supernovae, the fate of exoplanets, etc.—are highly regulated by the amounts of mass that stars expel through a powerful wind. For more than half a century, these winds of cool aging stars have been interpreted within the common interpretive framework of 1D models. I here discuss how that framework now appears to be highly problematic. • Current 1D mass-loss rate formulae differ by orders of magnitude, rendering contemporary stellar evolution predictions highly uncertain. These stellar winds harbor 3D complexities that bridge 23 orders of magnitude in scale, ranging from the nanometer up to thousands of astronomical units. We need to embrace and understand these 3D spatial realities if we aim to quantify mass loss and assess its effect on stellar evolution. We therefore need to gauge the following: • The 3D life of molecules and solid-state aggregates: The gas-phase clusters that form the first dust seeds are not yet identified. This limits our ability to predict mass-loss rates using a self-consistent approach. • The emergence of 3D clumps: They contribute in a nonnegligible way to the mass loss, although they seem of limited importance for the wind-driving mechanism. • The 3D lasting impact of a (hidden) companion: Unrecognized binary interaction has biased previous mass-loss rate estimates toward values that are too large. Only then will it be possible to drastically improve our predictive power of the evolutionary path in 4D (classical) spacetime of any star. Expected final online publication date for the Annual Review of Astronomy and Astrophysics, Volume 59 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2020-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42231187","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: 13

The Roles of Astronomers in the Astronomy Education Ecosystem: A Research-Based Perspective 天文学家在天文学教育生态系统中的作用:一个基于研究的视角

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-11-23 DOI: 10.1146/annurev-astro-032620-021943

S. Pompea, P. Russo

引用次数: 12

Observational Constraints on Black Hole Spin 黑洞自旋的观测约束

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-11-17 DOI: 10.1146/annurev-astro-112420-035022

C. Reynolds

{"title":"Observational Constraints on Black Hole Spin","authors":"C. Reynolds","doi":"10.1146/annurev-astro-112420-035022","DOIUrl":"https://doi.org/10.1146/annurev-astro-112420-035022","url":null,"abstract":"The spin of a black hole is an important quantity to study, providing a window into the processes by which a black hole was born and grew. Furthermore, spin can be a potent energy source for powering relativistic jets and energetic particle acceleration. In this review, I describe the techniques currently used to detect and measure the spins of black holes. It is shown that: ▪ Two well-understood techniques, X-ray reflection spectroscopy and thermal continuum fitting, can be used to measure the spins of black holes that are accreting at moderate rates. There is a rich set of other electromagnetic techniques allowing us to extend spin measurements to lower accretion rates. ▪ Many accreting supermassive black holes are found to be rapidly spinning, although a population of more slowly spinning black holes emerges at masses above M > 3 × 107 M⊙ expected from recent structure formation models. ▪ Many accreting stellar-mass black holes in X-ray binary systems are rapidly spinning and must have been born in this state. ▪ The advent of gravitational wave astronomy has enabled the detection of spin effects in merging binary black holes. Most of the premerger black holes are found to be slowly spinning, a notable exception being an object that may itself be a merger product. ▪ The stark difference in spins between the black hole X-ray binary and the binary black hole populations shows that there is a diversity of formation mechanisms. Given the array of new electromagnetic and gravitational wave capabilities currently being planned, the future of black hole spin studies is bright. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46828474","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: 65

New Insights into Classical Novae 对古典小说的新见解

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-11-17 DOI: 10.1146/annurev-astro-112420-114502

L. Chomiuk, B. Metzger, K. Shen

{"title":"New Insights into Classical Novae","authors":"L. Chomiuk, B. Metzger, K. Shen","doi":"10.1146/annurev-astro-112420-114502","DOIUrl":"https://doi.org/10.1146/annurev-astro-112420-114502","url":null,"abstract":"We survey our understanding of classical novae—nonterminal, thermonuclear eruptions on the surfaces of white dwarfs in binary systems. The recent and unexpected discovery of GeV gamma rays from Galactic novae has highlighted the complexity of novae and their value as laboratories for studying shocks and particle acceleration. We review half a century of nova literature through this new lens, and conclude the following: ▪ The basics of the thermonuclear runaway theory of novae are confirmed by observations. The white dwarf sustains surface nuclear burning for some time after runaway, and until recently, it was commonly believed that radiation from this nuclear burning solely determines the nova's bolometric luminosity. ▪ The processes by which novae eject material from the binary system remain poorly understood. Mass loss from novae is complex (sometimes fluctuating in rate, velocity, and morphology) and often prolonged in time over weeks, months, or years. ▪ The complexity of the mass ejection leads to gamma-ray-producing shocks internal to the nova ejecta. When gamma rays are detected (around optical maximum), the shocks are deeply embedded and the surrounding gas is very dense. ▪ Observations of correlated optical and gamma-ray light curves confirm that the shocks are radiative and contribute significantly to the bolometric luminosity of novae. Novae are therefore the closest and most common interaction-powered transients. Expected final online publication date for the Annual Review of Astronomy and Astrophysics, Volume 59 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.","PeriodicalId":8138,"journal":{"name":"Annual Review of Astronomy and Astrophysics","volume":" ","pages":""},"PeriodicalIF":33.3,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49457330","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: 41

Evidence for Initial Mass Function Variation in Massive Early-Type Galaxies 大质量早期型星系初始质量函数变化的证据

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-10-26 DOI: 10.1146/annurev-astro-032620-020217

Russell J. Smith

引用次数: 20

Magnetohydrodynamics Simulations of Active Galactic Nucleus Disks and Jets 活动星系核盘和喷流的磁流体动力学模拟

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-10-26 DOI: 10.1146/annurev-astro-081817-051905

S. Davis, A. Tchekhovskoy

引用次数: 48

Magnetohydrodynamic Waves in the Solar Corona 太阳日冕中的磁流体动力学波

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-10-26 DOI: 10.1146/annurev-astro-032320-042940

V. Nakariakov, D. Kolotkov

引用次数: 70

Jack of All 杰克

IF 33.3 1区物理与天体物理

Annual Review of Astronomy and Astrophysics Pub Date : 2020-08-18 DOI: 10.1146/annurev-astro-112119-041947

J. Gunn

引用次数: 3