1# Library to Find Best eBook for Read
Author : Silvio Lorenzoni
Release : 2012
Genre :
Kind : eBook
Book Rating : /5 ( reviews)
Book Synopsis Star-forming Galaxies in the Epoch of Reionization by : Silvio Lorenzoni
Download or read book Star-forming Galaxies in the Epoch of Reionization written by Silvio Lorenzoni. This book was released on 2012. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Abraham Loeb
Release : 2010-07-19
Genre : Science
Kind : eBook
Book Rating : 066/5 ( reviews)
Book Synopsis How Did the First Stars and Galaxies Form? by : Abraham Loeb
Download or read book How Did the First Stars and Galaxies Form? written by Abraham Loeb. This book was released on 2010-07-19. Available in PDF, EPUB and Kindle. Book excerpt: A concise introduction to cosmology and how light first emerged in the universe Though astrophysicists have developed a theoretical framework for understanding how the first stars and galaxies formed, only now are we able to begin testing those theories with actual observations of the very distant, early universe. We are entering a new and exciting era of discovery that will advance the frontiers of knowledge, and this book couldn't be more timely. It covers all the basic concepts in cosmology, drawing on insights from an astronomer who has pioneered much of this research over the past two decades. Abraham Loeb starts from first principles, tracing the theoretical foundations of cosmology and carefully explaining the physics behind them. Topics include the gravitational growth of perturbations in an expanding universe, the abundance and properties of dark matter halos and galaxies, reionization, the observational methods used to detect the earliest galaxies and probe the diffuse gas between them—and much more. Cosmology seeks to solve the fundamental mystery of our cosmic origins. This book offers a succinct and accessible primer at a time when breathtaking technological advances promise a wealth of new observational data on the first stars and galaxies. Provides a concise introduction to cosmology Covers all the basic concepts Gives an overview of the gravitational growth of perturbations in an expanding universe Explains the process of reionization Describes the observational methods used to detect the earliest galaxies
Author : Andrei Mesinger
Release : 2015-11-28
Genre : Science
Kind : eBook
Book Rating : 57X/5 ( reviews)
Book Synopsis Understanding the Epoch of Cosmic Reionization by : Andrei Mesinger
Download or read book Understanding the Epoch of Cosmic Reionization written by Andrei Mesinger. This book was released on 2015-11-28. Available in PDF, EPUB and Kindle. Book excerpt: The dawn of the first stars, galaxies and black holes signaled a fundamental milestone in our Universe’s evolution: the Epoch of Reionization. The light from these galactic ancestors began spreading out, ionizing virtually every atom in existence. Our Universe transitioned from darkness to light, from cold to hot, from simple and boring to the wondrous cosmic zoo we see around us today. Despite its importance, observations of reionization have been few, and their interpretation has been highly controversial. Fortunately, this is rapidly changing. We will soon enter the "Big Data” era of this mysterious epoch, driven by an upcoming wave of observations with state-of-the-art telescopes as well as new sophisticated analysis tools. The aim of this volume is to summarize the current status and future outlook of the reionization field. We bring together leading experts in many sub-disciplines, highlighting the measurements that will illuminate our understanding of reionization and the cosmic dawn: (i) 21cm interferometry; (ii) high-redshift quasar spectra; (iii) high-redshift galaxy surveys; (iv) primary and secondary anisotropies of the Cosmic Microwave Background; (v) high-resolution studies of the metal content of early galaxies. We seek a roadmap to interpreting the wealth of upcoming observations. What is the best use of limited observational resources? How do we develop theoretical tools tailored for each observation? Ultimately, what will we learn about the epoch of reionization and our galactic ancestors?
Author : Grace Margaret Olivier
Release : 2022
Genre : Dwarf galaxies
Kind : eBook
Book Rating : /5 ( reviews)
Book Synopsis Pre-supernova Stellar Feedback by : Grace Margaret Olivier
Download or read book Pre-supernova Stellar Feedback written by Grace Margaret Olivier. This book was released on 2022. Available in PDF, EPUB and Kindle. Book excerpt: Galaxy formation and evolution are driven by stars and star formation. Star formation is fundamental for shaping the universe as we see it today as part of the cosmic ecosystems encompassing galaxies, yet half of the physics that determines how much gas forms into stars – the stellar feedback (injection of energy and momentum to the surrounding material) half of the tug-of-war between gravity and stellar feedback – have only recently become a focus for observational astronomers. Theoretical explorations of stellar feedback have been extensive for the past four decades and our current understanding of star-forming galaxies comes primarily through extensive modeling and simulations with sub-grid physics prescriptions based on a handful of observations. In order to secure the basis for these sub-grid physics models and expand our understanding of star-formation and the effects of massive stars during all epochs of the universe, more observations of these processes are needed. Observations of star forming regions provide the foundation to anchor simulations and observations of analogues to high-redshift galaxies help determine the sources that reionized the universe and the role stars played in during the Epoch of Reionization. With multiwavelength observations of H ii regions in the Milky Way, I have probed the effects of stellar feedback in dynamics of H ii regions, providing the necessary basis for defining the sub-grid physics in simulations. With multiwavelength observations of nearby galaxies with properties similar to galaxies in the EoR (low mass: 107 M⊙; low metallicity:
Author : Charlotte Mason
Release : 2018
Genre :
Kind : eBook
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Book Synopsis Galaxies at the Epoch of Reionization by : Charlotte Mason
Download or read book Galaxies at the Epoch of Reionization written by Charlotte Mason. This book was released on 2018. Available in PDF, EPUB and Kindle. Book excerpt: The reionization of intergalactic hydrogen in the universe's first billion years was likely driven by the first stars and galaxies, so its history encodes information about their prop- erties. But the timeline of reionization is not well-measured and it is still unclear whether galaxies alone can produce the required ionizing photons. In my thesis I have focused on two ways to use galaxies at our current observational frontiers to constrain reionization and high redshift galaxy evolution. One tool is the UV luminosity function (LF), which traces the evolution of star-forming galaxies and their ionizing photons. Accurately measuring LFs and understanding their evolution are important for understanding the connections between galaxies and their dark matter halos. I developed a simple, but powerful, semi-analytic model for LF evolution assuming star formation is driven by dark matter accretion. This has proved remarkably consistent with observations, and implies the majority of star formation at high redshifts occurs in low mass galaxies. I also developed a technique to improve the accuracy of LF by accounting for gravitational lensing magnification bias. Secondly, Lyman alpha (Ly ) emission from galaxies can probe the intergalactic medium (IGM) ionization state as Ly photons are strongly attenuated by neutral hydrogen, but this requires disentangling physics on pc to Gpc scales. I developed a new forward-modeling Bayesian framework combining cosmological IGM simulations with interstellar medium models to infer the IGM neutral hydrogen fraction from observations of Ly emission. My thesis presents new measurements of the neutral fraction at z 7 and z 8, which, along with other independent constraints, provide increasing evidence for the bulk of reionization occurring at z 6 8. This is consistent with reionization being driven by ultra-faint galaxies with a low average ionizing photon escape fraction. We also show that reionization impacts Ly emission from different galaxy populations in different ways: UV bright galaxies living in overdense regions that reionize early have potentially visible Ly even in a highly neutral IGM. The upcoming James Webb Space Telescope was designed to observe galaxies at Cosmic Dawn. Throughout this thesis I have made predictions for what JWST may observe in the context of high redshift galaxy evolution.
