Download or read book X ray Diversity in Old Star Clusters written by Smriti Vats and published by . This book was released on 2018 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: The X-ray sky is host to a variety of objects with very distinct properties and underlying physics. In particular, groups of stars known as star clusters are excellent environments to study an array of X-ray sources. In this thesis, I discuss the properties of low-luminosity X-ray sources in old star clusters from two distinct standpoints – the properties of faint X-ray sources within old open clusters, and the cooling of accretion-heated neutron-star crusts in low-mass X-ray binary (LMXB) systems in globular clusters. The first part of the thesis focuses on the properties of close, interacting binary star populations in old open clusters. These properties are a powerful diagnostic of the stellar dynamics taking place inside the cluster. I used X-ray and optical telescope data to unravel the nature of such sources. I determined the total X-ray luminosity per unit mass of the cluster and found that the results support earlier findings that old open clusters are more luminous in X-rays than other old stellar populations. In the second part of the thesis, I studied the cooling of accretion-heated neutron-star crusts in two LMXBs. Using X-ray monitoring observations of the neutron stars during quiescence, I followed the cooling of the crusts over time. Such studies of the thermal evolution of an accretion-heated neutron-star crust help in improving our understanding of the structure and composition of the crust, and how the thermal conductivities of different neutron stars vary under different physical conditions.
Download or read book Compact Stellar X ray Sources written by Walter Lewin and published by Cambridge University Press. This book was released on 2006-04-06 with total page 667 pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray astronomy is the prime available window on astrophysical compact objects: black holes, neutron stars and white dwarfs. In this book, prominent experts provide a comprehensive overview of the observations and astrophysics of these objects. This is a valuable reference for graduate students and active researchers.
Download or read book Star Clusters IAU S266 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2010-02-04 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt: Star clusters are important to many areas of astronomy, and as the basic building blocks of galaxies, they can be used as key diagnostic tools within a wide range of disciplines in astrophysics. Star cluster populations are powerful tracers of the formation, assembly and evolutionary history of their parent galaxies. Although their importance has been recognised for decades, only in recent years has this area seen a major investment in time and effort. IAU Symposium 266 consolidates the expertise of leading researchers from a variety of topical subfields in astrophysics, to provide a comprehensive presentation of cutting-edge developments in theory, observations and simulations of star clusters and star cluster systems across a range of sizes and epochs. This volume gives an account of this forefront research, answering fundamental questions that will improve our understanding of numerous related issues and show how this field will take its next major step forward.
Download or read book Environments of X ray Sources in External Galaxies written by David M. Clark and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Star clusters provide a unique opportunity to study both the environments and progenitors associated with compact objects. Star-forming galaxies are abundant in both star clusters and X-ray point sources. The latter are candidates for X-ray binaries (XRBs) containing a compact object left behind after the death of a massive star. I study the environments of compact objects by focusing on X-ray point sources and massive star clusters in the two star-forming galaxies, the Antennae and NGC 1569.
Download or read book Cosmological Aspects of X Ray Clusters of Galaxies written by W.C. Seitter and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NATO Advanced Study Institute "Cosmological Aspects of X-Ray Clus ters of Galaxies" took place in Vel en , Westphalia, Germany, from June 6 to June 18, 1993. It addressed the fruitful union of two topics, cosmology and X-ray clus ters, both of which carry substantial scientific weight at the beginning of the last decenium of the last century in the second millenium of our era. The so far largest X-ray "All-Sky Survey", observed by the ROSAT X-ray satel lite, and ROSAT's deep pointed observations, have considerably enlarged the base of X-ray astronomy, particularly concerning extragalactic sources. Cosmology has gained significant impetus from the large optical direct and spectroscopic surveys, based on high quality 2-dimensional receivers at large telescopes and powerful scan ning devices, harvesting the full information 1 content from the older technique of employing photographic plates. Radioastronomy and IR-astronomy with IRAS, as well as r-astronomy with GRO, continue and strengthen the role of extragalactic research. The rapidly growing computer power in data reduction and data storage facilities support the evolution towards large-number statistics. A most significant push was given to early cosmology by the needs of physics in trying to unravel the nature of forces which govern our material world. The topic of the ASI was chosen because it opens new vistas on this for ever new problem: the universe. Clusters of galaxies probe large-scale matter distributions and the structure of space-time.
Download or read book The Evolution of Galactic X Ray Binaries written by J. Truemper and published by Springer Science & Business Media. This book was released on 1986-02-28 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the NATO Advanced Research Workshop, Ringberg-Castle, Rottach-Egern, Germany, June 17-21, 1985
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 Diversity of Neutron Stars written by David L. Kaplan and published by Universal-Publishers. This book was released on 2004 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron stars are invaluable tools for exploring stellar death, the physics of ultra-dense matter, and the effects of extremely strong magnetic fields. The observed population of neutron stars is dominated by the >1000 radio pulsars, but there are distinct sub-populations that, while fewer in number, can have significant impact on our understanding of the issues mentioned above. These populations are the nearby, isolated neutron stars discovered by ROSAT, and the central compact objects in supernova remnants. The studies of both of these populations have been greatly accelerated in recent years through observations with the Chandra X-ray Observatory and the XMM-Newton telescope. First, we discuss radio, optical, and X-ray observations of the nearby neutron stars aimed at determining their relation to the Galactic neutron star population and at unraveling their complex physical processes by determining the basic astronomical parameters that define the population---distances, ages, and magnetic fields---the uncertainties in which limit any attempt to derive basic physical parameters for these objects. We conclude that these sources are 1e6 year-old cooling neutron stars with magnetic fields above 1e13 Gauss. Second, we describe the hollow supernova remnant problem: why many of the supernova remnants in the Galaxy have no indication of central neutron stars. We have undertaken an X-ray census of neutron stars in a volume-limited sample of Galactic supernova remnants, and from it conclude that either many supernovae do not produce neutron stars contrary to expectation, or that neutron stars can have a wide range in cooling behavior that makes many sources disappear from the X-ray sky.
Download or read book X Ray Optical Study Low Core Density Globular Clusters NGC6144 E3 written by Shih-Hao Lan and published by LAP Lambert Academic Publishing. This book was released on 2014-07-31 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: Binary stars play important roles in globular cluster formation and evolution. The dynamical process and the energy transfer of the binaries and the stars can strongly affect the dynamical evolution of the globular cluster. The early study of variable X-ray sources in globular clusters showed these sources are likely to be X-ray binaries formed through two-body tidal capture or three-body interaction. According to the selection bias, there were only luminous X-ray sources detected and most are believe to be neutron star or black hole binaries. With the advance of instrument in sensitivity and spectral resolution, more low-luminosity X-ray sources were found. Many faint X-ray sources are believed to result from close binary systems: CVs, ABs, qLMXBs, and MSPs. We report on the Chandra X-ray Observatory and Hubble Space Telescope observation of two low core density globular clusters, NGC6144 and E3. The number of faint X-ray sources in these two clusters is higher than a prediction based on collision frequency, but is closer to that based on mass. Our observations strongly suggest that the compact binary systems in NGC6144 and E3 are primordial in origin.
Download or read book The Soft X Ray Cosmos Rosat Science Symposium written by Eric M. Schlegel and published by American Institute of Physics. This book was released on 1994 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ROSAT Science Symposium was held in November 1993 in order to showcase the results obtained thus far using ROSAT (the Rontgen Satellite) and to provide a forum for discussion regarding the means for extracting the maximum amount of information from ROSAT data. This proceedings volume contains th
Download or read book Very Old and Very Young Compact Objects written by David Aaron Pooley and published by . This book was released on 2003 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis comprises the results of two distinct areas of research, namely, X-ray studies of Galactic globular clusters and X-ray studies of recent core collapse supernovae. My analyses of the Chandra X-ray Observatory observations of the globular clusters NGC 6752 and NGC 6440 revealed as many low-luminosity X-ray sources as was in the entire census of globular cluster sources with the previous best X-ray imaging instrument, Rontgensatellit. In the observation of NGC 6752, I detect 6 X-ray sources within the 10':5 core radius and 13 more within the 115" half-mass radius down to a limiting luminosity of Lx = 1030 ergs s-l for cluster sources. Based on a reanalysis of archival data from the Hubble Space Telescope and the Australia Telescope Compact Array, I make 12 optical identifications and one radio identification. Based on X-ray and optical properties of the identifications, I find 10 likely cataclysmic variables (CVs), 1-3 likely RS CVn or BY Dra systems, and 1 or 2 possible background objects. Of the 7 sources for which no optical identifications were made, one was detected in the archival radio data, and another was found to be a millisecond pulsar. Of the remaining sources, I expect that 2-4 are background objects and that the rest are either CVs or millisecond pulsars whose radio emission has not been detected. These and other Chandra results on globular clusters indicate that the dozens of CVs per cluster expected by theoretical arguments are being found. The findings to date also suggest that the ratio of CVs to other types of X-ray sources is remarkably similar in clusters of very different structural parameters.
Download or read book The New Cosmos written by David J. Eicher and published by Cambridge University Press. This book was released on 2015-12-03 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: A fascinating and spectacular exploration of the cosmos that provides readers with a definitive view of the latest discoveries.
Download or read book Dynamics of Young Star Clusters and Associations written by Cathie Clarke and published by Springer. This book was released on 2015-09-11 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: Where do most stars (and the planetary systems that surround them) in the Milky Way form? What determines whether a young star cluster remains bound (such as an open or globular cluster), or disperses to join the field stars in the disc of the Galaxy? These questions not only impact understanding of the origins of stars and planetary systems like our own (and the potential for life to emerge that they represent), but also galaxy formation and evolution, and ultimately the story of star formation over cosmic time in the Universe. This volume will help readers understand our current views concerning the answers to these questions as well as frame new questions that will be answered by the European Space Agency's Gaia satellite that was launched in late 2013. The book contains the elaborated notes of lectures given at the 42nd Saas-Fee Advanced Course “Dynamics of Young Star Clusters & Associations" by Cathie Clarke (University of Cambridge) who presents the theory of star formation and dynamical evolution of stellar systems, Robert Mathieu (University of Wisconsin) who discusses the kinematics of star clusters and associations, and I. Neill Reid (S pace Telescope Science Institute) who provides an overview of the stellar populations in the Milky Way and speculates on from whence came the Sun. As part of the Saas-Fee Advanced Course Series, the book offers an in-depth introduction to the field serving as a starting point for Ph.D. research and as a reference work for professional astrophysicists.
Download or read book Protostars and Planets V written by Bo Reipurth and published by University of Arizona Press. This book was released on 2007 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt: 'Protostars and Planets V' builds on the latest results from recent advances in ground and space-based astronomy and in numerical computing techniques to offer the most detailed and up-to-date picture of star and planet formation - including the formation and early evolution of our own solar system.
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 787 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts, which has appeared in semi-annual volumes since 1969, is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. It is prepared under the auspices of the International Astronomical Union (according to a resolution adopted at the 14th General Assembly in 1970). Astronomy and Astrophysics Abstracts aims to present a comprehensive documenta tion of literature in all fields of astronomy and astrophysics. Every effort will be made to ensure that the average time interval between the date of receipt of the original literature and publication of the abstracts will not exceed eight months. This time interval is near to that achieved by monthly abstracting journals, compared to which our system of accumu lating abstracts for about six months offers the advantage of greater convenience for the user. Volume 31 contains literature published in 1982 and received before July 15, 1982; some older literature which was received late and which is not recorded in earlier volumes is also included. We acknowledge with thanks contributions to this volume by Dr. J. Bouska, Prague, who surveyed journals and publications in Czech and supplied us with abstracts in English .
Download or read book Clusters of Galaxies Volume 3 Carnegie Observatories Astrophysics Series written by John S. Mulchaey and published by Cambridge University Press. This book was released on 2004-09-23 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Series of review papers covering clusters of galaxies and related phenomena.
Download or read book Astronomy and Astrophysics for the 1980 s Volume 2 written by National Research Council and published by National Academies Press. This book was released on 1983-02-01 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:
