Download or read book The Effect of Environment on the Formation and Evolution of Galaxies in the Distant Universe written by Robert W. Chuter and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis I primarily use the UKIDSS Ultra-Deep Survey (UDS) to investigate the effect environment has on galaxies across the redshift range 0.25 z
Download or read book Galaxy Formation and Evolution written by Houjun Mo and published by Cambridge University Press. This book was released on 2010-05-20 with total page 841 pages. Available in PDF, EPUB and Kindle. Book excerpt: A coherent introduction for researchers in astronomy, particle physics, and cosmology on the formation and evolution of galaxies.
Download or read book Nearly Normal Galaxies written by Sandra M. Faber and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is sometimes said that astronomy is the crossroads of physics. In the same spirit, it can forcefully be argued that galaxies are the crossroads of astronomy. Internal pro ces ses within galaxies involve all of the fundamental components of astrophysics: stellar evolution, star formation, low-density astrophysics, dynamics, hydrodynamics, and high-energy astrophysics. Indeed, one can hardly name an observational datum in any wavelength range on any kind of celestial object that does not provide a useful clue to galaxy formation and evolution. Although internal processes in galaxies until recently occupied most of our attention, we now know that it is also vital to relate galaxies to their environment. How galaxies congregate in larger structures and are in turn influenced by them are crucial questions for galactic evolution. On a grander level we have also come to regard galaxies as the basic building blocks of the universe, the basic units whereby the large scale structure of the universe is apprehended and quantified. On a grander level still, we also believe strongly that galaxies are the direct descendents of early density irregularities in the Big Bang. Galaxy properties are now viewed as providing a crucial constraint on the physics of the Big Bang and a vital link between the macroscopic and microscopic structure of the universe.
Download or read book Introduction to Galaxy Formation and Evolution written by Andrea Cimatti and published by Cambridge University Press. This book was released on 2019-10-17 with total page 587 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive examination of nearly fourteen billion years of galaxy formation and evolution, from primordial gas to present-day galaxies.
Download or read book Galaxies written by Francoise Combes and published by John Wiley & Sons. This book was released on 2021-04-27 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Galaxies are vast ensembles of stars, gas and dust, embedded in dark matter halos. They are the basic building blocks of the Universe, gathered in groups, clusters and super-clusters. They exist in many forms, either as spheroids or disks. Classifications, such as the Hubble sequence (based on mass concentration and gas fraction) and the colormagnitude diagram (which separates a blue cloud from a red sequence) help to understand their formation and evolution. Galaxies spend a large part of their lives in the blue cloud, forming stars as spiral or dwarf galaxies. Then, via a mechanism that is still unclear, they stop forming stars and quietly end in the red sequence, as spheroids. This transformation may be due to galaxy interactions, or because of the feedback of active nuclei, through the energy released by their central super-massive black holes. These mechanisms could explain the history of cosmic star formation, the rate of which was far greater in the first half of the Universes life. Galaxies delves into all of these surrounding subjects in six chapters written by dedicated, specialist astronomers and researchers in the field, from their numerical simulations to their evolutions.
Download or read book The Formation and Evolution of Galaxies as a Function of Environment written by Yara Lorena Jaffe and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astronomy and Astrophysics in the New Millennium written by National Research Council and published by National Academies Press. This book was released on 2002-02-07 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: In preparing the report, Astronomy and Astrophysics in the New Millenium , the AASC made use of a series of panel reports that address various aspects of ground- and space-based astronomy and astrophysics. These reports provide in-depth technical detail. Astronomy and Astrophysics in the New Millenium: An Overview summarizes the science goals and recommended initiatives in a short, richly illustrated, non-technical booklet.
Download or read book Galaxies in the Distant Universe written by and published by . This book was released on 2010 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Cosmic Evolution written by Eric J. Chaisson and published by Harvard University Press. This book was released on 2001-02-16 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chaisson addresses some of the most basic issues we can contemplate: the origin of matter and the origin of life, and the ways matter, life, and radiation interact and change with time. He designs for us an expansive yet intricate model depicting the origin and evolution of all material structures.
Download or read book Environment and the Formation of Galaxies written by Ignacio Ferreras and published by . This book was released on 2011-07-07 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Galaxy Transformation Under Extreme Conditions written by Brian Clark Lemaux and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes research performed in the field of observational astrophysics as part of the Observations of Redshift Evolution in Large Scale Environment (ORELSE) survey. The general motivation of the research presented in this dissertation is to investigate the processes responsible for the evolution of galaxies in a wide range of physical conditions over cosmic time. Throughout this dissertation, galaxy populations will be considered in the very nearby universe (i.e., within one billion light years from Earth), the middle-aged universe (i.e., eight billion years ago), and in the very early universe (i.e., just one billion years after the beginning of the universe). In each chapter I present unique data from observations taken and analyzed specifically for the ORELSE survey. In the first part of this dissertation I describe the context, aims, and current state of the ORELSE survey. The studies presented in this dissertation span a large range of galaxy samples and investigate a variety of different astrophysical phenomena. As all of these studies fall under the context of galaxy evolution, these initial sections will set the framework for the variety of studies presented in this thesis. In the second part of this dissertation I present four studies undertaken to investigate various aspects of galaxy evolution. The first of these studies is an investigation of a large population of very distant galaxies detected in one of the ORELSE fields. The survey in this field represents the deepest survey of a particular kind of very distant galaxy population known as Lyman[alpha] Emitter (LAEs). The number of LAEs found in this survey far exceeded expectations for such galaxies and are shown to be in excess of every other survey of similar galaxies at similar distances. This result has important consequences for galaxy evolution studies, as it suggests that faint LAEs may be much more numerous than previously thought. This work also has important consequences for a process in the early universe known as reionization, which is the subject of much debate amongst astronomers. The second and third of these studies are investigations using near-infrared spectroscopy of X-ray bright and red galaxies that exhibit optical spectra with prominent emission features. These studies are the first systematic investigations of both galaxy populations in the middle-aged universe using near-infrared spectroscopy. In both studies I conclude the dominant mechanism giving rise to optical emission line features are processes associated with the presence of an Active Galactic Nuclei (AGN) rather than normal star formation. This result has important consequences for galaxy evolutionary scenarios, as the two processes are typically difficult to separate observationally and are thought to be related. The final study in this presentation is a full investigation of the processes driving galaxy evolution in one of the ORELSE fields, the Cl1604 supercluster. In this study I present the wealth of astronomical observations available to the ORELSE survey on the member galaxies of this supercluster. Several transitional populations of galaxies are detected in the supercluster environment, and their properties are analyzed in the context of galaxy evolution. Processing of the galaxy population is found to be significant in both the densest environments in the supercluster and the lower-density regions. One of the major conclusions of this work relates to the efficiency of these transformative processes and the global environment in which a galaxy resides. I present evidence for a process termed "dynamical downsizing", in which efficient transforming of galaxies occurs earliest in structures of galaxies that are observed to be relaxed (i.e., virialized) in their dynamics.
Download or read book Assessment of Options for Extending the Life of the Hubble Space Telescope written by National Research Council and published by National Academies Press. This book was released on 2005-03-28 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Hubble Space Telescope (HST) has operated continuously since 1990. During that time, four space shuttle-based service missions were launched, three of which added major observational capabilities. A fifth â€" SM-4 â€" was intended to replace key telescope systems and install two new instruments. The loss of the space shuttle Columbia, however, resulted in a decision by NASA not to pursue the SM-4 mission leading to a likely end of Hubble's useful life in 2007-2008. This situation resulted in an unprecedented outcry from scientists and the public. As a result, NASA began to explore and develop a robotic servicing mission; and Congress directed NASA to request a study from the National Research Council (NRC) of the robotic and shuttle servicing options for extending the life of Hubble. This report presents an assessment of those two options. It provides an examination of the contributions made by Hubble and those likely as the result of a servicing mission, and a comparative analysis of the potential risk of the two options for servicing Hubble. The study concludes that the Shuttle option would be the most effective one for prolonging Hubble's productive life.
Download or read book Feedback and Environmental Effect on Star Formation in Galaxies written by Taro Sato and published by ProQuest. This book was released on 2007 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent studies of galaxy evolution and formation have shown that both environment and gaseous "feedback" process are critical factors that give rise to the observed variety and richness in galaxy populations. This thesis presents research in these two seemingly disparate aspects of galaxy formation. One deals with a detailed study of the star-forming galaxy population in z = 0.4 galaxy cluster Abell 851, which describes how they may be the key population at an intermediate phase of environmentally-driven evolution, causing the Butcher-Oemler effect. The other is a study of host galaxies of gaseous outflows which are drawn from a large-scale galaxy survey. The census shows that starburst-driven outflows are ubiquitous in the galaxies in transition, suggesting the importance of feedback-driven evolution. We speculate on how these factors might play synergetic or even integral roles in transforming the star-forming property of galaxy, and propose a few directions of research that may help elucidate the significance of feedback and environment in galaxy formation and evolution.
Download or read book Physics in a New Era written by National Research Council and published by National Academies Press. This book was released on 2001-07-15 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics at the beginning of the twenty-first century has reached new levels of accomplishment and impact in a society and nation that are changing rapidly. Accomplishments have led us into the information age and fueled broad technological and economic development. The pace of discovery is quickening and stronger links with other fields such as the biological sciences are being developed. The intellectual reach has never been greater, and the questions being asked are more ambitious than ever before. Physics in a New Era is the final report of the NRC's six-volume decadal physics survey. The book reviews the frontiers of physics research, examines the role of physics in our society, and makes recommendations designed to strengthen physics and its ability to serve important needs such as national security, the economy, information technology, and education.
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 Intrinsic Characteristics of Galaxies in the Distant Universe written by Bomee Lee and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the major questions in observational cosmology is how galaxies formed and how they evolved. In particular, understanding the assembly history of galaxies at the peak epoch of the star formation activity, z=1-3, is a key to understanding the whole picture of the Universe, but remains uncertain. Galaxies with various physical properties and morphologies have different formation and evolution histories. As such, we seek insight into galaxy formation and evolution at z=1-3 using galaxies selected from Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) in this dissertation. First, we investigate the relationship between spectral types and morphologies using various parametric diagnostics and visual inspections. Our sample clearly separates into massive, red, and passive galaxies versus less massive, blue, and star forming ones, and this dichotomy correlates very well with the galaxies' morphological properties. From this study, we suggest that the backbone of the Hubble sequence was already in place at z~2. Second, we explore how the choice of star formation histories affects estimating galaxy properties by adopting flexible star formation history models to the fitting of galaxy's spectrum. The estimation of galaxy properties is improved using CANDELS observations providing unprecedented coverage and depths, and using an advanced fitting technique. We find that galaxy properties, particularly age and star formation rate, are sensitive to the choice of star formation histories. We also find that using different best-fit star formation histories leads to significantly different results on the main sequence of star formation. Our results demonstrate that using the best-fit star formation history for each galaxy is more appropriate way than using one analytic model for all galaxy types. Third, with accurately measured stellar mass and star formation rate, we study characteristics of galaxies on, above, and below the main sequence. We find that distinct morphological differences are shown among different galaxy populations using various diagnostics. On average, as star formation activities decrease, galaxies become denser having smaller sizes and steeper light profiles at all explored redshifts. We also show that the compact morphology is not necessary to precede a passivity of star formation. Our results do not support that gas-rich merging is the key driver to assemble very compact, massive early-type galaxies observed at z~2. Instead, we suggest that compact galaxies simply assemble at very early times and evolve through in situ star formation to form compact massive, quiescent galaxies without significant merging events.
