Download or read book Cosmological implications of low surface brightness galaxies PHD written by David Sprayberry and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinematics and Star Formation Properties of Low Surface Brightness Galaxies PHD written by Timothy Edward Pickering and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extending the Realm of Galaxies to the Low Surface Brightness Universe written by Brisa Mancillas Vaquera and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The exploration of diffuse light emission and the outskirts of galaxies in the regime of the Low Surface Brightness (LSB) is of utmost importance to understand the formation mechanism of galaxy evolution, and is essential to constrain the current theoretical models and numerical simulations in the cosmological context. Observational data, both in optical and radio emission, complemented with hydrodynamical cosmological numerical simulations provide us a crucial information about the morphological properties of substructures surrounding massive galaxies, as well as the mass distribution, molecular gas content and star formation of LSB galaxies such as the recently discovered Ultra Diffuse Galaxies (UDGs).This thesis presents several analysis addressed to the study of these schemes. In first instance, motivated in the most recent works about optimized deep imaging surveys observed with the CFHT telescope, which have revealed prominent LSB fine structures classified like tidal tails, stellar streams and shells, we have computed statistics of an hydrodynamical numerical simulation in order to interpret observations and make inferences about the past mass assembly of galaxies. We made a census of these substructures and computed their survival time. We also studied their dependence with several properties like the projection and the surface brightness. We found that shells and streams remains visible around 4 Gyr and they are mainly associated to minor mergers and a continuous diffuse gas accretion, while tidal tails have a durability time of around 1 Gyr and are correlated with major merger events. In parallel, in this work we made use of a semi-empirical approach to build-up a mock catalog with the aim to make predictions about scaling relations and constrain physical parameters of UDGs and LSB galaxies.On the other hand, we have performed CO spectroscopy surveys of UDGs observed at IRAM-30m to quantify the molecular gas content. The selected galaxies were conformed by sources from several environments and different properties, including objects like the very red galaxies Dragonfly 44 and DGSAT I. We have obtained unprecedented upper limits of their CO mass (few 10^6 - 10^7 solar masses). We also made CO observations at IRAM-30m to detect molecular gas content in a sample of four early-type galaxies that exhibit prominent shell galaxies like the case of NGC 0474 and Arp 230. Our goal is to test the phase wrapping formation model proposed in numerical simulations. We detected a molecular mass of around 10^8 solar masses in several shells of one galaxy of our sample and we report the mass upper limits for the other cases.
Download or read book The Properties and Evolution of Low Surface Brightness Galaxies written by Willem Jan Geert de Blok and published by . This book was released on 1997 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 1997 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Large Survey for Very Low Surface Brightness Galaxies written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Resolution Optical Velocity Fields of Low Surface Brightness Galaxies and the Density Profiles of Dark Matter Halos written by Rachel Kuzio De Naray and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Properties and Evolution of Low Surface Brightness Galaxies written by Willem Jan Geert De Blok and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Surface Brightness and Size Constraints on Galaxy Survey Counts and Evolution written by Michael James Dorris and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding the formation and evolution of structure in the universe requires accurate quantification of populations of galaxies. The traditional single-variable luminosity function that has been used to quantify galaxy populations has been found lacking because the galaxy luminosity function has major discrepancies between surveys. Many authors have sought to resolve these discrepancies by finding correlations with other galaxy properties. Thus, galaxy statistics are increasingly being recast as multivariate functions. Here we make the case for one such popular function -- a bivariate brightness function in luminosity and surface brightness. To recover actual galaxy counts survey limits must be consistently applied in the same quantities used to construct the statistic. In particular, surface brightness is a natural second variable to use because the criteria used to select objects from an astronomical image are typically surface brightness and size. We construct a model for predicting the number of galaxies observed as a function of redshift and morphological type, excluding effects of evolution. We illustrate the effect upon galaxy counts due to the inclusion of surface brightness bias compared to the inclusion of the cosmological K-correction, the robustness of the method against uncertainty in the bivariate brightness function parameters, and the sensitivity of the expected galaxy counts to survey limits. Comparing observation against our no-evolution model can then yield evolution effects as a function of galaxy morphology -- if we can reliably classify galaxy morphology for large surveys. We focus on methods that can be applied directly to existing photometric catalogs, using the GOODS ACS data set to illustrate our methods. We first consider an attempt to directly extract galaxy morphology by means of a "concentration index'' calculated from aperture photometry. We find this method lacking in discriminatory power and dominated by significant error both in the base aperture photometry and in the fits derived thereof. This classification scheme we then compare to one derived from using a new neural network technique, Spatial Relational Learning. This algorithm not only produces error-free learning based upon the most closely biological neural model to date, but also allows for the extraction of classification rules rather than mere use as a "black box.'' We find that a simple two-variable classification scheme of b-v color and a best-fit Gaussian FWHM parameter, already a standard output of the most commonly used photometric extraction pipeline software, provides highly reasonable morphological classification. With this in hand, we can consider the task of extracting redshift distributions by morphological type from existing photometric catalogs to compare against our no-evolution models. In the case of the GOODS ACS data, we find evidence of significantly faster and more recent evolution among early-type, elliptical galaxies than late-type, disk galaxies. We then turn to consider the Sloan Digital Sky Survey; aside from its massive statistical potential, we consider Sloan because it also gives us the opportunity to explicate the use of non-isophotal detection limits and their effect upon the procedure we have laid out thus far. However, we show that even beyond the problem of shallower redshift coverage (and uncertainty in photometric redshifts), the SDSS is not well-suited for an analysis of this type. A galaxy survey must have a reasonably well-defined set of characteristic survey limits drawn from the actual detection pipeline in order to be useful for our no-evolution model. Nevertheless, even a relatively crude isophotal approximation to survey detection limits illustrates both the robustness of our approach and the pitfalls of morphology-sensitive selection criteria for object detection. Finally, in reviewing the history of hierarchical structure formation theory, our results suggest that the differing evolution epochs observed in the GOODS data argue away from the classical concept of one morphological type of galaxies evolving into another (e.g. via mergers) and more toward morphology-dependent physical processes. In particular we find for disk galaxies, long formation times for the thin disk structure, and for elliptical galaxies, star formation rate suppression and morphological shaping due to AGN-driven downsizing.
Download or read book Low Surface Brightness Galaxies and the Galaxy Stellar Mass Function written by R. P. Williams and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Surface Brightness Galaxies in the Red Cluster Survey 2 written by Luis Busta and published by . This book was released on 2014 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gravitational Lensing by Low Surface Brightness Galaxies written by John David Ault and published by . This book was released on 2004 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Oxygen Abundances in Low Surface brightness Galaxies written by Jari Rönnback and published by . This book was released on 1992 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astrophysics written by and published by PediaPress. This book was released on with total page 625 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Low Surface Brightness Galaxies and Their Environments written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In der vorliegenden Dissertation wurde die Lage von Low Surface Brightness (LSB) Galaxien innerhalb der großskaligen Struktur untersucht. Dazu wurde der Sloan Digital Sky Survey herangezogen. Mit diesem Datensatz wurde die mittlere umgebende Galaxiendichte von LSBs innerhalb von Sphären mit einem Radius, der zwischen 0.8 und 8 Mpc variiert wurde, bestimmt. Zum Vergleich wurde die mittlere umgebende Galaxiendichte von High Surface Brightness (HSB) Galaxien ermittelt. Ferner wurde erstmalig das LSB-HSB Galaxy Bias berechnet. Aus diesen Studien resultiert, dass LSBs im Vergleich zu HSBs eher in Gebieten mit geringer umgebender Galaxiendichte zu finden sind. LSBs favorisieren die äußeren Bereiche der Wände und Filamente, die die großskalige Struktur des Universums bilden. Darüber hinaus wurden die Daten auf das Vorkommen von Aktiven Galaktischen Kernen (engl.: AGN) in LSBs analysiert. Es zeigte sich, dass der Anteil von AGNs in LSBs unerwartet hoch bei ∼ 10% liegt.
Download or read book The Stellar and Gaseous Content of Massive Low Surface Brightness Disk Galaxies written by Patricia Marie Knezek and published by . This book was released on 1993 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt:
