Testing Both Modes of Galaxy Formation: A Closer Look at Galaxy Mergers and Gas Accretion
Title | Testing Both Modes of Galaxy Formation: A Closer Look at Galaxy Mergers and Gas Accretion PDF eBook |
Author | Yujin Yang |
Publisher | |
Pages | 476 |
Release | 2008 |
Genre | |
ISBN |
This thesis focuses primarily on how two important processes --- galaxymergers and gas accretion from the surrounding intergalactic medium ---affect the evolution of galaxies. Using post-starburst, or E+A, galaxies as a marker sample that undergoesa rapid transition from gas-rich star-forming galaxies to quiescent, passively-evolving E/S0s, we study what triggers E+A evolution andwhat E+A galaxies will become after the fading of their young stellarpopulation. With high resolution HST WFPC2/ACS imaging, we investigatetheir small and large scale properties, including their detailedmorphologies, bulge fractions, color gradients, scaling relationships, and newly formed star-clusters. 70% of E+A galaxies show disturbancesand tidal features indicating a merger origin and all their propertiesare either consistent with those of E/S0s or, if left to evolve passively, will become like those of early-types. Using cosmological simulations, we study hydrogen and helium gravitationalcooling radiation from gas accretion by young galaxies, finding thatobserving optically thin cooling lines such as HeII 1640 and hydrogenHalpha is critical in understanding the nature of galaxies forming viagas-accretion. To obtain an unbiased sample of Lyman alpha blobs thatwill allow us to follow-up their optically thin Halpha lines in the NIR, we conduct a blind, wide-field, narrow-band imaging survey for Lymanalpha blobs. After searching over 4.82 deg2̂, we discover four blobsthat we spectroscopically confirm to lie at z=2.3. The properties ofthese blobs are diverse: two blobs are X-ray-detected and have broadoptical emission lines (e.g., CIV) characteristic of AGN. The other50\% of blobs are not X-ray or optically-detected as AGN down tosimilar limits. The number density of the four blobs is extremely low,3̃ x 10-̂6 Mpc-̂3, comparable to that of galaxy clusters at similarredshifts. The two X-ray undetected blobs are separated by only70"(550 kpc) and have almost identical redshifts (corresponding to
Galaxy Formation and Mergers with Stars and Massive Black Holes
Title | Galaxy Formation and Mergers with Stars and Massive Black Holes PDF eBook |
Author | Chi-hun Kim |
Publisher | Stanford University |
Pages | 189 |
Release | 2011 |
Genre | |
ISBN |
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.
Galaxy Formation and Evolution
Title | Galaxy Formation and Evolution PDF eBook |
Author | Houjun Mo |
Publisher | Cambridge University Press |
Pages | 841 |
Release | 2010-05-20 |
Genre | Science |
ISBN | 0521857937 |
A coherent introduction for researchers in astronomy, particle physics, and cosmology on the formation and evolution of galaxies.
Galaxy Formation and Mergers with Stars and Massive Black Holes
Title | Galaxy Formation and Mergers with Stars and Massive Black Holes PDF eBook |
Author | Ji-hoon Kim |
Publisher | |
Pages | |
Release | 2011 |
Genre | Galaxies |
ISBN |
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.
Deep Millimeter Surveys: Implications For Galaxy Formation And Evolution
Title | Deep Millimeter Surveys: Implications For Galaxy Formation And Evolution PDF eBook |
Author | David H Hughes |
Publisher | World Scientific |
Pages | 223 |
Release | 2001-10-29 |
Genre | Science |
ISBN | 9814492094 |
The arrival of large submillimeter and millimeter-wave detector arrays opened a new window on galaxy formation and evolution. The major new facilities now being designed or constructed, such as ALMA (MMA) and the Large Millimeter Telescope (LMT), will soon be expanding the horizons even farther.The Conference on “Deep Millimeter Surveys: Implications for Galaxy Formation and Evolution” drew together the major international groups working on submillimeter and millimeter-wave galaxies to discuss their relation to other galaxies both near by and in the early Universe, the role of the LMT and other new facilities in advancing the new field, and the implications of the new results and models for our understanding of galaxy formation and evolution. The resulting compendium of reports on observations, simulations, theory and interpretation, and instrumentation is the first book to present the new millimeter view of the early Universe thoroughly in a single volume.
Liturgie Für Den Evangelischen Militär-Gottesdienst, und Pastoral-Instruktion Für Die Feldprediger Evangelischer Konfession
Title | Liturgie Für Den Evangelischen Militär-Gottesdienst, und Pastoral-Instruktion Für Die Feldprediger Evangelischer Konfession PDF eBook |
Author | |
Publisher | |
Pages | 76 |
Release | 2020-03-09 |
Genre | History |
ISBN | 9780371590867 |
Fundamentals of Galaxy Dynamics, Formation and Evolution
Title | Fundamentals of Galaxy Dynamics, Formation and Evolution PDF eBook |
Author | Ignacio Ferreras |
Publisher | UCL Press |
Pages | 200 |
Release | 2019-04-02 |
Genre | Science |
ISBN | 1911307614 |
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.