Download or read book The Complex Broad band X ray Spectra of Seyfert Galaxies written by Kimberly Weaver and published by . This book was released on 1993 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Broad band X ray Spectra of Seyfert 1 Galaxies written by Alessandra De Rosa and published by . This book was released on 2002 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Broad Band X ray Spectra of Cosmic Sources written by COSPAR. Scientific Assembly and published by . This book was released on 2000 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book BBXRT written by Peter J. Serlemitsos and published by . This book was released on 1993 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book The Gamma Ray Observatory written by and published by . This book was released on 1991 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spectroscopy of Compact Extragalactic X ray Sources written by Stephen S. Holt and published by . This book was released on 1980 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X ray Emitting GHz Peaked Spectrum Galaxies written by and published by . This book was released on 2010 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a dynamical-radiative model we recently developed to describe the physics of compact, GHz-Peaked-Spectrum (GPS) sources, the relativistic jets propagate across the inner, kpc-sized region of the host galaxy, while the electron population of the expanding lobes evolves and emits synchrotron and inverse-Compton (IC) radiation. Interstellar-medium gas clouds engulfed by the expanding lobes, and photoionized by the active nucleus, are responsible for the radio spectral turnover through free-free absorption (FFA) of the synchrotron photons. The model provides a description of the evolution of the GPS spectral energy distribution (SED) with the source expansion, predicting significant and complex high-energy emission, from the X-ray to the [gamma]-ray frequency domain. Here, we test this model with the broad-band SEDs of a sample of eleven X-ray emitting GPS galaxies with Compact-Symmetric-Object (CSO) morphology, and show that: (i) the shape of the radio continuum at frequencies lower than the spectral turnover is indeed well accounted for by the FFA mechanism; (ii) the observed X-ray spectra can be interpreted as non-thermal radiation produced via IC scattering of the local radiation fields off the lobe particles, providing a viable alternative to the thermal, accretion-disk dominated scenario. We also show that the relation between the hydrogen column densities derived from the X-ray (N{sub H}) and radio (N{sub HI}) data of the sources is suggestive of a positive correlation, which, if confirmed by future observations, would provide further support to our scenario of high-energy emitting lobes.
Download or read book The Impact of Space Experiments on Our Knowledge of the Physics of the Universe written by Franco Giovannelli and published by Springer Science & Business Media. This book was released on 2004-08-03 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space experiments have opened practically all electromagnetic windows on the Universe. A discussion of the most important results obtained with multi-frequency photonic astrophysics experiments will provide new input to advance our knowledge of physics, very often in its more extreme conditions. A multitude of high quality data across the whole electromagnetic spectrum came at the scientific community's disposal a few years after the beginning of the Space Era. With these data we are attempting to explain the physics governing the Universe and its origin, which continues to be a matter of the greatest curiosity for humanity. In this book we describe the latest steps of the investigations born with the advent of space experiments. We highlight the most important results, identify unsolved problems, and comment on perspectives we can reasonably expect. This book aims to provide a useful tool for the reader who is not specialized in space astrophysics and for students. Therefore, the book is written in the form of a review with a still reasonable length, taking into account the complexity of the arguments discussed. We do not claim to present a complete picture of the physics governing the Universe, but have rather selected particular topics for a more thorough discussion. A cross section of essays on historical, modern, and philosophical topics is offered and combined with personal views into tricks of the space astrophysics trade.
Download or read book The X ray Background written by Xavier Barcons and published by Cambridge University Press. This book was released on 1992-07-31 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: A review of the current observational knowledge and understanding of the cosmic X-ray background.
Download or read book Handbook of X ray and Gamma ray Astrophysics written by Cosimo Bambi and published by Springer Nature. This book was released on with total page 5912 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1992 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Average X Ray Gamma Ray Spectra of Seyfert Galaxies From Ginga and OSSE and the Origin of the Cosmic X Ray Background written by and published by . This book was released on 1995 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have obtained the first average 2-500 keV spectra of Seyfert galaxies, using the data from Ginga and GRO OSSE. Our sample contains 3 classes of objects with markedly different spectra: radio-quiet Seyfert 1s and 2s, and radio-loud Seyfert 1s. The average radio-quiet Seyfert 1 spectrum is well- fitted by a power law continuum with the energy spectral index approximately equal 0.9, a Compton reflection component corresponding to a ~ 2x covering solid angle, and ionized absorption. There is a high-energy cutoff in the incident power law continuum: the e-folding energy is E(sub c) approximately equal 0.6 (sup +0.8, sub -0.3)MeV. The simplest model that describes this spectrum is Comptonization in a relativistic optically-thin thermal corona above the surface of an accretion disk. Radio-quiet Seyfert 2s show strong neutral absorption, and there is an indication that their X-ray power laws are intrinsically harder, although the Seyfert 1 spectrum with = 0.9 and strong reflection cannot be ruled out by the data. Finally, the radio-loud Seyfert spectrum has alpha approximately equal 0.7, moderate neutral absorption, E (sub c) = 0.4(sup +0.7, sub -0.2) MeV, and no or little Compton reflection. This is incompatible with the radio-quiet Seyfert 1 spectrum, and probably indicating that the X-rays are beamed away from the accretion disk in these objects. The average spectra of Seyferts integrated over redshift with a power law evolution can explain the hard X-ray spectrum of the cosmic background. The hump at ~ 30 keV in that spectrum is due to the dominant contribution of Seyfert 2s.
Download or read book Literature 1989 Part 1 written by Astronomisches Rechen-Institut and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1433 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: "Astronomy and Astrophysics Abstracts has appeared in semi-annual volumes since 1969 and it has already become one of the fundemental publications in the fields of astronomy, astrophysics and neighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. ...The abstracts are classified under more than a hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world." Space Science Review# "Dividing the whole field plus related subjects into 108 categories, each work is numbered and most are accompanied by brief abstracts. Fairly comprehensive cross-referencing links relevant papers to more than one category, and exhaustive author and subject indices are to be found at the back, making the catalogues easy to use. The series appears to be so complete in its coverage and always less than a year out of date that I shall certainly have to make a little more space on those shelves for future volumes." The Observatory Magazine#
Download or read book Quasars and Active Galactic Nuclei written by Ajit K. Kembhavi and published by Cambridge University Press. This book was released on 1999-03-11 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: The latest observations and theoretical models are combined in this clear, pedagogic textbook for advanced undergraduates and graduate students.
Download or read book The Physics and Evolution of Active Galactic Nuclei written by Hagai Netzer and published by Cambridge University Press. This book was released on 2013-09-16 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive introduction to the theory underpinning our study of active galactic nuclei and the ways we observe them.
Download or read book Science With The Cherenkov Telescope Array written by The Cta Consortium and published by World Scientific. This book was released on 2018-12-31 with total page 365 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the science to be carried out by the upcoming Cherenkov Telescope Array, a major ground-based gamma-ray observatory that will be constructed over the next six to eight years. The major scientific themes, as well as core program of key science projects, have been developed by the CTA Consortium, a collaboration of scientists from many institutions worldwide.CTA will be the major facility in high-energy and very high-energy photon astronomy over the next decade and beyond. CTA will have capabilities well beyond past and present observatories. Thus, CTA's science program is expected to be rich and broad and will complement other major multiwavelength and multimessenger facilities. This book is intended to be the primary resource for the science case for CTA and it thus will be of great interest to the broader physics and astronomy communities. The electronic version (e-book) is available in open access.
