Download or read book Photometric Redshifts and Clustering of Emission Line Galaxies Selected Jointly by DES and EBOSS written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the results of the first test plates of the extended Baryon Oscillation Spectroscopic Survey. This paper focuses on the emission line galaxies (ELG) population targetted from the Dark Energy Survey (DES) photometry. We analyse the success rate, efficiency, redshift distribution, and clustering properties of the targets. From the 9000 spectroscopic redshifts targetted, 4600 have been selected from the DES photometry. The total success rate for redshifts between 0.6 and 1.2 is 71\% and 68\% respectively for a bright and faint, on average more distant, samples including redshifts measured from a single strong emission line. We find a mean redshift of 0.8 and 0.87, with 15 and 13\% of unknown redshifts respectively for the bright and faint samples. In the redshift range 0.6
Download or read book The Distribution of Star forming Galaxies in Intermediate Redshift Galaxy Clusters written by Steven Michael Crawford and published by . This book was released on 2006 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Galaxy Clustering Photometric Redshifts and Diagnosis of Systematics in the DES Science Verification Data written by and published by . This book was released on 2015 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: We study the clustering of galaxies detected at i
Download or read book The DAFT FADA Survey I Photometric Redshifts Along Lines of Sight to Clusters in the Z written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As a contribution to the understanding of the dark energy concept, the Dark energy American French Team (DAFT, in French FADA) has started a large project to characterize statistically high redshift galaxy clusters, infer cosmological constraints from Weak Lensing Tomography, and understand biases relevant for constraining dark energy and cluster physics in future cluster and cosmological experiments. Aims. The purpose of this paper is to establish the basis of reference for the photo-z determination used in all our subsequent papers, including weak lensing tomography studies. This project is based on a sample of 91 high redshift (z ≥ 0.4), massive (≈> 3 x 1014 M{sub {circle_dot}}) clusters with existing HST imaging, for which we are presently performing complementary multi-wavelength imaging. This allows us in particular to estimate spectral types and determine accurate photometric redshifts for galaxies along the lines of sight to the first ten clusters for which all the required data are available down to a limit of I{sub AB} = 24./24.5 with the LePhare software. The accuracy in redshift is of the order of 0.05 for the range 0.2 ≤ z ≤ 1.5. We verified that the technique applied to obtain photometric redshifts works well by comparing our results to with previous works. In clusters, photo-z accuracy is degraded for bright absolute magnitudes and for the latest and earliest type galaxies. The photo-z accuracy also only slightly varies as a function of the spectral type for field galaxies. As a consequence, we find evidence for an environmental dependence of the photo-z accuracy, interpreted as the standard used Spectral Energy Distributions being not very well suited to cluster galaxies. Finally, we modeled the LCDCS 0504 mass with the strong arcs detected along this line of sight.
Download or read book Higher Resolution Photometric Redshifts for Cosmological Surveys written by Alex Alarcon Gonzalez and published by . This book was released on 2019 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: This PhD thesis is focused on the measurement of photometric redshifts in imaging galaxy surveys and its applications to extract cosmological information. In the first part of this thesis we forecast a galaxy survey with very precise redshift information, which can come either from spectroscopy or many narrow band images, using the Fisher matrix formalism. We use galaxy clustering, how galaxies group together in space, dividing a sample into two subsamples using other observable parameters. Using two overlapping subsamples reduces the sample variance in the observables, which improves the precision with which one can measure the expansion and growth history of the universe. In the second part of this thesis we measure highly precise photometric redshifts using the data from a novel imaging galaxy survey PAUS that contains a unique set of 40 narrow band filters. We develop two algorithms which use maximum likelihood or Bayesian evidence statistics to infer the redshift probability of each galaxy, which requires modeling both the continuum and emission line galaxy flux. The algorithm contains several corrections to account for systematic effects present in the data calibration which are tested in simulations developed for this purpose. The measurement of PAUS redshifts enables the science of the galaxy survey and can also be used to calibrate the redshift distribution of lensing surveys. The last part of this thesis implements for the first time a hierarchical Bayesian model in an N-body simulation to measure the redshift distribution of a lensing survey using both photometric and density information. Weak lensing is a very powerful tool to extract cosmological information, but it is very sensitive to any bias in the mean redshift of a sample of source galaxies. This method consistently combines all sources of information and merges the main techniques used in the literature to estimate redshift distributions.
Download or read book Galaxy Clustering with Spectroscopic and Photometric Redshift Surveys written by Adrian Ashley Collister and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photometric Calibration Procedures written by Velma I. Burns and published by . This book was released on 1972 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lecture Notes in Cosmology written by Oliver Piattella and published by Springer. This book was released on 2018-07-21 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmology has become a very active research field in the last decades thanks to the impressing improvement of our observational techniques which have led to landmark discoveries such as the accelerated expansion of the universe, and have put physicists in front of new mysteries to unveil, such as the quest after the nature of dark matter and dark energy. These notes offer an approach to cosmology, covering fundamental topics in the field: the expansion of the universe, the thermal history, the evolution of small cosmological perturbations and the anisotropies in the cosmic microwave background radiation. Some extra topics are presented in the penultimate chapter and some standard results of physics and mathematics are available in the last chapter in order to provide a self-contained treatment. These notes offer an in-depth account of the above-mentioned topics and are aimed to graduate students who want to build an expertise in cosmology.
Download or read book Large Scale Structures of the Universe written by International Astronomical Union. Symposium and published by Springer Science & Business Media. This book was released on 1988-07-31 with total page 662 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the 130th Symposium of the International Astronomical Union, dedicated to the memory of Marc A. Aaronson (1950-1987), held in Balatonfured, Hungary, June 15-20, 1987
Download or read book From the Fermi Scale to Cosmology written by Alberto Salvio and published by Frontiers Media SA. This book was released on 2019-12-06 with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Curvature Cosmology written by David F. Crawford and published by Universal-Publishers. This book was released on 2006 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Curvature Cosmology proposes a new cosmological model very different from, and more elegant than, the Big-Bang Theory. Curvature Cosmology is based on two major hypotheses that Hubble redshift is due to an interaction of photons with curved spacetime and that there is a pressure that acts to stabilise expansion and provides a static stable universe. The main focus of this book is to describe these two hypotheses in detail and to examine all relevant cosmological data in the context of this new model of the universe. This model proposes that, though evolution of stars and galaxies is evident, the statistical properties of the universe are the same at all places and at all times. In short, the universe is ageless, has no defined beginning (unlike the Big-Bang model), and carries no evidence of expansion, despite the changeability of its components. Curvature Cosmology is a complex book that calls for a paradigm shift in current cosmology and requires at least basic (if not more complex) knowledge of past and current cosmological models and equations.
Download or read book Fundamentals of Cosmology written by James Rich and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 311 pages. Available in PDF, EPUB and Kindle. Book excerpt: A self-contained introduction to general relativity that is based on the homogeneity and isotropy of the local universe. Emphasis is placed on estimations of the densities of matter and vacuum energy, and on investigations of the primordial density fluctuations and the nature of dark matter.
Download or read book Outskirts of Galaxies written by Johan H. Knapen and published by Springer. This book was released on 2017-07-09 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of invited reviews written by world-renowned experts on the subject of the outskirts of galaxies, an upcoming field which has been understudied so far. These regions are faint and hard to observe, yet hide a tremendous amount of information on the origin and early evolution of galaxies. They thus allow astronomers to address some of the most topical problems, such as gaseous and satellite accretion, radial migration, and merging. The book is published in conjunction with the celebration of the end of the four-year DAGAL project, an EU-funded initial training network, and with a major international conference on the topic held in March 2016 in Toledo. It thus reflects not only the views of the experts, but also the scientific discussions and progress achieved during the project and the meeting. The reviews in the book describe the most modern observations of the outer regions of our own Galaxy, and of galaxies in the local and high-redshift Universe. They tackle disks, haloes, streams, and accretion as observed through deep imaging and spectroscopy, and guide the reader through the various formation and evolution scenarios for galaxies. The reviews focus on the major open questions in the field, and explore how they can be tackled in the future. This book provides a unique entry point into the field for graduate students and non-specialists, and serves as a reference work for researchers in this exciting new field.
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.
Download or read book Quasar Astronomy written by Daniel W. Weedman and published by Cambridge University Press. This book was released on 1988-04-14 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: A current account of quasar astronomy that not only summarizes existing results from various techniques but refers to the potentialities of new instruments. All aspects of quasar spectroscopy are discussed and techniques for analyzing quasar data are summarized.
Download or read book Frontiers in Physics 2017 2018 Editor s Choice written by Thomas Beyer and published by Frontiers Media SA. This book was released on 2019-02-22 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Launched in 2013, Frontiers in Physics consists of 18 specialties covering all areas of research in physics. With over 500 published manuscripts, the journal is now indexed in SCIE with the first impact factor coming in 2019. Frontiers in Physics aims to become the largest and most cited open access multidisciplinary physics journal. This eBook collects what the Specialty Chief Editors of the journal believed were the most interesting manuscripts published over the past two years. It is a nice collection, which will offer the reader the chance to have a quick overview of the specialties of the journal and offer a glimpse into the state of the art of physics. We must confess that it has been quite challenging to select only one article per specialty section given the many important manuscripts published by the journal in 2017 and 2018. We invite our reader to have a look at the journal homepage and browse what we have published so far. It includes articles on topics very different from each other, written by both early career scientists and well-known researchers, ranging from the indisputable advance of the field to the more bold. We hope you enjoy reading our first edition of the Frontiers in Physics Editor's Choice eBook! Professor Alex Hansen (Field Chief Editor) and Dr Claudio Bogazzi (Journal Manager)
Download or read book The Realm of the Nebulae written by Edwin Powell Hubble and published by Yale University Press. This book was released on 1982-01-01 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: No modern astronomer made a more profound contribution to our understanding of the cosmos than did Edwin Hubble, who first conclusively demonstrated that the universe is expanding. Basing his theory on the observation of the change in distanct galaxies, called red shift, Hubble showed that this is a Doppler effect, or alteration in the wavelength of light, resulting from the rapid motion of celestial objects away from Earth. In 1935, Hubble described his principal observations and conclusions in the Silliman lectures at Yale University. These lectures were published the following year as "The Realm of the Nebulae," which quickly became a classic work.
