Download or read book Mass Distribution of Hot Stellar Systems written by Xiaoan Wu and published by . This book was released on 2007 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mass distribution of hot stellar systems is hard to measure because they do not contain gas or star disks, and because there is a degeneracy between the overall mass distribution and the distribution function of the observable particles. Assuming that the potential is spherical, we describe a maximum-likelihood nonparametric method to utilize to the full extent available kinematic data, which is applied to an elliptical galaxy (M87), three dwarf spheroidal galaxies (Draco, Ursa Minor and Fornax) and a globular cluster (o Centauri). For M87, the mass within 32 kpc is (2:4 +/- 0:6) x 1012 M ⊙ , and the exponent of the density profile rho ∝ r -alpha in the range 10 - 100 kpc is alpha = 1:6 +/- 0:4. The energy distribution suggests a few kinematically distinct groups of globular clusters. For dwarf spheroidal galaxies, our models naturally produce the so-called "extra-tidal extensions", which had previously been suggested as evidence of tidal stripping. The average V-band mass-to-light ratio is 400 +/- 80M ⊙ =LV, ⊙ within 0:75 kpc for Draco, 580+140-100 M ⊙ =V, ⊙ within 1:1 kpc for Ursa Minor and 25+7-5 M ⊙ =LV, ⊙ within 2:5 kpc for Fornax. We do not find that anisotropy contributes substantially to the high mass-to-light ratios in these dSph galaxies. For o Centauri, we derive an averaged (V -band) mass-to-light ratio Gamma = 2:96 +/- 0:10 M ⊙ /L ⊙ . Moreover, we find no evidence that the even part of the DF is dependent on total angular momentum; that is, two-integral models in which the DF depends on energy and the z'-component of angular momentum are sufficient to fit the data.
Download or read book On the Distribution of High Energy Stars in Spherical Stellar Systems written by RICHARD W. MICHIE and published by . This book was released on 1962 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: A distribution function f(r, v, u;t) for isolated spherical stellar systems is obtained from the Boltzmann equation with encounters described by the Fokker-Planck equation. The distribution function is believed to correspond rather closely to actual stellar systems since it is obtained from the Boltzmann equation, the potential is obtained from Poisson's equation, and the stellar orbits are not assumed to be isotropic everywhere but rather are more radial at greater distances from the center. The importance of a careful analysis in the region of phase space at and near the energy of escape is emphasized. In this region, it is shown that the velocity space flux vector is constant, and it is this constancy which allows a solution for f. The distribution of high energy stars is depopulated for (1) those stars whose mass is small compared to the average stellar mass, (2) regions close to the center of the system, and (3) large values of the model parameter C. It is proposed that the method of analysis presented may be used for obtaining a distribution function for rotating stellar systems. (Author).
Download or read book A Question and Answer Guide to Astronomy written by Pierre-Yves Bely and published by Cambridge University Press. This book was released on 2017-03-23 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains 250 questions and answers about astronomy, particular for the amateur astronomer.
Download or read book Comparison of the Large scale Structure of the Galactic System with that of Other Stellar Systems written by Nancy Grace Roman and published by . This book was released on 1958 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Stellar Systems written by K. F. Ogorodnikov and published by Elsevier. This book was released on 2013-10-22 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics of Stellar Systems discusses the basic principles that support stellar dynamics. The book is comprised of 10 chapters that present the general principles on which it is based and how the modern conceptions of motions in stellar systems can be derived. The text first discusses the fundamentals concepts of stellar statistics, and then proceeds to detailing the kinematics of stellar systems. The next chapter covers the elementary theory of galactic rotation. Next, the book tackles the irregular forces in stellar systems. Chapter V talks about the statistical stellar dynamics neglecting encounters, while Chapter VI deals with the regular orbit of the stars. In the eighth chapter, the text tackles the problem of local dynamics. The remaining chapters deal with the dynamics of centroids, spherical stellar systems, and rotating stellar systems. The book will be of great interest to researchers and practitioners of disciplines that deal with celestial bodies, such as astronomy and astrophysics.
Download or read book Galactic Dynamics written by James Binney and published by Princeton University Press. This book was released on 2011-10-30 with total page 902 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since it was first published in 1987, Galactic Dynamics has become the most widely used advanced textbook on the structure and dynamics of galaxies and one of the most cited references in astrophysics. Now, in this extensively revised and updated edition, James Binney and Scott Tremaine describe the dramatic recent advances in this subject, making Galactic Dynamics the most authoritative introduction to galactic astrophysics available to advanced undergraduate students, graduate students, and researchers. Every part of the book has been thoroughly overhauled, and many sections have been completely rewritten. Many new topics are covered, including N-body simulation methods, black holes in stellar systems, linear stability and response theory, and galaxy formation in the cosmological context. Binney and Tremaine, two of the world's leading astrophysicists, use the tools of theoretical physics to describe how galaxies and other stellar systems work, succinctly and lucidly explaining theoretical principles and their applications to observational phenomena. They provide readers with an understanding of stellar dynamics at the level needed to reach the frontiers of the subject. This new edition of the classic text is the definitive introduction to the field. ? A complete revision and update of one of the most cited references in astrophysics Provides a comprehensive description of the dynamical structure and evolution of galaxies and other stellar systems Serves as both a graduate textbook and a resource for researchers Includes 20 color illustrations, 205 figures, and more than 200 problems Covers the gravitational N-body problem, hierarchical galaxy formation, galaxy mergers, dark matter, spiral structure, numerical simulations, orbits and chaos, equilibrium and stability of stellar systems, evolution of binary stars and star clusters, and much more Companion volume to Galactic Astronomy, the definitive book on the phenomenology of galaxies and star clusters
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mass Loss from Stars and the Evolution of Stellar Clusters written by Alex de Koter and published by . This book was released on 2008 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In the spring of 2006 a four day international workshop was held in Lunteren, The Netherlands, in honor of the formal retirement of Prof. Henny Lamers. These proceedings provide a comprehensive overview of mass loss in massive stars and of the dynamical fate of clusters. The dynamical evolution of clusters is affected by stellar winds, mass loss outbursts and supernova explosions as well as by the loss of stars in dynamical interactions, thus linking the two central themes of the workshop. It is becoming clear that mass loss by radiation pressure on spectral lines is not only at work in normal O, B, and A stars but also in Luminous Blue Variables and Wolf-Rayet stars. The importance of these line-driven winds relative to outbursts in the Luminous Blue Variable phase of evolution is under debate. A central issue in this discussion is the importance of small and possibly large scale structure in stellar winds and its implications for the measured mass loss rates. These proceedings report on progress establishing wind properties, on theoretical predictions of mass loss and wind structure as a function of stellar properties, and on the effects of mass loss on the evolution of massive stars. As a result of dynamical interactions, clusters may dissolve completely over time. Observational studies of cluster dissolution timescales as a function of cluster formation history and cluster and environmental properties, are at the focus of cluster studies in the last decade. A key topic discussed in this book is whether the old globular clusters we observe today were once similar to present-day massive young clusters. The mass function of the two types of clusters is observed to be different. Is this a result of dynamical evoltuion or were the mass functions different at formation? The 12 invited reviews, 18 contributed talks, 48 poster papers, and two discussion sessions combine to provide and in-depth assessment of both observational and theoretical issues. The book is suitable for researchers and graduate students interested in stellar astrophysics and cluster dynamics."--Provided by publisher.
Download or read book Planets Stars and Stellar Systems written by Gerard Gilmore and published by Springer. This book was released on 2013-02-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is volume 5 of Planets, Stars and Stellar Systems, a six-volume compendium of modern astronomical research, covering subjects of key interest to the main fields of contemporary astronomy. This volume on “Galactic Structure and Stellar Populations”, edited by Gerard F. Gilmore, presents accessible review chapters on Stellar Populations, Chemical Abundances as Population Tracers, Metal-Poor Stars and the Chemical Enrichment of the Universe, The Stellar and Sub-Stellar Initial Mass Function of Simple and Composite Populations, The Galactic Nucleus, The Galactic Bulge, Open Clusters and Their Role in the Galaxy, Star Counts and the Nature of Galactic Thick Disk, The Infrared Galaxy, Interstellar PAHs and Dust, Galactic Neutral Hydrogen, High-Velocity Clouds, Magnetic Fields in Galaxies, Astrophysics of Galactic Charged Cosmic Rays, Gamma-Ray Emission of Supernova Remnants and the Origin of Galactic Cosmic Rays, Galactic Distance Scales, Globular Cluster Dynamical Evolution, Dynamics of Disks and Warps, Mass Distribution and Rotation Curve in the Galaxy, Dark Matter in the Galactic Dwarf Spheroidal Satellites, and History of Dark Matter in Galaxies. All chapters of the handbook were written by practicing professionals. They include sufficient background material and references to the current literature to allow readers to learn enough about a specialty within astronomy, astrophysics and cosmology to get started on their own practical research projects. In the spirit of the series Stars and Stellar Systems published by Chicago University Press in the 1960s and 1970s, each chapter of Planets, Stars and Stellar Systems can stand on its own as a fundamental review of its respective sub-discipline, and each volume can be used as a textbook or recommended reference work for advanced undergraduate or postgraduate courses. Advanced students and professional astronomers in their roles as both lecturers and researchers will welcome Planets, Stars and Stellar Systems as a comprehensive and pedagogical reference work on astronomy, astrophysics and cosmology.
Download or read book 14th Cambridge Workshop on Cool Stars Stellar Systems and the Sun written by Gerard Van Belle and published by . This book was released on 2008 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Cool Stars 14 (CS14) was held in Pasadena, 5-10 November 2006, and was jointly hosted by the Spitzer Science Center and the Michelson Science Center. CS14 also doubled as the 2006 Spitzer Science Center November Workshop. Topics that were central to the previous Cool Stars Meetings -- stellar activity indicators, the solar-stellar connection, PMS stars and stellar evolution, brown dwarfs, and helio-and asteroseismology -- continued to be high on the agenda for CS14. Enhanced emphasis was also placed on topics such as mid-IR observations (debris disk evolution; protostar formation) and high-angular resolution observations (PMS disk imaging, PMS binary orbits, future space astrometry missions). Main plenary session topics included Helioseismology and Abundances, Star Formation (Cores to Disks), Brown Dwarfs, Solar/Stellar Magnetic Fields, Testing Stellar Evolutionary Models, Extrasolar Planets, and Stellar Winds an Spins: From Birth Through the Main Sequence. Additionally, nine splinter sessions examined the following topics in detail: Spectral Diagnostics of Hot Plasma from Cool Stars, The Formation of Low-Mass Protostars and Proto-BDs, Mining the Next Generation of Surveys for Cool Star Science, Stellar Ages, Disks around Cool Stars and Bds, Cool Stars in Hot Places, Habitability and Life on Planets around Cool Stars, Sub-Stellar Twins: Binarity in Bds, and Coronal Structure of PMS Stars. The presentations of the seven main sessions are detailed with reviews in this volume, in addition to summaries of the nine splinter sessions. The book is suitable for researchers and graduate students interested in the astrophysics of cool stars and the sun, including abundances, magnetohydrodynamics, circumstellar disks, stellar rotation, pulsation and mass loss." -- publisher's website.
Download or read book Researches on the Evolution of the Stellar Systems Vol 2 written by Thomas J. J. See and published by . This book was released on 2016-10-22 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Origins of the Earth Moon and Life written by Akio Makishima and published by Elsevier. This book was released on 2017-01-27 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Origins of the Earth, Moon, and Life: An Interdisciplinary Approach presents state-of-the-art knowledge that is based on theories, experiments, observations, calculations, and analytical data from five astro-sciences, astronomy, astrobiology, astrogeology, astrophysics, and cosmochemistry. Beginning with the origin of elements, and moving on to cover the formation of the early Solar System, the giant impact model of the Earth and Moon, the oldest records of life, and the possibility of life on other planets in the Solar System, this interdisciplinary reference provides a complex understanding of the planets and the formation of life. Synthesizing concepts from all branches of astro-sciences into one, the book is a valuable reference for researchers in astrogeology, astrophysics, cosmochemistry, astrobiology, astronomy, and other space science fields, helping users better understand the intersection of these sciences. Includes extensive figures and tables to enhance key concepts Uses callout boxes throughout to provide context and deeper explanations Presents up-to-date information on the universe, stars, planets, moons, and life in the solar system Combines knowledge from the fields of astrogeology, astrophysics, cosmochemistry, astrobiology, and astronomy, helping readers understand the origins of the Earth, the moon, and life in our solar system
Download or read book Researches on the Evolution of the Stellar Systems written by Thomas Jefferson Jackson See and published by . This book was released on 1896 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Large Scale Structures in the Universe written by A. C. Fabian and published by . This book was released on 1987 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Star Formation Rates of Galaxies written by Andreas Zezas and published by Cambridge University Press. This book was released on 2021-04-29 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Star-formation is one of the key processes that shape the current state and evolution of galaxies. This volume provides a comprehensive presentation of the different methods used to measure the intensity of recent or on-going star-forming activity in galaxies, discussing their advantages and complications in detail. It includes a thorough overview of the theoretical underpinnings of star-formation rate indicators, including topics such as stellar evolution and stellar spectra, the stellar initial mass function, and the physical conditions in the interstellar medium. The authors bring together in one place detailed and comparative discussions of traditional and new star-formation rate indicators, star-formation rate measurements in different spatial scales, and comparisons of star-formation rate indicators probing different stellar populations, along with the corresponding theoretical background. This is a useful reference for students and researchers working in the field of extragalactic astrophysics and studying star-formation in local and higher-redshift galaxies.
Download or read book Fundamentals of Galaxy Dynamics Formation and Evolution written by Ignacio Ferreras and published by UCL Press. This book was released on 2019-04-02 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Galaxies, along with their underlying dark matter halos, constitute the building blocks of structure in the Universe. Of all fundamental forces, gravity is the dominant one that drives the evolution of structures from small density seeds at early times to the galaxies we see today. The interactions among myriads of stars, or dark matter particles, in a gravitating structure produce a system with fascinating connotations to thermodynamics, with some analogies and some fundamental differences. Ignacio Ferreras presents a concise introduction to extragalactic astrophysics, with emphasis on stellar dynamics, and the growth of density fluctuations in an expanding Universe. Additional chapters are devoted to smaller systems (stellar clusters) and larger ones (galaxy clusters). Fundamentals of Galaxy Dynamics, Formation and Evolution is written for advanced undergraduates and beginning postgraduate students, providing a useful tool to get up to speed in a starting research career. Some of the derivations for the most important results are presented in detail to enable students appreciate the beauty of maths as a tool to understand the workings of galaxies. Each chapter includes a set of problems to help the student advance with the material.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
