Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Download The Environmental Impact Of The Virgo Cluster On The Evolution Of Dwarf Irregular Galaxies full books in PDF, epub, and Kindle. Read online The Environmental Impact Of The Virgo Cluster On The Evolution Of Dwarf Irregular Galaxies ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Author : Henry Lee
Publisher :
ISBN 13 :
Total Pages : 252 pages
Book Rating : 4.:/5 (62 download)
Download or read book The Environmental Impact of the Virgo Cluster on the Evolution of Dwarf Irregular Galaxies written by Henry Lee and published by . This book was released on 2001 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Jacqueline Michelle Dunn
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (183 download)
Download or read book The Stellar Content and Star Formation Rates of Dwarf Irregular Galaxies written by Jacqueline Michelle Dunn and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The star formation histories and evolution of 70 dwarf irregular galaxies that reside in differing local and global environments are investigated. Local environment is defined by the local galaxy number density, where high indicates at least one neighbor within 200 kpc and low indicates no neighbors within 1 Mpc. Global environment is classified as either the field or a galaxy group / cluster. The shallow gravitational potentials of these galaxies are more susceptible to changes in morphology and dynamics by external perturbations, making dwarf irregular galaxies ideal candidates for a study on the role of environment in galaxy evolution. Absolute magnitudes, colors, central surface brightnesses, and star formation rates were compared using UBVRIJHK and Halpha photometry. With a high degree of statistical significance, galaxies in local high density environments have brighter central and effective surface brightnesses, while those in global high density environments have brighter absolute magnitudes, central and effective surface brightnesses, and higher star formation rates. However, no difference is seen among the different environments when considering star formation rates normalized by HI mass. Sersic profiles were fit to the V and R band surface brightness profiles of the galaxies. No correlation exists between structural characteristics and environment. Spectral energy distribution models were generated by varying the rate of stellar formation and amplitude to replicate periodic burst and constant star formation rate scenarios. Of the 28 galaxies for which star formation history analysis was performed, roughly half were well fit by one of the models. Periodic burst systems account for roughly half of those galaxies, with the remaining galaxies being better represented by continuously star forming systems. The star formation histories are uncorrelated with both local and global environmental classifications. Numerical simulations provide insight into the effects of differing gravitational environments, and indicate global environment having a larger influence on the physical properties of a dwarf galaxy. The star formation histories and structural properties of dwarf irregular galaxies were found to be independent of environment, indicating that cluster membership and proximity to a neighboring galaxy have no systematic long-term effects on the evolution of the objects in this study.
Author : Polychronis Papaderos
Publisher : Springer Science & Business Media
ISBN 13 : 3642220185
Total Pages : 347 pages
Book Rating : 4.6/5 (422 download)
Download or read book Dwarf Galaxies: Keys to Galaxy Formation and Evolution written by Polychronis Papaderos and published by Springer Science & Business Media. This book was released on 2012-04-23 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dwarf galaxy research constitutes an extremely vibrant field of astrophysical research, with many long-standing questions still unsettled and new ones constantly arising. The intriguing diversity of the dwarf galaxy population, observed with advanced ground-based and space-borne observatories over a wide spectral window providing an unprecedented level of detail, poses new challenges for both observers and theoreticians. The aim of this symposium was to bring together these two groups to exchange ideas and new results on the many evolutionary aspects of and open issues concerning dwarf galaxies. The main topics addressed include: the birth of dwarf galaxies: theoretical concepts and observable relics across wavelengths and time, the morphological, structural and chemical evolution of dwarf galaxies, possible evolutionary connections between early-type and late-type dwarfs, the star formation history of dwarf galaxies and its dependence on intrinsic and environmental properties, the origin and implications of starburst activity in dwarf galaxies, the fate of dwarfish systems born out of tidally ejected matter in galaxy collisions.
Author : Ryan Leaman
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (858 download)
Download or read book Constraints on Environmental and Secular Effects on the Chemodynamical Evolution of Dwarf Galaxies written by Ryan Leaman and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents observations and analysis relating to the understanding of processes that govern the formation and evolution of low mass galactic systems. In particular we have focused on separating out the contribution to the chemical and dynamical evolution of dwarf galaxies due to solely secular (internal) processes compared to external effects from the local environment a galaxy resides in. Our observational data focus on an extremely isolated dwarf galaxy, WLM, which we demonstrate has had a uniquely quiescent tidal history, thereby making it an excellent test case for such a study. With spectroscopic and photometric observations of the resolved stars and neutral gas in WLM we have been able to characterize the chemical, structural and kinematic properties of this gas rich dwarf galaxy. As WLM has not been subject to strong tidal or ram-pressure stripping of its stellar and gaseous populations, we have been able to compare the dynamical evolution and chemical history of WLM to theoretical models which are environment independent. A differential comparison of WLM to more environmentally processed dwarf galaxies in the Local Group has revealed that WLM's structural and dynamical state is far from the idealized picture of dIrrs as thin gas-rich rotating systems. The stellar component of WLM shows equal parts rotation and dispersion, and both the gaseous and stellar structural properties show an intrinsically thick axisymmetric configuration. The time evolution of the random (dispersion) component of the stellar orbital energy shows an increase with stellar age, which we show is consistent with secular processes alone - such as disk heating from giant molecular clouds and dark matter substructure. While the degree to which the thick structural and dynamically hot configuration for WLM is surprising, its chemical properties show remarkably consistent values with other galaxies of the same halo mass. Comparing the spatial chemical trends in WLM with other dwarf galaxies we identify a correlation between the strength of the radial abundance gradients and the angular momentum content of dwarf galaxies in the Local Group. Finally using a large sample of chemical abundance measurements in the literature for dwarf galaxies and star clusters, we demonstrate that their distributions of chemical elements all exhibit a binomial form, and use the statistical properties of the distributions to identify a new metric for differentiating low luminosity stellar systems. We further apply a simple binomial chemical evolution model to describe the self-enrichment and pre-enrichment in the two classes of objects, and suggest how this may be used to place constraints on the formation environments of globular clusters in particular.
Author : Hong-Xin Zhang
Publisher : Springer
ISBN 13 : 3662528673
Total Pages : 179 pages
Book Rating : 4.6/5 (625 download)
Download or read book Stellar Disk Evolution and Gaseous Disk Turbulence of Dwarf Irregular Galaxies written by Hong-Xin Zhang and published by Springer. This book was released on 2016-08-27 with total page 179 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Author : Kelly Ann Douglass
Publisher :
ISBN 13 :
Total Pages : 322 pages
Book Rating : 4.:/5 (1 download)
Download or read book Observational Evidence of the Large-scale Environmental Influence on Dwarf Galaxy Evolution written by Kelly Ann Douglass and published by . This book was released on 2017 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate how the cosmic environment affects galaxy evolution in the Universe by studying gas-phase chemical abundances and other galaxy properties as a function of the large-scale environment and local density of galaxies. Using spectroscopic observations from the Sloan Digital Sky Survey Data Release 7, we estimate the oxygen and nitrogen abundances of 993 star-forming void dwarf galaxies and 759 star-forming dwarf galaxies in denser regions. We use the Direct Te method for calculating the gas-phase chemical abundances in the dwarf galaxies because it is best suited for low metallicity, low mass galaxies. A substitute for the [OII] 3727 doublet is developed, permitting oxygen abundance estimates of SDSS dwarf galaxies at all redshifts with the Direct Te method. We find that star-forming void dwarf galaxies have slightly higher oxygen abundances than star-forming dwarf galaxies in denser environments, but we find that void dwarf galaxies have slightly lower nitrogen abundances and lower N/O ratios than galaxies in denser regions. At smaller scales, we find that only the presence of a neighboring galaxy within 0.05 Mpc/h or 0.1 r_virial, or the presence of a group within 0.05 Mpc/h, influences a dwarf galaxy's evolution. Dwarf galaxies within 0.05 Mpc/h or 0.1 r_virial of another galaxy tend to be bluer, have higher sSFRs, have higher oxygen abundances, and have lower N/O ratios than average. In contrast, galaxies within 0.05 Mpc/h of the center of the closest group have lower oxygen and nitrogen abundances than average. We also investigate how a galaxy transitions through the color-magnitude diagram, evolving from a blue, star-forming spiral or irregular galaxy in the blue sequence to a red elliptical galaxy in the red cloud through the green valley. We discover that combining a galaxy's color, color gradient, and inverse concentration index determines a galaxy's location on the color-magnitude diagram. The results indicate that, in the green valley, there is a lower fraction of void dwarf galaxies than dwarf galaxies in denser regions. From these analyses, we surmise that void dwarf galaxies experience delayed star formation as predicted by the Lambda CDM cosmology. We also conjecture that cosmic downsizing corresponds to a shift towards star formation in both lower mass objects and void regions closer to the present epoch. We present evidence that void dwarf galaxies may have a higher ratio of dark matter halo mass to stellar mass when compared to dwarf galaxies in denser environments.
Author : Sandra M. Faber
Publisher : Springer Science & Business Media
ISBN 13 : 1461247624
Total Pages : 475 pages
Book Rating : 4.4/5 (612 download)
Download or read book Nearly Normal Galaxies written by Sandra M. Faber and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is sometimes said that astronomy is the crossroads of physics. In the same spirit, it can forcefully be argued that galaxies are the crossroads of astronomy. Internal pro ces ses within galaxies involve all of the fundamental components of astrophysics: stellar evolution, star formation, low-density astrophysics, dynamics, hydrodynamics, and high-energy astrophysics. Indeed, one can hardly name an observational datum in any wavelength range on any kind of celestial object that does not provide a useful clue to galaxy formation and evolution. Although internal processes in galaxies until recently occupied most of our attention, we now know that it is also vital to relate galaxies to their environment. How galaxies congregate in larger structures and are in turn influenced by them are crucial questions for galactic evolution. On a grander level we have also come to regard galaxies as the basic building blocks of the universe, the basic units whereby the large scale structure of the universe is apprehended and quantified. On a grander level still, we also believe strongly that galaxies are the direct descendents of early density irregularities in the Big Bang. Galaxy properties are now viewed as providing a crucial constraint on the physics of the Big Bang and a vital link between the macroscopic and microscopic structure of the universe.
Author : Ana B. Heller
Publisher :
ISBN 13 :
Total Pages : 171 pages
Book Rating : 4.:/5 (234 download)
Download or read book Structure and Star Formation Regimes of Low Surface Brightness Dwarf Irregular Galaxies in the Virgo Cluster written by Ana B. Heller and published by . This book was released on 2001 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : Irini Pantelaki
Publisher :
ISBN 13 :
Total Pages : 143 pages
Book Rating : 4.:/5 (946 download)
Download or read book Chemical Evolution of Dwarf Irregular Galaxies written by Irini Pantelaki and published by . This book was released on 1988 with total page 143 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : A. Aparicio
Publisher : Cambridge University Press
ISBN 13 : 9780521632553
Total Pages : 628 pages
Book Rating : 4.6/5 (325 download)
Download or read book Stellar Astrophysics for the Local Group written by A. Aparicio and published by Cambridge University Press. This book was released on 1998-06-13 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the new subject of extragalactic stellar astrophysics - for both graduate students and researchers working in astrophysics.
Author : S. Böhme
Publisher : Springer Science & Business Media
ISBN 13 : 3662123827
Total Pages : 1180 pages
Book Rating : 4.6/5 (621 download)
Download or read book Astronomy and Astrophysics Abstracts written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-12-14 with total page 1180 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: Astronomy and Astrophysics Abstracts has appeared in semi-annual volumes since 1969 and it has already become one of the fundamental publications in the fields of astronomy, astrophysics and neighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. ... The abstracts are classified under more than hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world." Space Science Reviews #1 "Dividing the whole field plus related subjects into 108 categories, each work is numbered and most are accompanied by brief abstracts. Fairly comprehensive cross-referencing links relevant papers to more than one category, and exhaustive author and subject indices are to be found at the back, making the catalogues easy to use. The series appears to be so complete in its coverage and always less than a year out of date that I shall certainly have to make a little more space on those shelves for future volumes." The Observatory Magazine #1
Author : International Astronomical Union. Colloquium
Publisher : Cambridge University Press
ISBN 13 : 9780521852043
Total Pages : 456 pages
Book Rating : 4.8/5 (52 download)
Download or read book Near-Field Cosmology with Dwarf Elliptical Galaxies (IAU C198) written by International Astronomical Union. Colloquium and published by Cambridge University Press. This book was released on 2005 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of IAUC 198, covering important issues related to near-field cosmology with dwarf elliptical galaxies.
Author : Cirino Pappalardo
Publisher :
ISBN 13 :
Total Pages : 171 pages
Book Rating : 4.:/5 (834 download)
Download or read book The Star Formation History of Virgo Spiral Galaxies written by Cirino Pappalardo and published by . This book was released on 2010 with total page 171 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Author : Royal Astronomical Society of Canada
Publisher :
ISBN 13 :
Total Pages : 316 pages
Book Rating : 4.:/5 (318 download)
Download or read book Journal de la Societe Royale D'astronomie Du Canada written by Royal Astronomical Society of Canada and published by . This book was released on 2002 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Library catalogue in 1911" (31 p.) appended to v. 4.
Author :
Publisher :
ISBN 13 :
Total Pages : 886 pages
Book Rating : 4.F/5 ( download)
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2006 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author : International Astronomical Union. Colloquium
Publisher : Cambridge University Press
ISBN 13 : 9780521849081
Total Pages : 586 pages
Book Rating : 4.8/5 (49 download)
Download or read book Outskirts of Galaxy Clusters (IAU C195) written by International Astronomical Union. Colloquium and published by Cambridge University Press. This book was released on 2004-12-16 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the proceedings of the International Astronomical Union Colloquium no. 195, held in Torino, Italy in 2004. The meeting investigated the formation of galaxies within a full cosmological context, focusing on the outer regions of galaxy clusters. The observed correlation of optical and radio properties of galaxies with their environment indicates that the formation and evolution of galaxies is intimately linked to the formation of large scale structure. With chapters written by leading authorities in the field, this timely volume investigates the role of the environment in determining the properties of galaxies. It describes the distribution of matter and galaxies on the largest scales in the Universe, the processes of cluster and galaxy formation, their role and interplay. This is a valuable collection of review articles for professional astronomers.
Author : Astronomisches Rechen-InstitutARI
Publisher : Springer Science & Business Media
ISBN 13 : 3642517587
Total Pages : 1746 pages
Book Rating : 4.6/5 (425 download)
Download or read book Literature 1997, Part 1 written by Astronomisches Rechen-InstitutARI and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1746 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
