The Star Formation History of Virgo Spiral Galaxies
The Star Formation History of Virgo Spiral Galaxies

Author: Cirino Pappalardo

Publisher:

Published: 2010

Total Pages: 171

ISBN-13:

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This thesis investigates the influence of ram pressure stripping on the star formation history of cluster spiral galaxies. Ram pressure stripping is the hydrodynamical interaction between the interstellar medium (ISM) of a spiral galaxy that is moving inside the potential well of a cluster, and the intracluster medium (ICM). If the dynamical pressure exerted by the ICM is larger than the restoring force due to the galactic potential, the galaxy loses gas from the outer disk. The Virgo cluster is an ideal laboratory to study environmental effects on galaxy evolution, because it is rich in spirals and dynamically young. From observations we know that the amount of atomic gas in Virgo spirals is less than that of galaxies in the field. In particular cluster spirals show truncated HI disks (Giovanelli & Haynes 1983, Cayatte et al. 1990). For those galaxies that also show a symmetrical stellar distribution, ram pressure stripping is the most probably origin of the gas-disk truncation.

The Road to Galaxy Formation
The Road to Galaxy Formation

Author: William C. Keel

Publisher: Springer Science & Business Media

Published: 2002-09-20

Total Pages: 266

ISBN-13: 9781852335748

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Written by one of the leading authorities in the field, this is one of the first book's to describe one of today's most important problems in cosmology - the formation of galaxies. The book tackles this great puzzle by discusses the beginnings of the process from cosmological observations and calculations, considers the broad features of galaxies that we need to explain and what we know of their later history. The author compares the competing theories for galaxy formation and considers the progress expected from new generations of powerful telescopes both on earth and in space. An intriguing text on one of today's greatest and most profound puzzles.

The Stellar Populations and Evolution of Virgo Cluster Galaxies
The Stellar Populations and Evolution of Virgo Cluster Galaxies

Author: Joel C. Roediger

Publisher:

Published: 2009

Total Pages: 418

ISBN-13:

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Using a combination of optical and near-infrared photometry, we have studied both the resolved and integrated stellar populations for a sample of Virgo cluster galaxies spanning the full range of galaxian parameters. The derived stellar population properties are compared against galaxy structural and environmental measures to gauge the importance of these factors in establishing galaxy star formation histories and chemical evolution. Although galaxy colours do not uniquely probe a galaxy's star formation history, meaningful results may be obtained if considered in a relative sense. We find that colour profiles reflect variations in both stellar age and metallicity within galaxies. We also uncover systematic variations in colour gradients, and thus age/metallicity gradients, along the Hubble sequence, such that age and metallicity gradients become increasingly negative toward later Hubble types. However, only weak correlations exist between galaxies' stellar populations and their structure and environment. The correlations we find suggest that the star formation histories of gas-rich galaxies are strongly influenced by gas removal within the cluster, while their chemical evolution is due to a combination of stellar mass-dependent enrichment and outflow retention. The assembly of gas-poor giant galaxies is consistent with a hierarchical scenario wherein gas-rich mergers dominate by number. Gas-poor dwarfs differ from the giants, however, appearing as the product of environmentally-driven evolution. Spiral galaxies bridge the dwarf-giant gap, whereby merging and gas-stripping signatures are imprinted in their stars. Early-type spirals seem to have fallen into the cluster sooner than the later types, thereby ceasing star formation in their disks at earlier epochs. The bulges of both types, however, appear to have grown via merging. The nature of this merging (minor versus major) remains unknown. Irregular galaxies exhibit signs of a recent gravitational encounter that has redistributed both their stars and gas, the latter of which caused recent star formation.

Deep Millimeter Surveys: Implications For Galaxy Formation And Evolution
Deep Millimeter Surveys: Implications For Galaxy Formation And Evolution

Author: David H Hughes

Publisher: World Scientific

Published: 2001-10-29

Total Pages: 223

ISBN-13: 9814492094

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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.

Stellar Disk Evolution and Gaseous Disk Turbulence of Dwarf Irregular Galaxies
Stellar Disk Evolution and Gaseous Disk Turbulence of Dwarf Irregular Galaxies

Author: Hong-Xin Zhang

Publisher: Springer

Published: 2016-08-27

Total Pages: 179

ISBN-13: 3662528673

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This book focuses on the stellar disk evolution and gas disk turbulence of the most numerous galaxies in the local Universe – the dwarf galaxies. The “outside-in” disk shrinking mode was established for a relatively large sample of dwarf galaxies for the first time, and this is in contrast to the “inside-out” disk growth mode found for spiral galaxies. Double exponential brightness profiles also correspond to double exponential stellar mass profiles for dwarf galaxies, which is again different from most spiral galaxies. The cool gas distribution in dwarf galaxies was probed with the spatial power spectra of hydrogen iodide (HI) gas emission, and provided indirect evidence that inner disks of dwarf galaxies have proportionally more cool gas than outer disks. The finding that no correlation exists between gas power spectral indices and star formation gave important constraints on the relation between turbulence and star formation in dwarf galaxies.

The Interstellar Medium in Galaxies
The Interstellar Medium in Galaxies

Author: Harley A. Thronson Jr.

Publisher: Springer

Published: 2013-12-21

Total Pages: 565

ISBN-13: 9400905955

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This book contains the proceedings of the sixth Eurographics Workshop on Vir tual Environments. The event took place from June 1 to June 2, 2000, in Am sterdam. We hope that readers will find these proceedings to be valuable, not only for virtual environment researchers, but also for practitioners developing or using virtual environment applications. We are glad to report that visibility of the workshop continues to expand and that virtual environment researchers and practitioners from allover the world are submitting papers. This year, 40 papers and case studies were submitted of which 20 were accepted. In addition, we are glad to see that the focus of the workshop is also expanding. We accepted 6 research papers on evaluation of virtual environments and there was a broad sampling of other topics. We would like to thank all those involved in organizing the symposium. In particular, thanks go to Mieke Brune who was in charge of the local organization. In addition, we want to thank the international program committee for their excellent, yet laborious, job in reviewing all submitted papers. The quality of the workshop is a reflection of the quality of the submitted papers and the quality of the reviewing process.