Suzaku Studies of White Dwarf Stars and the Galactic X-ray Background Emission

Suzaku Studies of White Dwarf Stars and the Galactic X-ray Background Emission PDF Author: Takayuki Yuasa
Publisher: Springer Science & Business Media
ISBN: 4431542191
Category : Science
Languages : en
Pages : 164

Get Book Here

Book Description
This thesis presents a study of the origin of an apparently extended X-ray emission associated with the Galactic ridge. The study was carried out with broadband spectra obtained from mapping observations in the Galactic bulge region conducted in 2005–2010 by the Suzaku space X-ray observatory. The spectra were analyzed with a newly constructed X-ray spectral model of an accreting white dwarf binary that is one of the proposed candidate stars for the origin of the Galactic ridge emission in the higher energy band. Fitting of the observed Galactic ridge spectra with the model showed that there is another spectral component that fills the gap between the observed X-ray flux and the component expected from the accreting white dwarf spectral model in the lower energy band. This additional soft spectral component was nicely explained by an X-ray spectral model of normal stars. The result, together with previously reported high-resolution imaging results, strongly supports the idea that the Galactic ridge X-ray emission is an assembly of dim, discrete X-ray point sources.

Suzaku Studies of White Dwarf Stars and the Galactic X-ray Background Emission

Suzaku Studies of White Dwarf Stars and the Galactic X-ray Background Emission PDF Author: Takayuki Yuasa
Publisher: Springer Science & Business Media
ISBN: 4431542191
Category : Science
Languages : en
Pages : 164

Get Book Here

Book Description
This thesis presents a study of the origin of an apparently extended X-ray emission associated with the Galactic ridge. The study was carried out with broadband spectra obtained from mapping observations in the Galactic bulge region conducted in 2005–2010 by the Suzaku space X-ray observatory. The spectra were analyzed with a newly constructed X-ray spectral model of an accreting white dwarf binary that is one of the proposed candidate stars for the origin of the Galactic ridge emission in the higher energy band. Fitting of the observed Galactic ridge spectra with the model showed that there is another spectral component that fills the gap between the observed X-ray flux and the component expected from the accreting white dwarf spectral model in the lower energy band. This additional soft spectral component was nicely explained by an X-ray spectral model of normal stars. The result, together with previously reported high-resolution imaging results, strongly supports the idea that the Galactic ridge X-ray emission is an assembly of dim, discrete X-ray point sources.

White Dwarfs: Cosmological and Galactic Probes

White Dwarfs: Cosmological and Galactic Probes PDF Author: E. Sion
Publisher: Springer Science & Business Media
ISBN: 9781402036934
Category : Science
Languages : en
Pages : 288

Get Book Here

Book Description
The emphasis on white dwarf stars and cosmology arises from the most recent advances in cosmological and galactic structure research in which white dwarf stars are playing a very prominent role. Examples are Type Ia supernovae (i.e. white dwarf supernovae), the origin and evolution of the universe, the age of the galactic disk, cosmochronology using white dwarfs in globular clusters and galactic clusters, and the physics of accretion onto compact (very dense) stars. As an assisting guide to the reader, we have included, by invitation, comprehensive review articles in each of the four major areas of the book, white dwarf supernovae, cosmology, accretion physics and galactic structure. The reviews include introductory material that they build upon. The book is suitable and most useful to advanced undergraduates, graduate students and scientific professionals (e.g. astronomers, astrophysicists, cosmologists, physicists).

Study of the Galactic Diffuse X-ray Emission with the Suzaku Satellite

Study of the Galactic Diffuse X-ray Emission with the Suzaku Satellite PDF Author: Hideki Uchiyama
Publisher:
ISBN:
Category : X-ray astronomy
Languages : en
Pages : 133

Get Book Here

Book Description


Unlocking the Secrets of White Dwarf Stars

Unlocking the Secrets of White Dwarf Stars PDF Author: Hugh M. Van Horn
Publisher: Springer
ISBN: 331909369X
Category : Science
Languages : en
Pages : 335

Get Book Here

Book Description
White dwarfs, each containing about as much mass as our Sun but packed into a volume about the size of Earth, are the endpoints of evolution for most stars. Thousands of these faint objects have now been discovered, though only a century ago only three were known. They are among the most common stars in the Milky Way Galaxy, and they have become important tools in understanding the universe. Yet a century ago only three white dwarfs were known. The existence of these stars completely baffled the scientists of the day, and solving the mysteries of these strange objects required revolutionary advances in science and technology, including the development of quantum physics, the construction and utilization of large telescopes, the invention of the digital computer, and the ability to make astronomical observations from space. This book tells the story of the growth in our understanding of white dwarf stars, set within the context of the relevant scientific and technological advances. Part popular science, part historical narrative, this book is authored by one of the astrophysicists who participated directly in uncovering some of the secrets of white dwarf stars.

White Dwarfs: Advances in Observation and Theory

White Dwarfs: Advances in Observation and Theory PDF Author: M.A. Barstow
Publisher: Springer Science & Business Media
ISBN: 940112020X
Category : Science
Languages : en
Pages : 555

Get Book Here

Book Description
The European Workshop on White Dwarfs was initiated by Prof. V. Weidemann, with the first meeting held in Kiel (FRG) in 1974. Since then a similar workshop has been held almost every two years: Frascati (1976), Tel Aviv (1978), Paris (1981), Kiel (1984), Frascati (1986) and Toulouse (1990). Two major IAU colloquia have also been devoted to the study of white dwarfs (No. 53, Rochester NY, 1979; No. 114, Hanover, NH, 1988). Our most recent meeting, the 8th Workshop, marks a number of important advances in both observational and theoretical studies of white dwarfs. This coincides with a significant expansion in the size of the community active in the field, as was clear from an increase in the number of participants between this workshop (77) and that in Toulouse (46), just two years ago. Key parts of any workshop are the discussion sessions following the pa pers. However, these are difficult to record and, very often, the 'live' flavour of the debates is lost. During this workshop we carried out an experiment, recording the discussion sessions on video tape and then transcribing these later for the proceedings. Although the recordings were made in non-studio conditions with regard to lighting and noise, only a very small part was unin telligible. All participants were given an opportunity to check their questions and answers for scientific accuracy and to correct any errors arising in the transcription process.

White Dwarfs

White Dwarfs PDF Author: Domitilla de Martino
Publisher: Springer Science & Business Media
ISBN: 9401002150
Category : Science
Languages : en
Pages : 443

Get Book Here

Book Description
Proceedings of the NATO Advanced Research Workshop, held in Naples, Italy, 24-28 June 2002

Unlocking the Secrets of White Dwarf Stars

Unlocking the Secrets of White Dwarf Stars PDF Author: Hugh Van Horn
Publisher: Springer
ISBN: 9783319093703
Category : Science
Languages : en
Pages : 324

Get Book Here

Book Description
White dwarfs, each containing about as much mass as our Sun but packed into a volume about the size of Earth, are the endpoints of evolution for most stars. Thousands of these faint objects have now been discovered, though only a century ago only three were known. They are among the most common stars in the Milky Way Galaxy, and they have become important tools in understanding the universe. Yet a century ago only three white dwarfs were known. The existence of these stars completely baffled the scientists of the day, and solving the mysteries of these strange objects required revolutionary advances in science and technology, including the development of quantum physics, the construction and utilization of large telescopes, the invention of the digital computer, and the ability to make astronomical observations from space. This book tells the story of the growth in our understanding of white dwarf stars, set within the context of the relevant scientific and technological advances. Part popular science, part historical narrative, this book is authored by one of the astrophysicists who participated directly in uncovering some of the secrets of white dwarf stars.

A Suzaku Search for Dark Matter Emission Lines in the X-ray Brightest Galaxy Clusters

A Suzaku Search for Dark Matter Emission Lines in the X-ray Brightest Galaxy Clusters PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

Book Description


Cosmological Aspects of X-Ray Clusters of Galaxies

Cosmological Aspects of X-Ray Clusters of Galaxies PDF Author: W.C. Seitter
Publisher: Springer Science & Business Media
ISBN: 9401110220
Category : Science
Languages : en
Pages : 500

Get Book Here

Book Description
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.

White Dwarfs as Probes of Fundamental Physics (IAU S357)

White Dwarfs as Probes of Fundamental Physics (IAU S357) PDF Author: Martin A. Barstow
Publisher: Cambridge University Press
ISBN: 9781108492027
Category : Science
Languages : en
Pages : 400

Get Book Here

Book Description
White dwarfs are the most numerous members of the stellar graveyard. More than ninety percent of all stars will end their lives as white dwarfs. Research on these objects is fascinating in its own right, requiring developments in atomic data and the study of properties of matter under extreme conditions. However, these studies also have enormous impact on other areas of astrophysics, including: cosmology, the composition of extrasolar planets and fundamental physics. The proceedings of IAU Symposium 357 bring together experts from different branches of science working on white dwarfs, but also astronomers with expertise in a wide range of relevant disciplines. The resulting papers are organized around several key themes: SN Ia progenitors, debris from extrasolar planetary systems, fundamental physics, precision studies of white dwarf structure and stellar physics and Galactic evolution. They provide a framework for guiding the direction of white dwarf research for the next decade.