New Astronomy Reviews最新文献

{"title":"Gamma-ray burst cosmology","authors":"F.Y. Wang ,&nbsp;Z.G. Dai ,&nbsp;E.W. Liang","doi":"10.1016/j.newar.2015.03.001","DOIUrl":"10.1016/j.newar.2015.03.001","url":null,"abstract":"<div><p>Gamma-ray bursts (GRBs) are the most luminous electromagnetic explosions in the Universe, which emit up to 8.8 × 10⁵⁴<span><span> erg isotropic equivalent energy in the hard X-ray band. The high luminosity makes them detectable out to the largest distances yet explored in the Universe. GRBs, as bright beacons in the deep Universe, would be the ideal tool to probe the properties of high-redshift universe: including the cosmic expansion and dark energy<span>, star formation rate<span>, the reionization epoch and the metal enrichment history of the Universe. In this article, we review the luminosity correlations of GRBs, and implications for constraining the </span></span></span>cosmological parameters<span><span> and dark energy. Observations show that the progenitors of long GRBs are massive stars<span>. So it is expected that long GRBs are tracers of star formation rate. We also review the high-redshift star formation rate derived from GRBs, and implications for the cosmic reionization history. The afterglows<span> of GRBs generally have broken power-law spectra, so it is possible to extract intergalactic medium (IGM) absorption features. We also present the capability of high-redshift GRBs to probe the pre-galactic metal enrichment and the </span></span></span>first stars.</span></span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"67 ","pages":"Pages 1-17"},"PeriodicalIF":6.0,"publicationDate":"2015-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2015.03.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84777354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Formation of black hole low-mass X-ray binaries","authors":"Xiang-Dong Li","doi":"10.1016/j.newar.2015.02.001","DOIUrl":"10.1016/j.newar.2015.02.001","url":null,"abstract":"<div><p>The majority of known Galactic black holes reside in low-mass X-ray binaries. They are rare and fascinating objects, providing unique information on strong gravity, accretion disc<span> physics, and stellar and binary evolution. There is no doubt that our understanding of the formation of black hole low-mass X-ray binaries has significantly advanced in the past decade. However, some key issues are still unresolved. In this paper we briefly summarize the observational clues and theoretical progress on the formation of black hole low-mass X-ray binaries.</span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"64 ","pages":"Pages 1-6"},"PeriodicalIF":6.0,"publicationDate":"2015-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2015.02.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84932185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"What Regulates Galaxy Evolution? Open questions in our understanding of galaxy formation and evolution","authors":"Gabriella De Lucia ,&nbsp;Adam Muzzin ,&nbsp;Simone Weinmann","doi":"10.1016/j.newar.2014.08.001","DOIUrl":"10.1016/j.newar.2014.08.001","url":null,"abstract":"<div><p>In April 2013, a workshop entitled “What Regulates Galaxy Evolution<span>?” was held at the Lorentz Center. The aim of the workshop was to bring together the observational and theoretical community working on galaxy evolution, and to discuss in depth of the current problems in the subject, as well as to review the most recent observational constraints. A total of 42 astrophysicists attended the workshop. A significant fraction of the time was devoted to identifying the most interesting “open questions” in the field, and to discuss how progress can be made. This review discusses the four questions (one for each day of the workshop) that, in our opinion, were the focus of the most intense debate. We present each question in its context, and close with a discussion of what future directions should be pursued in order to make progress on these problems.</span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"62 ","pages":"Pages 1-14"},"PeriodicalIF":6.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2014.08.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79061485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"New approaches to SNe Ia progenitors","authors":"Pilar Ruiz-Lapuente","doi":"10.1016/j.newar.2014.08.002","DOIUrl":"10.1016/j.newar.2014.08.002","url":null,"abstract":"<div><p><span>Although Type Ia supernovae (SNe Ia) are a major tool in cosmology and play a key role in the chemical </span>evolution of galaxies<span>, the nature of their progenitor systems (apart from the fact that they must content at least one white dwarf, that explodes) remains largely unknown. In the last decade, considerable efforts have been made, both observationally and theoretically, to solve this problem. Observations have, however, revealed a previously unsuspected variety of events, ranging from very underluminous outbursts to clearly overluminous ones, and spanning a range well outside the peak luminosity-decline rate of the light curve relationship, used to make calibrated candles of the SNe Ia. On the theoretical side, new explosion scenarios, such as violent mergings of pairs of white dwarfs, have been explored. We review those recent developments, emphasizing the new observational findings, but also trying to tie them to the different scenarios and explosion mechanisms proposed thus far.</span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"62 ","pages":"Pages 15-31"},"PeriodicalIF":6.0,"publicationDate":"2014-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2014.08.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90914901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Empirical tests of pre-main-sequence stellar evolution models with eclipsing binaries","authors":"Keivan G. Stassun ,&nbsp;Gregory A. Feiden ,&nbsp;Guillermo Torres","doi":"10.1016/j.newar.2014.06.001","DOIUrl":"10.1016/j.newar.2014.06.001","url":null,"abstract":"<div><p><span><span>We examine the performance of standard pre-main-sequence (PMS) stellar evolution models against the accurately measured properties of a benchmark sample of 26 </span>PMS stars<span> in 13 eclipsing binary (EB) systems having masses 0.04–4.0</span></span> <!-->M_⊙ and nominal ages ≈1–20<!--> <!-->Myr. We provide a definitive compilation of all fundamental properties for the EBs, with a careful and consistent reassessment of observational uncertainties. We also provide a definitive compilation of the various PMS model sets, including physical ingredients and limits of applicability. No set of model isochrones is able to successfully reproduce all of the measured properties of all of the EBs. In the H–R diagram, the masses inferred for the individual stars by the models are accurate to better than 10% at ≳1<!--> <!-->M_⊙, but below 1<!--> <!-->M_⊙<span> they are discrepant by 50–100%. Adjusting the observed radii and temperatures using empirical relations for the effects of magnetic activity helps to resolve the discrepancies in a few cases, but fails as a general solution. We find evidence that the failure of the models to match the data is linked to the triples in the EB sample; at least half of the EBs possess tertiary companions. Excluding the triples, the models reproduce the stellar masses to better than ∼10% in the H–R diagram, down to 0.5</span> <!-->M_⊙<span>, below which the current sample is fully contaminated by tertiaries. We consider several mechanisms by which a tertiary might cause changes in the EB properties and thus corrupt the agreement with stellar model<span> predictions. We show that the energies of the tertiary orbits are comparable to that needed to potentially explain the scatter in the EB properties through injection of heat, perhaps involving tidal interaction<span>. It seems from the evidence at hand that this mechanism, however it operates in detail, has more influence on the surface properties of the stars than on their internal structure, as the lithium abundances are broadly in good agreement with model predictions. The EBs that are members of young clusters appear individually coeval to within 20%, but collectively show an apparent age spread of ∼50%, suggesting true age spreads in young clusters. However, this apparent spread in the EB ages may also be the result of scatter in the EB properties induced by tertiaries.</span></span></span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"60 ","pages":"Pages 1-28"},"PeriodicalIF":6.0,"publicationDate":"2014-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2014.06.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89548246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Dark matter in the Local Universe","authors":"Gustavo Yepes ,&nbsp;Stefan Gottlöber ,&nbsp;Yehuda Hoffman","doi":"10.1016/j.newar.2013.11.001","DOIUrl":"10.1016/j.newar.2013.11.001","url":null,"abstract":"<div><p><span>We review how dark matter is distributed in our local neighbourhood from an observational and theoretical perspective. We will start by describing first the dark matter halo of our own galaxy and in the Local Group. Then we proceed to describe the dark matter distribution<span><span> in the more extended area known as the Local Universe. Depending on the nature of dark matter, numerical simulations predict different abundances of substructures in Local Group galaxies, in the number of void regions and the abundance of low rotational velocity galaxies in the Local Universe. By comparing these predictions with the most recent observations, strong constrains on the physical properties of the dark matter particles can be derived. We devote particular attention to the results from the Constrained Local UniversE Simulations (CLUES) project, a special set of simulations whose initial conditions are constrained by observational data from the Local Universe. The resulting simulations are designed to reproduce the observed structures in the nearby universe. The CLUES provides a numerical laboratory for simulating the Local Group of galaxies and exploring the </span>physics of </span></span>galaxy formation in an environment designed to follow the observed Local Universe. It has come of age as the numerical analogue of Near-Field Cosmology.</p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"58 ","pages":"Pages 1-18"},"PeriodicalIF":6.0,"publicationDate":"2014-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2013.11.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76059311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"A complete reference of the analytical synchrotron external shock models of gamma-ray bursts","authors":"He Gao ,&nbsp;Wei-Hua Lei ,&nbsp;Yuan-Chuan Zou ,&nbsp;Xue-Feng Wu ,&nbsp;Bing Zhang","doi":"10.1016/j.newar.2013.10.001","DOIUrl":"10.1016/j.newar.2013.10.001","url":null,"abstract":"<div><p><span>Gamma-ray bursts are most luminous explosions in the universe. Their ejecta are believed to move towards Earth with a relativistic speed. The interaction between this “relativistic jet” and a circumburst medium drives a pair of (forward and reverse) shocks. The electrons accelerated in these shocks radiate </span>synchrotron<span><span> emission to power the broad-band afterglow of GRBs. The external shock theory is an elegant theory, since it invokes a limit number of model parameters, and has well predicted spectral and temporal properties. On the other hand, depending on many factors (e.g. the energy content, ambient density profile, </span>collimation<span> of the ejecta, forward vs. reverse shock dynamics, and synchrotron spectral regimes), there is a wide variety of the models. These models have distinct predictions on the afterglow decaying indices, the spectral indices, and the relations between them (the so-called “closure relations”), which have been widely used to interpret the rich multi-wavelength afterglow observations. This review article provides a complete reference of all the analytical synchrotron external shock afterglow models by deriving the temporal and spectral indices of all the models in all spectral regimes, including some regimes that have not been published before. The review article is designated to serve as a useful tool for afterglow observers to quickly identify relevant models to interpret their data. The limitations of the analytical models are reviewed, with a list of situations summarized when numerical treatments are needed.</span></span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"57 6","pages":"Pages 141-190"},"PeriodicalIF":6.0,"publicationDate":"2013-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2013.10.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72716294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"The stochastic nature of stellar population modelling","authors":"Miguel Cerviño","doi":"10.1016/j.newar.2013.09.001","DOIUrl":"10.1016/j.newar.2013.09.001","url":null,"abstract":"<div><p>Since the early 1970s, stellar population<span> modelling has been one of the basic tools for understanding the physics<span> of unresolved systems from observation of their integrated light. Models allow us to relate the integrated spectra (or colours) of a system with the evolutionary status of the stars of which it is composed and hence to infer how the system has evolved from its formation to its present stage. On average, observational data follow model predictions, but with some scatter, so that systems with the same physical parameters (age, metallicity, total mass) produce a variety of integrated spectra. The fewer the stars in a system, the larger is the scatter. Such scatter is sometimes much larger than the observational errors, reflecting its physical nature. This situation has led to the development in recent years (especially since 2010) of Monte Carlo models of stellar populations. Some authors have proposed that such models are more realistic than state-of-the-art standard synthesis codes that produce the mean of the distribution of Monte Carlo models.</span></span></p><p>In this review, I show that these two modelling strategies are actually equivalent, and that they are not in opposition to each other. They are just different ways of describing the probability distributions intrinsic in the very modelling of stellar populations. I show the advantages and limitations of each strategy and how they complement each other. I also show the implications of the probabilistic description of stellar populations in the application of models to observational data obtained with high-resolution observational facilities. Finally, I outline some possible developments that could be realized in stellar population modelling in the near future.</p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"57 5","pages":"Pages 123-139"},"PeriodicalIF":6.0,"publicationDate":"2013-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2013.09.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72496847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Galactic Archaeology: The dwarfs that survived and perished","authors":"Vasily Belokurov","doi":"10.1016/j.newar.2013.07.001","DOIUrl":"10.1016/j.newar.2013.07.001","url":null,"abstract":"<div><p><span>From the archaeological point of view, the local dwarf galaxies are unique objects in which the imprint of the conditions that shaped the early structure formation can be studied today at high resolution. Over the last decade, this new window into the high redshift Universe has started to be exploited using deep wide-field imaging, high resolution spectroscopy and cutting edge N-body and hydro-dynamical simulations. We review the recent advances in the observational studies of the </span>Milky Way dwarf galaxies, with the aim to understand the properties of the population as a whole and to assist an objective comparison between the models and the data.</p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"57 3","pages":"Pages 100-121"},"PeriodicalIF":6.0,"publicationDate":"2013-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2013.07.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84022678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Internal kinematics and dynamical models of dwarf spheroidal galaxies around the Milky Way","authors":"Giuseppina Battaglia ,&nbsp;Amina Helmi ,&nbsp;Maarten Breddels","doi":"10.1016/j.newar.2013.05.003","DOIUrl":"10.1016/j.newar.2013.05.003","url":null,"abstract":"<div><p>We review our current understanding of the internal dynamical properties of the dwarf spheroidal galaxies<span> surrounding the Milky Way. These are the most dark matter dominated galaxies, and as such may be considered ideal laboratories to test the current concordance cosmological model, and in particular provide constraints on the nature of the dominant form of dark matter. We discuss the latest observations of the kinematics of stars in these systems, and how these may be used to derive their mass distribution. We tour through the various dynamical techniques used, with emphasis on the complementarity and limitations, and discuss what the results imply also in the context of cosmological models. Finally we provide an outlook on exciting developments in this field.</span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"57 3","pages":"Pages 52-79"},"PeriodicalIF":6.0,"publicationDate":"2013-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2013.05.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89813426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}