Download or read book The Connection Between Dark and Baryonic Matter in the Process of Galaxy Formation written by Sebastian Trujillo and published by . This book was released on 2014 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current galaxy formation theory still struggles to explain many essential galaxy properties. This thesis addresses these problems in the context of the interplay between baryons and dark matter in the concordance cosmological model. In the first part, we investigate galaxy abundance and scaling relations using a compilation of observational data along with large-scale cosmological simulations of dark matter (DM). We find that standard cosmological model, in conjunction with halo abundance matching (HAM) and simple dynamical corrections, fits all basic statistics of galaxies more than the Large Magellanic Cloud (LMC). This zero-parameter model predicts the observed luminosity-velocity relation of early- and late-type galaxies, as well as the clustering of bright galaxies and the observed abundance of galaxies as function of circular velocity. However, we find that all DM halos more massive than the LMC are much more abundant than galaxies they host. Motivated by the model's shortcomings, in the second part we study the effect of baryons on galaxy formation using numerical simulations that include gas physics. We implement a model of star formation (SF) and stellar feedback based directly on observations of star-forming regions, where stellar feedback from massive stars includes radiation pressure, photoheating, supernovae, and stellar winds. We find that stellar radiation has a strong effect at z > 1, where it efficiently suppresses SF by dispersing cold and dense gas, preventing runaway growth of the stellar component, and yielding rising SF histories that reproduce many observations. Stellar feedback produces bulgeless discs with rotation curves and baryon fractions in excellent agreement with data. Feedback-driven blowouts reduce the central DM density of a dwarf, reliving tension between [lambda]CDM and observations. Based on these results, we begin to characterize the baryon cycle of galaxies and its imprint on studies of the circumgalactic medium (CGM). We find that feedback has a large impact on the exchange of gas and metals between the galaxy and the halo. This is evidenced in the spatial distribution of various gas phases and in the kinematics of accretion and outflows. We conclude that synergy between simulations and absorption-line studies is essential for disentangling the physics of galaxy formation in the context of [lambda]CDM.
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 How Dark Matter Created Dark Energy and the Sun written by Jerome Drexler and published by Universal-Publishers. This book was released on 2004 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Through use of a lecture-slide format, this book presents an astrophysics detective story that chronicles Jerome Drexler's literature search for astronomical clues and evidence to unveil the nature of dark matter. There are a number of mysteries in astrophysics and cosmology that have remained unsolved for decades. What is dark matter? How exactly are stars created? In 1998, it was determined from supernova studies that the expansion of the Universe was accelerating, thereby creating the mystery of dark energy. Astrophysicists have developed mutually exclusive, single-phenomenon theories for each of these three phenomena, but not a unified theory for all three of them. The author's original goal was to identify dark matter, a decades-old mystery. In the process, he developed a new theory for dark matter and illuminated the nature of dark energy and the process of Sun formation. Since dark matter may have been instrumental in the creation of galaxies and stars, the author decided to test his new dark matter theory on the formation of the Sun. The results were very encouraging. He next sought a possible link between dark matter and the accelerating expansion of the Universe, which is attributed to the mysterious dark energy. Using his dark matter theory and the laws of physics, the author explained the accelerating expansion of the Universe in a plausible manner. This book chronicles the author's search for a unified astrophysical theory and how it finally evolved.
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 Connecting Quarks with the Cosmos written by National Research Council and published by National Academies Press. This book was released on 2003-03-12 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances made by physicists in understanding matter, space, and time and by astronomers in understanding the universe as a whole have closely intertwined the question being asked about the universe at its two extremesâ€"the very large and the very small. This report identifies 11 key questions that have a good chance to be answered in the next decade. It urges that a new research strategy be created that brings to bear the techniques of both astronomy and sub-atomic physics in a cross-disciplinary way to address these questions. The report presents seven recommendations to facilitate the necessary research and development coordination. These recommendations identify key priorities for future scientific projects critical for realizing these scientific opportunities.
Download or read book Baryonic Dark Matter written by D. Lynden-Bell and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The visible universe is a small perturbation on the material universe. Zwicky and Sinclair Smith in the 1930s gave evidence of invisible mass in the Coma and Virgo Clusters of Galaxies. Better optical data has only served to confound their critics and the X-ray data confirms that the gravitational potentials are many times larger than those predicted on the basis of the observed stars. Dynamical analyses of individual galaxies have found that significant extra mass is needed to explain their rotational velocities. On much larger scales, tens of megaparsecs, there is suggestive evidence that there is even more mass per unit luminosity. What is this non-luminous stuff of which the universe is made'? How much of it is there? Need there be only one kind of stuff? There are three basic possi bili ties:- all of it is ordinary (baryonic) matter, all of it is some other kind of (non-baryonic) matter, or some of it is baryonic and some is non-baryonic.
Download or read book In Search of Dark Matter written by Ken Freeman and published by Springer Science & Business Media. This book was released on 2006-08-25 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written for the educated non-scientist and scientist alike, it spans a variety of scientific disciplines, from observational astronomy to particle physics. Concepts that the reader will encounter along the way are at the cutting edge of scientific research. However the themes are explained in such a way that no prior understanding of science beyond a high school education is necessary.
Download or read book A Philosophical Approach to MOND written by David Merritt and published by Cambridge University Press. This book was released on 2020-04-30 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dark matter is a fundamental component of the standard cosmological model, but in spite of four decades of increasingly sensitive searches, no-one has yet detected a single dark-matter particle in the laboratory. An alternative cosmological paradigm exists: MOND (Modified Newtonian Dynamics). Observations explained in the standard model by postulating dark matter are described in MOND by proposing a modification of Newton's laws of motion. Both MOND and the standard model have had successes and failures – but only MOND has repeatedly predicted observational facts in advance of their discovery. In this volume, David Merritt outlines why such predictions are considered by many philosophers of science to be the 'gold standard' when it comes to judging a theory's validity. In a world where the standard model receives most attention, the author applies criteria from the philosophy of science to assess, in a systematic way, the viability of this alternative cosmological paradigm.
Download or read book The Dark Matter Problem in Rotationally Supported Galaxies written by Pengfei Li and published by . This book was released on 2020 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: Different lines of evidence suggest that the observed dynamics of galaxies, galaxy clusters, and the Universe as a whole cannot be explained by the visible, baryonic matter when applying the standard laws of Gravity. Two competing solutions have been proposed and hotly debated in the past decades: introduce dark matter (DM) or modify the laws of gravity. In this dissertation, I present a systematic investigation of these two hypothesis using 175 late-type galaxies from the Spitzer Photometry \& Accurate Rotation Curves (SPARC) database. On the DM front, I fit the SPARC rotation curves testing seven different halo profiles. Based on these fits, I explore the correlations between DM halos and stellar disks, and find that the characteristic volume density of DM halos is remarkably constant over 5 decades in galaxy luminosity. This serves as a testing bed for galaxy formation models. Using the correlation between DM halo masses and \hi\ line widths, I measure for the first time the DM halo mass function (HMF). The measured HMF agrees with the prediction of DM-only simulations at intermediate and low halo masses, but differs significantly at high mass end. Finally I compute the effect of adiabatic compression on the DM halos due to the baryonic gravitational potential, and find that compressed halos contribute more to rotation curves, exacerbating the core-cusp problem over the whole range of galaxy masses. On the modified gravity front, I test the statistically established radial acceleration relation (RAR) which indicates a strong link between the baryonic mass distribution and the observed dynamics of galaxies. The vast majority of the SPARC galaxies can be well described by the RAR. The best-fit RAR has an rms scatter of 0.057 dex, comparable to the observational uncertainties on rotation curves. This leaves little room for intrinsic scatter if any. I check the critical acceleration scale in the RAR is universal among late-type galaxies, marking no difference between the RAR and the Modified Newtonian Dynamics. Overall, Modified Newtonian Dynamics can describe disk galaxies with less problems than DM models, but a comprehensive evaluation requires the systematic investigations on galaxy-cluster and cosmological scales.
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 Our Universe Via Drexler Dark Matter written by Jerome Drexler and published by Universal-Publishers. This book was released on 2009 with total page 287 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is different from all other modern cosmology books in several ways. It introduces a cosmologic universe, which is orderly, logical, and systematic. It teaches and explains by illustrating how a variety of cosmic mysteries have been solved. It raises the status of dark matter in the universe by illuminating its roles as the principal source of energy, the principal source of matter in the form of hydrogen and helium, and the principal source of cosmic relationships with the principal cosmic phenomena of the universe. This book simplifies the universe as Nicolaus Copernicus' book simplified the solar system in 1543. With more and more cosmic mysteries being discovered and the slow progress in solving them, cosmologists and astrophysicists must re-train themselves to understand and to utilize the postmodern unified astrophysical cosmology model and to maximize the knowledge derived from the astronomical data. These are the three principal objectives of this book.
Download or read book Modern Cosmology written by Scott Dodelson and published by Academic Press. This book was released on 2003-03-13 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: An advanced text for senior undergraduates, graduate students and physical scientists in fields outside cosmology. This is a self-contained book focusing on the linear theory of the evolution of density perturbations in the universe, and the anisotropiesin the cosmic microwave background.
Download or read book Constraining the Physics of Galaxy Formation and Evolution Using Galaxy Clustering written by Douglas F. Watson and published by . This book was released on 2012 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Matter Dark Matter and Anti Matter written by Alain Mazure and published by Springer Science & Business Media. This book was released on 2011-11-16 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: For over ten years, the dark side of the universe has been headline news. Detailed studies of the rotation of spiral galaxies, and 'mirages' created by clusters of galaxies bending the light from very remote objects, have convinced astronomers of the presence of large quantities of dark (unseen) matter in the cosmos. The most striking fact is that they seem to compromise about 95% of the matter/energy content of the universe. As for ordinary matter, although we are immersed in a sea of dark particles, including primordial neutrinos and photons from fossil cosmological radiation, both we and our environment are made of ordinary, 'baryonic' matter. Authors Mazure and Le Brun present the inventory of matter, baryonic and exotic, and investigating the nature and fate of matter's twin, anti-matter. They show how technological progress has been a result of basic research, in tandem with the evolution of new ideas, and how the combined effect of these advances might help lift the cosmic veil.
Download or read book Formation and Evolution of Galaxies and Large Structures in the Universe written by J. Audouze and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Study Institute, La Plagne, France, March, 1983
Download or read book Dark Matter written by Jean Audouze and published by Atlantica Séguier Frontières. This book was released on 1988 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Galaxy Formation and Mergers with Stars and Massive Black Holes written by Chi-hun Kim and published by Stanford University. This book was released on 2011 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: While mounting observational evidence suggests the coevolution of galaxies and their embedded massive black holes (MBHs), a comprehensive astrophysical understanding which incorporates both galaxies and MBHs has been missing. To tackle the nonlinear processes of galaxy formation, we develop a state-of-the-art numerical framework which self-consistently models the interplay between galactic components: dark matter, gas, stars, and MBHs. Utilizing this physically motivated tool, we present an investigation of a massive star-forming galaxy hosting a slowly growing MBH in a cosmological LCDM simulation. The MBH feedback heats the surrounding gas and locally suppresses star formation in the galactic inner core. In simulations of merging galaxies, the high-resolution adaptive mesh allows us to observe widespread starbursts via shock-induced star formation, and the interplay between the galaxies and their embedding medium. Fast growing MBHs in merging galaxies drive more frequent and powerful jets creating sizable bubbles at the galactic centers. We conclude that the interaction between the interstellar gas, stars and MBHs is critical in understanding the star formation history, black hole accretion history, and cosmological evolution of galaxies. Expanding upon our extensive experience in galactic simulations, we are well poised to apply this tool to other challenging, yet highly rewarding tasks in contemporary astrophysics, such as high-redshift quasar formation.
