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Author : Ivan Kostyuk
Release : 2023
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Book Synopsis Investigating Lyman Continuum Escape Fractions of High Redshift Galaxies During the Era of Reionization by : Ivan Kostyuk
Download or read book Investigating Lyman Continuum Escape Fractions of High Redshift Galaxies During the Era of Reionization written by Ivan Kostyuk. This book was released on 2023. Available in PDF, EPUB and Kindle. Book excerpt:
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Release : 2014
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Book Synopsis Unveiling the Epoch of Reionization by Simulations and High-redshift Galaxies by :
Download or read book Unveiling the Epoch of Reionization by Simulations and High-redshift Galaxies written by . This book was released on 2014. Available in PDF, EPUB and Kindle. Book excerpt: The Epoch of Reionization marks after recombination the second major change in the ionization state of the universe, going from a neutral to an ionized state. It starts with the appearance of the first stars and galaxies; a fraction of high-energy photons emitted from galaxies permeate into the intergalactic medium (IGM) and gradually ionize the hydrogen, until the IGM is completely ionized at z~6 (Fan et al., 2006). While the progress of reionization is driven by galaxy evolution, it changes the ionization and thermal state of the IGM substantially and affects subsequent structure and galaxy formation by various feedback mechanisms. Understanding this interaction between reionization and galaxy formation is further impeded by a lack of understanding of the high-redshift galactic properties such as the dust distribution and the escape fraction of ionizing photons. Lyman Alpha Emitters (LAEs) represent a sample of high-redshift galaxies that are sensitive to all these galactic properties and the effects of reionization. In this the...
Author : Donald E. Osterbrock
Release : 2006
Genre : Science
Kind : eBook
Book Rating : 344/5 ( reviews)
Book Synopsis Astrophysics Of Gas Nebulae and Active Galactic Nuclei by : Donald E. Osterbrock
Download or read book Astrophysics Of Gas Nebulae and Active Galactic Nuclei written by Donald E. Osterbrock. This book was released on 2006. Available in PDF, EPUB and Kindle. Book excerpt: Thoroughly revised and expanded throughout, the new edition is a graduate-level text and reference book on gaseous nebulae, nova and supernova remnants. Much of the new data and new images are from the Hubble Space Telescope with two wholly new chapters being added along with other new features. The previous edition which was tried and tested for thirty years has now been succeeded by a revised, updated, larger edition, which will be valuable to anyone seriously interested in astrophysics.
Author : Jessie Frances Taylor
Release : 2016
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Book Synopsis High Redshift Galaxies as Probes of the Epoch of Reionization by : Jessie Frances Taylor
Download or read book High Redshift Galaxies as Probes of the Epoch of Reionization written by Jessie Frances Taylor. This book was released on 2016. Available in PDF, EPUB and Kindle. Book excerpt: Following the Big Bang, as the Universe cooled, hydrogen and helium recombined, forming neutral gas. Currently, this gas largely resides between galaxies in a highly diffuse state known as the intergalactic medium (IGM). Observations indicate that the IGM, fueled by early galaxies and/or accreting black holes, "reionized" early in cosmic history--the entire volume of the Universe refilling with ionized gas. This thesis analyzes and develops several ways to use observations of high redshift galaxies to probe this period, the Epoch of Reionization (EoR). We examine the redshift evolution of the Ly[alpha] fraction, the percentage of Lyman-break selected galaxies (LBGs) that are Lyman-[alpha] emitting galaxies (LAEs). Observing a sharp drop in this fraction at z~7, many early studies surmised the z~7 IGM must be surprisingly neutral. We model the effect of patchy reionization on Ly[alpha] fraction observations, concluding that sample variance reduces the neutral fraction required. We quantify the prospects for measuring the enhanced spatial clustering of LAEs due to reionization with upcoming observations from the Hyper Suprime Cam. LBGs from that survey provide a useful comparison sample. We consider the effect of foreground "interlopers" on the clustering signal. We conclude that if HSC observes back into the EoR, the abundance and spatial clustering of galaxies and the size distribution of void regions evolve more strongly with redshift for LAEs than LBGs. Moreover, measuring the cross-power spectrum between LAEs and LBGs reduces the interloper effect.We examine line intensity mapping experiments which trace large scale structure by measuring spatial fluctuations in the combined emission, in some convenient spectral line, from individually unresolved galaxies. We develop a technique to separate "interloper" emissions, which these surveys are vulnerable to, at the power spectrum level, based on distortions introduced when the interloper emissions are (incorrectly) assumed to originate from the target redshift. Applying this to a hypothetical [CII] emission survey at z~7, we find the distinctive interloper anisotropy can be used to separate strong foreground CO emission fluctuations.
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?
