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 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 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 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 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 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 BL Lac Phenomenon written by Leo O. Takalo and published by . This book was released on 1999 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 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 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 X ray Emission from Active Galactic Nuclei written by Richard Mushotzky and published by . This book was released on 1985 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Variable X ray Spectra of BL LAC Objects HEAO 1 Observations of PKS 0548 322 and 2A 1219 305 written by Diana M. Worrall and published by . This book was released on 1980 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book X Ray Astronomy written by G. Giacconi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains a series of lectures presented at the 5th Course of the International School of Astrophysics held in Erice (Sicily) from July 1st to July 14, 1979 at the "E. Majorana" Centre for Scientific Culture. The course was fully supported by a grant from the NATO Advanced Institute Programme. It was attended by about one hundred participants from ten countries. Since the discovery of the first extra-solar X-ray source in the early 1960's, X-ray astronomy has played an increasingly important role in the study of the Universe, bringing new insight to almost every field of modern astrophysics from stellar evolution to cosmology. Generally speaking, this branch of astronomy is concerned with the discovery, classification and study of "hot matter" in the universe, including high energy non-thermal pheno mena. In particular, X-ray observations appear to provide the main, if not the only, probe to inspect regions where collapsed objects are formed, such as the environment of neutron stars and of black holes in the presence of matter accretion onto the objects themselves. It is significant that the first candidate black hole (Cyg X-I) has been primarily singled out by its X-ray emission. In the same context, it is well known that one of the fundamental problems in modern astrophysics is the understanding of the strong activity taking place in galactic nuclei.
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 X ray and Ultra violet Observations of BL Lacertae Type Objects written by Ian Michael George and published by . This book was released on 1988 with total page 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 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1987 with total page 1284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
