Download or read book High Energy X ray Observations of BL Lacertae Objects written by and published by . This book was released on 1979 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book X ray and Ultraviolet Observations of BL Lacertae Objects written by Claudia Megan Urry and published by . This book was released on 1984 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ultraviolet and X ray Observations of the BL Lac Object PKS 0548 322 written by Claudia Megan Urry and published by . This book was released on 1982 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Observation of X Ray Variability in the BL Lac Object 1ES1959 65 written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper reports X-ray spectral observations of a relatively nearby (z = 0.048) BL Lacertae (BL Lac) object 1ES1959+65, which is a potential TeV emitter. The observations include 31 short pointings made by the Unconventional Stellar Aspect (USA) Experiment on board the Advanced Research and Global Observation Satellite (ARGOS), and 17 pointings by the PCA on board the Rossi X-ray Timing Explorer (RXTE). Most of these observations were spaced by less than 1 day. 1ES1959+65 was detected by the ARGOS USA detector in the range 1-16 keV, and by the PCA in the 2-16 keV range but at different times. During the closely spaced RXTE observations beginning on 2000 July 28, an ending of one flare and a start of another are visible, associated with spectral changes, where the photon index XBL-type blazar, with the X-ray emission likely to originate via the synchrotron process. The USA observations reveal another flare that peaked on 2000 November 14 and doubled the flux within a few days, again associated with spectral changes of the same form. The spectral variability correlated with the flux and timing characteristics of this object that are similar to those of other nearby BL Lacs, and suggest relativistic beaming with a Doppler factor [delta] ≥ 1.6 and magnetic fields of the order of a few mG. We also suggest that the steady component of the X-ray emission--present in this object as well as in other XBLs--may be due to the large-scale relativistic jet (such as measured by Chandra in many radio-loud AGN), but pointing very closely to our line of sight.

Download or read book Variability of Blazars written by E. VALTAOJA (Ed) and published by Cambridge University Press. This book was released on 1992 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: Blazars (also known as BL Lac objects), first discovered in 1978, are unusually energetic objects in the extragalactic universe. About 200 are known or suspected. They are radio sources with highly variable optical and radio emission, as well as high polarisation, and their optical spectra normally have no distinguishable features. It is generally accepted that they belong to that class of galaxies with active galactic nuclei, which are presumed to be driven by infall of matter to a supermassive black hole. In this book researchers give a complete summary of the observations of blazars and the theoretical interpretation. A comprehensive listing of confirmed and candidate objects is included. Mechanisms in which the variability can arise from shocks and relativistic jets are discussed. There are at least four different answers given to the question: what is a blazar? This book is a complete overview of the violent activity observed in these extreme active galactic nuclei.

Download or read book X ray and Ultraviolet Observations of BL Lacertae Objects written by Claudia Megan Urry and published by . This book was released on 1986 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent X ray Observations of Intermediate BL Lac Objects written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present recent ROSAT, ASCA and SAX observations of intermediate BL Lac objects (IBLs), i.e. BL Lacs which are located between high-energy and low-energy peaked BL Lac objects with respect to log (Sx/Sr). Both, the statistical properties of IBLs from the RGB sample and a detailed broad band X-ray spectral analysis of two objects (1424+2401, 1055+5644), point towards a continuous distribution of synchrotron emission peak frequencies among BL Lac objects.

Download or read book The Bl Lac Phenomenon written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-13 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the activities related to two ROSAT investigations: (1) x-ray properties of radio galaxies thought to contain BL Lac type nuclei; and (2) x-ray spectra of a complete sample of flat-spectrum radio sources. The following papers describing the research are provided as attachments: Multiple X-ray Emission Components in Low Power Radio Galaxies; New X-ray Results on Radio Galaxies; Analysis Techniques for a Multiwavelength Study of Radio Galaxies; Separation of X-ray Emission Components in Radio Galaxies; X-ray Emission in Powerful Radio Galaxies and Quasars; Extended and Compact X-ray Emission in Powerful Radio Galaxies; and X-ray Spectra of a Complete Sample of Extragalactic Core-dominated Radio Sources. Worrall, Diana M. Unspecified Center NAG5-1724; NAG5-1882...

Download or read book The Multi Messenger Approach to High Energy Gamma Ray Sources written by Josep M. Paredes and published by Springer Science & Business Media. This book was released on 2007-11-12 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a theoretical and observational overview of the state of the art of gamma-ray astrophysics, and their impact and connection with the physics of cosmic rays and neutrinos. With the aim of shedding new and fresh light on the problem of the nature of the gamma-ray sources, particularly those yet unidentified, this book summarizes contributions to a workshop that continues today.

Download or read book Coordinated Observations of X ray Bright BL Lacertae Objects written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Frontiers of X Ray Astronomy Paper written by Tanaka, Y. and published by . This book was released on 1992 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Very High Energy Cosmic Gamma Radiation written by Felix A. Aharonian and published by World Scientific. This book was released on 2004 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gamma ray astronomy, the branch of high energy astrophysics that studies the sky in energetic ?-ray photons, is destined to play a crucial role in the exploration of nonthermal phenomena in the Universe in their most extreme and violent forms. The great potential of this discipline offers impressive coverage of many OC hot topicsOCO of modern astrophysics and cosmology, such as the origin of galactic and extragalactic cosmic rays, particle acceleration and radiation processes under extreme astrophysical conditions, and the search for dark matter."

Download or read book BL LAC X Ray Spectra written by and published by . This book was released on 2004 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Observations of Hard X rays from Extragalactic Objects written by Richard Fred Mushotzky and published by . This book was released on 1976 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Populations of High Energy Sources in Galaxies IAU S230 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2006-06-15 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the last 40 years astronomers have observed sources of intense X-ray radiation from beyond our Solar System. These have been associated with remarkable objects, such as neutron stars and black holes. Current satellite observatories have enabled us to extend the studies of these objects from the Milky Way and Magellanic Clouds to individual X-ray sources in other galaxies. At the same time, imaging facilities at gamma-rays and TeV energies have improved enormously, leading to many further discoveries within our own galaxy. This Symposium presents an overview of these new developments, covering detailed studies of individual sources within the Milky Way, global descriptions of X-ray source populations in other galaxies, and less resolved relatives at high redshift. Galaxy nuclei and diffuse emission components are included, as are new discoveries at gamma-rays and TeV energies. IAU S230 is a valuable resource for astronomers and graduates working in high-energy astrophysics.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: