Download or read book Studying Globular Clusters in the Dwarf Galaxy NGC 247 Using Subaru Hyper Suprime Cam Imaging written by Vakini Santhanakrishnan and published by . This book was released on 2016 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: While globular clusters (GCs) are among the most ancient stellar systems in the universe, there are still lingering questions about how and where they formed. There is relatively little known about GCs in spiral galaxies beyond the Milky Way. We analyzed confirmed GCs, examined putative GC candidates, and looked for new GCs around the nearby dwarf spiral galaxy NGC 247 at about 3.5 Mpc away in the Sculptor group, based on wide-field imaging data from the Subaru Hyper Suprime-Cam (HSC), with a 1.5 degree field of view. The extremely wide-area coverage, depth, and image quality of HSC provide great potential for studying GCs around nearby galaxies. Using colors, magnitudes, and sizes of spectroscopically-confirmed objects, we defined criteria for selecting GC candidates in NGC 247. We examined candidates visually and were able to eliminate objects that were previously classified to be GC candidates, as well as find new GC candidates. Spectroscopic follow-up is planned to confirm some of the new GC candidates.
Download or read book Globular Clusters written by C. Martinez Roger and published by Cambridge University Press. This book was released on 1999-10-28 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: An accessible introduction to globular clusters for graduate students, and a comprehensive and up-to-date reference for researchers.
Download or read book The Photometric Properties of Extragalactic Globular Cluster Systems written by Zachary Grove Jennings and published by . This book was released on 2017 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Globular Clusters (GCs) are powerful tools for understanding the formation of galaxies. GCs are located in the halos of galaxies and, due to their age and density, have borne witness to the major formation events of a galaxy's lifetime. One may study these objects using a wide array of techniques and datasets, including wide-field ground-based imaging, deep space-based imaging, and spectroscopy. All approaches involve tradeoffs, and in this work we consider a variety of ways to study GC systems in imaging data. We examine a wide-field HST/ACS mosaic of the nearby lenticular galaxy NGC 3115, selecting a high-quality GC sample using the superior resolution of the ACS data. We find strong color bimodality in the GC system of NGC 3115 and examine a number of trends in the properties of the GC system. Next, we consider the situation where one is limited to ground-based imaging, where contaminants to the GC population are a major concern. We detail a novel statistical methodology in which we treat the GC population and the contaminant population as a mixture model, and evaluate the model in a Bayesian context. We demonstrate the performance of the model on mock data, and note some areas where current analysis of GC systems may be missing information using traditional selection techniques. We also apply this Bayesian methodology to a subset of SLUGGS survey galaxies with high-quality photometry from either the MegaCam instrument on the Canada France-Hawaii Telescope or the SuprimeCam instrument on the Subaru Telescope. In most cases, the mixture model recovers the GC system well, often finding the traditional bimodality and providing well-calibrated statistical uncertainties for the global parameters of the GC system. Finally, we examine the object NGC 3628 UCD1, a star cluster slightly more massive than the largest GCs. We identify that UCD1 is located in a stellar stream around the galaxy NGC 3628, and therefore is in the process of being accreted. We characterize UCD1 both in wide-field SuprimeCam imaging and in Keck/ESI spectroscopy, and identify a number of interesting parallels between UCD1 and omegaCen, the largest Milky Way GC.
Download or read book Structure and Dynamics of Globular Clusters written by S. G. Djorgovski and published by . This book was released on 1993 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of the Globular Cluster NGC 6397 Using Multi wavelength Hubble Space Telescope Images written by Liliana Ivonne Lopez Mendez and published by . This book was released on 2008 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extended Structures in Globular Clusters written by Pete Kuzma and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our view and understanding of globular clusters in the Milky Way have undergone massive changes over the past few decades. No longer are globular clusters seen as the perfect example of simple stellar populations, as almost all Galactic globular clusters are now known to contain star-to-star light element abundance variations, and a small subset contain heavy element abundance ranges. However, not only can a lot be learnt from studying the stars within globular clusters, but also from the stars outside globular clusters, beyond the tidal radius. Whether the structure is in the form of tidal tails such as the iconic tails of Palomar 5, or part of a much larger scale stellar feature such as the stellar stream belonging to the disrupting dwarf galaxy Sagittarius or the wealth of streams in the halo of M31, the environs of Galactic globular clusters can be used as insights into the formation of the globular clusters themselves and to the shape and formation of the Milky Way's halo. This thesis focuses on exploring extended features of Milky Way globular clusters. First, by increasing the spatial coverage and kinematics of the tidal tails of Palomar 5 through low to intermediate resolution spectroscopy from the 2df AAOmega spectrograph on the Anglo-Australian Telescope. We identify 39 new and recover 8 previously deter- mined members in the tidal stream through radial velocities, line strengths and photomet- ric information. Second, we performed a wide field photometric survey of southern Galactic globular clusters with the complementary imagers MegaCam on the 6.5m Clay Telescope, and the DECam, on the 4m Blanco Telescope. We present the results for the four clusters analysed during the PhD candidature: NGC 1261, NGC 1851, NGC 5824 and NGC 7089 (M2). We find diffuse large low surface density envelopes containing NGC 1261, NGC 1851 and M2, with a tentative detection of an envelope surrounding NGC 5824. We discuss the origins of the envelopes and how the features we have uncovered, along with Palomar 5's tidal tails, may influence our understanding of the Galactic halo and globular cluster formation.
Download or read book Globular Cluster Systems written by Keith M. Ashman and published by Cambridge University Press. This book was released on 2008-12-11 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: Globular clusters are roughly spherical, densely packed groups of stars found around galaxies. Most globular clusters probably formed at the same time as their host galaxies. Therefore they provide a unique fossil record of the conditions during the formation and early evolution of galaxies. This volume presents a comprehensive review of globular cluster systems. It summarizes their observed properties and shows how these constrain models of the structure of stars, the formation and evolution of galaxies and globular clusters, and the age of the Universe. For graduate students and researchers, this timely volume provides the definitive reference on globular cluster systems.
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 Cosmic Evolution written by Eric J. Chaisson and published by Harvard University Press. This book was released on 2001-02-16 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chaisson addresses some of the most basic issues we can contemplate: the origin of matter and the origin of life, and the ways matter, life, and radiation interact and change with time. He designs for us an expansive yet intricate model depicting the origin and evolution of all material structures.
Download or read book Pathways to Discovery in Astronomy and Astrophysics for the 2020s written by National Academies of Sciences, Engineering, and Medicine and published by . This book was released on 2022-08-04 with total page 615 pages. Available in PDF, EPUB and Kindle. Book excerpt: The steering committee was specifically asked to (1) provide an overview of the current state of astronomy and astrophysics science, and technology research in support of that science, with connections to other scientific areas where appropriate; (2) identify the most compelling science challenges and frontiers in astronomy and astrophysics, which shall motivate the committee’s strategy for the future; (3) develop a comprehensive research strategy to advance the frontiers of astronomy and astrophysics for the period 2022-2032 that will include identifying, recommending, and ranking the highest-priority research activities; (4) utilize and recommend decision rules, where appropriate, that can accommodate significant but reasonable deviations in the projected budget or changes in urgency precipitated by new discoveries or unanticipated competitive activities; (5) assess the state of the profession, including workforce and demographic issues in the field, identify areas of concern and importance to the community, and where possible, provide specific, actionable, and practical recommendations to the agencies and community to address these areas. This report proposes a broad, integrated plan for space- and ground-based astronomy and astrophysics for the decade 2023-2032. It also lays the foundations for further advances in the following decade.
Download or read book The First Galaxies in the Universe written by Abraham Loeb and published by Princeton University Press. This book was released on 2013-01-15 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive, self-contained introduction to one of the most exciting frontiers in astrophysics today: the quest to understand how the oldest and most distant galaxies in our universe first formed. Until now, most research on this question has been theoretical, but the next few years will bring about a new generation of large telescopes that promise to supply a flood of data about the infant universe during its first billion years after the big bang. This book bridges the gap between theory and observation. It is an invaluable reference for students and researchers on early galaxies. The First Galaxies in the Universe starts from basic physical principles before moving on to more advanced material. Topics include the gravitational growth of structure, the intergalactic medium, the formation and evolution of the first stars and black holes, feedback and galaxy evolution, reionization, 21-cm cosmology, and more. Provides a comprehensive introduction to this exciting frontier in astrophysics Begins from first principles Covers advanced topics such as the first stars and 21-cm cosmology Prepares students for research using the next generation of large telescopes Discusses many open questions to be explored in the coming decade
Download or read book Stellar Candles for the Extragalactic Distance Scale written by Danielle Alloin and published by Springer Science & Business Media. This book was released on 2003-10-20 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews the current status with respect to both theory and observation of the extragalactic distance scale. A sufficient accuracy is required both for a precise determination of the cosmological parameters and also in order to achieve a better understanding of physical processes in extragalactic systems. The "standard candles", used to set up the extragalactic distance scale, reviewed in this book include cepheid variables, RR Lyrae variables, novae, Type Ia and Type II supernovae as well as globular clusters and planetary nebulae.
Download or read book Very Low Mass Stars and Brown Dwarfs written by Rafael Rebolo and published by Cambridge University Press. This book was released on 2000-11-27 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides a state-of-the-art review of our current knowledge of brown dwarfs and very low-mass stars. The hunt for and study of these elusive objects is currently one of the most dynamic areas of research in astronomy for two reasons. Brown dwarfs bridge the gap between stars and planets, and they may constitute an important part of the 'dark matter' of the Universe. This volume presents review articles from a team of international authorities who gathered at a conference in La Palma to assess the spectacular progress that has been made in this field in the last few years.
Download or read book Astrophotonics written by Stefano Minardi and published by VCH. This book was released on 2012-04-04 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by well-known scientists in the field with vast experience in teaching astrophotonics, this is the first book to bridge astronomy and photonics for the benefit of developing new astronomical instrumentation. The textbook is clearly structured and covers four main methods relevant to observational astronomy: adaptive optics, photometry, interferometry and spectroscopy. It follows a progressive didactical path in photonics, starting from fundamentals of wave- and micro-optics and developing step-by-step the formalisms required for the treatment of optical multilayers, fiber optics and diffraction/holographic gratings. This approach allows students with a physics/engineering background to learn about the problematic of observational astronomy, while, conversely, students of astronomy are exposed to topics in modern photonics. Each chapter is divided into three main sections devoted to the discussion of astronomical concepts required to size an instrument designed for the particular method, the photonic concepts that most suit that instrument, and an analysis of existing, related photonic instruments. A set of exercises and a bibliography complete each chapter. Appendices include a short review of fundamentals of wave optics and photon detectors, plus an overview of project design and management using a real-life example of an astronomical instrumentation project. With its review of the latest instrumentation and techniques, this is invaluable for graduate and post-graduate students in astronomy, physics and optical engineering.
Download or read book Astronomy written by Adam Frank and published by W. W. Norton. This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A textbook that is not written like a textbook.
Download or read book Data Analysis in Astronomy written by V. di Gesù and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: The international Workshop on "Data Analysis in Astronomy" was in tended to give a presentation of experiences that have been acqui red in data analysis and image processing, developments and appli cations that are steadly growing up in Astronomy. The quality and the quantity of ground and satellite observations require more so phisticated data analysis methods and better computational tools. The Workshop has reviewed the present state of the art, explored new methods and discussed a wide range of applications. The topics which have been selected have covered the main fields of interest for data analysis in Astronomy. The Workshop has been focused on the methods used and their significant applications. Results which gave a major contribution to the physical interpre tation of the data have been stressed in the presentations. Atten tion has been devoted to the description of operational system for data analysis in astronomy. The success of the meeting has been the results of the coordinated effort of several people from the organizers to those who presen ted a contribution and/or took part in the discussion. We wish to thank the members of the Workshop scientific committee Prof. M. Ca paccioli, Prof. G. De Biase, Prof. G. Sedmak, Prof. A. Zichichi and of the local organizing committee Dr. R. Buccheri and Dr. M.C. Macca rone together with Miss P. Savalli and Dr. A. Gabriele of the E. Majo rana Center for their support and the unvaluable part in arranging the Workshop.
Download or read book New Worlds New Horizons in Astronomy and Astrophysics written by National Research Council and published by National Academies Press. This book was released on 2011-02-04 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Driven by discoveries, and enabled by leaps in technology and imagination, our understanding of the universe has changed dramatically during the course of the last few decades. The fields of astronomy and astrophysics are making new connections to physics, chemistry, biology, and computer science. Based on a broad and comprehensive survey of scientific opportunities, infrastructure, and organization in a national and international context, New Worlds, New Horizons in Astronomy and Astrophysics outlines a plan for ground- and space- based astronomy and astrophysics for the decade of the 2010's. Realizing these scientific opportunities is contingent upon maintaining and strengthening the foundations of the research enterprise including technological development, theory, computation and data handling, laboratory experiments, and human resources. New Worlds, New Horizons in Astronomy and Astrophysics proposes enhancing innovative but moderate-cost programs in space and on the ground that will enable the community to respond rapidly and flexibly to new scientific discoveries. The book recommends beginning construction on survey telescopes in space and on the ground to investigate the nature of dark energy, as well as the next generation of large ground-based giant optical telescopes and a new class of space-based gravitational observatory to observe the merging of distant black holes and precisely test theories of gravity. New Worlds, New Horizons in Astronomy and Astrophysics recommends a balanced and executable program that will support research surrounding the most profound questions about the cosmos. The discoveries ahead will facilitate the search for habitable planets, shed light on dark energy and dark matter, and aid our understanding of the history of the universe and how the earliest stars and galaxies formed. The book is a useful resource for agencies supporting the field of astronomy and astrophysics, the Congressional committees with jurisdiction over those agencies, the scientific community, and the public.
