Using Quasar Absorption Lines to Probe Cold Gas in High Redshift Galaxies PDF Download

Author: Siwei Zou
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Author: International Astronomical Union. Colloquium
Publisher: Cambridge University Press
ISBN: 9780521852050
Category : Science
Languages : en
Pages : 540

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Review of recent research in the field of quasar absorption line systems.

Author: Jackson Norris
Publisher:
ISBN:
Category :
Languages : en
Pages :

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To understand the formation and evolution of galaxies, it is essential to understand the gas that exists in the vicinity of galaxies. Mg II absorption systems probe the circumgalactic medium (CGM) around galaxies and can provide hints to the nature of the gas. To fully understand the complex structure of the CGM, it is necessary to investigate not only low-ionization transitions such as those of Mg II, but also transition lines associated with more diffuse high-ionization material.We report our analysis of six intervening quasar absorption line systems, which probe the CGM at redshifts 0.4

Author: Patrick Petitjean
Publisher: Atlantica Séguier Frontières
ISBN: 9782863322291
Category : Absorption spectra
Languages : en
Pages : 490

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Author: Frederic Courbin
Publisher: Springer
ISBN: 3540458573
Category : Science
Languages : en
Pages : 202

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Gravitational lensing is by now sufficiently well understood that it can be used as a tool of investigation in other astrophysical areas. Applications include the determination of the Hubble constant, probing the dark matter context of galaxies and the mapping of the universe to the identification of otherwise invisible large-scale structures. Each chapter of the book covers in a self-contained manner a subfield of gravitational lensing, with the double aim of describing in a simple way the basics of the theory and of reviewing the most recent developments as well as applications foreseen in the near future. The book will thus be particularly useful as a high-level textbook for nonspecialist researchers and advanced students wishing to become familiar with the field all the way up to the forefront of research.

Author: Marcel Neeleman
Publisher:
ISBN: 9781321829891
Category :
Languages : en
Pages : 233

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In this thesis we provide insight into the chemical composition, physical conditions and cosmic distribution of atomic gas at high redshift. We study this gas in absorption against bright background quasars in absorption systems known as Damped Ly-alpha Systems (DLAs). These systems contain the bulk of the atomic gas at high redshift and are the likely progenitors of modern-day galaxies. In Chapter 2, we find that the atomic gas in DLAs obeys a mass-metallicity relationship that is similar to the mass-metallicity relationship seen in star-forming galaxies. The evolution of this relationship is linear with redshift, allowing for a planar equation to accurately describe this evolution, which provides a more stringent constraint on simulations modeling DLAs. Furthermore, the concomitant evolution of the mass-metallicity relationship of atomic gas and star-forming galaxies suggests an intimate link between the two. We next use a novel way to measure the physical conditions of the gas by using fine-structure line ratios of singly ionized carbon and silicon. By measuring the density of the upper and lower level states, we are able to determine the temperature, hydrogen density and electron density of the gas. We find that the conditions present in this high redshift gas are consistent with the conditions we see in the local interstellar medium (ISM). A few absorbers have higher than expected pressure, which suggests that they probe the ISM of star-forming galaxies. Finally in Chapter 4, we measure the cosmic neutral hydrogen density at redshifts below 1.6. Below this redshift, the Ly-alpha line of hydrogen is absorbed by the atmosphere, making detection difficult. Using the archive of the Hubble Space Telescope, we compile a comprehensive list of quasars for a search of DLAs at redshift below 1.6. We find that the incidence rate of DLAs and the cosmic neutral hydrogen density is smaller than previously measured, but consistent with the values both locally and at redshifts of about 2. Altogether, these results improve our understanding of atomic gas at high redshift and help illuminate how this important component shapes the galaxies we see today.

Author: Astronomisches Rechen-InstitutARI
Publisher: Springer Science & Business Media
ISBN: 3642517587
Category : Science
Languages : en
Pages : 1746

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Astronomy and Astrophysics Abstracts is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. Two volumes are scheduled to appear per year. Volume 67 records 10,903 papers covering besides the classical fields of astronomy and astrophysics such matters as space flights related to astronomy, lunar and planetary probes and satellites, meteorites and interplanetary matter, X rays and cosmic rays, quasars and pulsars. The abstracts are classified under more than one hundred subject categories thus permitting quick surveying of the bulk of material published on the same topic within six months. For instance, this volume records 119 papers on minor planets, 155 papers on supernovae, and 554 papers on cosmology.

Author: National Research Council
Publisher: National Academies Press
ISBN: 0309058279
Category : Science
Languages : en
Pages : 89

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Author: Jeremy Walsh
Publisher: Springer Science & Business Media
ISBN: 3540483608
Category : Science
Languages : en
Pages : 329

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Author: Space Telescope Science Institute (U.S.). Symposium
Publisher: Cambridge University Press
ISBN: 9780521630979
Category : Science
Languages : en
Pages : 328

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The Hubble Deep Field (HDF) is the deepest optical image of the Universe ever obtained. It is the result of a 150-orbit observing programme with the Hubble Space Telescope. It provides a unique resource for researchers studying the formation and evolution of stars and galaxies. This timely volume provides the first comprehensive overview of the HDF and its scientific impact on our understanding in cosmology. It presents articles by a host of world experts who gathered together at an international conference at the Space Telescope Science Institute. The contributions combine observations of the HDF at a variety of wavelengths with the latest theoretical progress in our understanding of the cosmic history of star and galaxy formation. The HDF is set to revolutionize our understanding in cosmology. This book therefore provides an indispensable reference for all graduate students and researchers in observational or theoretical cosmology.