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Broad Lines (broad + line)
Selected AbstractsA short introduction to broad and variable iron lines around black holesASTRONOMISCHE NACHRICHTEN, Issue 10 2006A. C. Fabian Abstract Accreting black holes often show iron line emission in their X-ray spectra. When this line emission is very broad or variable then it is likely to originate from close to the black hole. The theory and observations of such broad and variable iron lines are briefly reviewed here. In order for a clear broad line to be found, one or more of the following have to occur: high iron abundance, dense disk surface and minimal complex absorption. Several excellent examples are found from observations of Seyfert galaxies and Galactic Black Holes. In several cases there is strong evidence that the black hole is rapidly spinning. Further examples are expected as more long observations are made with XMM-Newton, Chandra and Suzaku. Intriguing instances of rapid variability of some narrow iron lines, both emission and absorption, have been reported. These may reflect variations in the irradiation or motion of physical structures on the accretion disk. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Subtype selective kainic acid receptor agonists: Discovery and approaches to rational designMEDICINAL RESEARCH REVIEWS, Issue 1 2009Lennart Bunch Abstract (S)-Glutamic acid (Glu) is the major excitatory neurotransmitter in the mammalian central nervous system, activating the plethora of glutamate receptors (GluRs). In broad lines, the GluRs are divided into two major classes: the ionotropic Glu receptors (iGluRs) and the metabotropic Glu receptors (mGluRs). Within the iGluRs, five subtypes (KA1, KA2, iGluR5-7) show high affinity and express full agonist activity upon binding of the naturally occurring amino acid kainic acid (KA). Thus these receptors have been named the KA receptors. This review describes all,to our knowledge,published KA receptor agonists. In total, over 100 compounds are described by means of chemical structure and available pharmacological data. With this perspective review, it is our intention to ignite and stimulate inspiration for future design and synthesis of novel subtype selective KA receptor agonists. © 2008 Wiley Periodicals, Inc. Med Res Rev, 29, No. 1, 3,28, 2009 [source] GEMINI 3D spectroscopy of BAL + IR + Fe ii QSOs , I. Decoupling the BAL, QSO, starburst, NLR, supergiant bubbles and galactic wind in Mrk 231MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2009S. Lipari ABSTRACT In this paper we present the first results of a study of BAL QSOs (at low and high redshift), based on very deep Gemini GMOS integral field spectroscopy. In particular, the results obtained for the nearest BAL IR,QSO Mrk 231 are presented. For the nuclear region of Mrk 231, the QSO and host galaxy components were modelled, using a new technique of decoupling 3D spectra. From this study, the following main results were found: (i) in the pure host galaxy spectrum an extreme nuclear starburst component was clearly observed, as a very strong increase in the flux, at the blue wavelengths; (ii) the BAL system I is observed in the spectrum of the host galaxy; (iii) in the clean/pure QSO emission spectrum, only broad lines were detected. 3D GMOS individual spectra (specially in the near-infrared Ca ii triplet) and maps confirm the presence of an extreme and young nuclear starburst (8 < age < 15 Myr), which was detected in a ring or toroid with a radius r= 0.3 arcsec , 200 pc, around the core of the nucleus. The extreme continuum blue component was detected only to the south of the core of the nucleus. This area is coincident with the region where we previously suggested that the galactic wind is cleaning the nuclear dust. Very deep 3D spectra and maps clearly show that the BAL systems I and II , in the strong ,absorption lines' Na iD,5889,95 and Ca ii K,3933 , are extended (reaching ,1.4,1.6 arcsec , 1.2,1.3 kpc, from the nucleus) and clearly elongated at the position angle (PA) close to the radio jet PA, which suggest that the BAL systems I and II are ,both' associated with the radio jet. The physical properties of the four expanding nuclear bubbles were analysed, using the GMOS 3D spectra and maps. In particular, we found strong multiple LINER/OF emission-line systems and Wolf,Rayet features in the main knots of the more external super bubble S1 (r= 3.0 kpc). The kinematics of these knots , and the internal bubbles , suggest that they are associated with an area of rupture of the shell S1 (at the south-west). In addition, in the more internal superbubble S4 and close to the core of the nucleus (for r < 0.7 arcsec , 0.6 kpc), two similar narrow emission-line systems were detected, with strong [S ii] and [O i] emission and ,V,,200 km s,1. These results suggest that an important part of the nuclear NLR is generated by the OF process and the associated low-velocity ionizing shocks. Finally, the nature of the composite BAL systems and very extended OF process , of 50 kpc , in Mrk 231 (and similar QSOs) are discussed. In addition, the ,composite hyperwind scenario' (already proposed for BALs) is suggested for the origin of giant Ly, blobs. The importance of study the end phases of Mrk 231, and similar evolving elliptical galaxies and QSOs (i.e. galaxy remnants) is discussed. [source] The symbiotic system CH Cygni: An analysis of the shocked nebulae at different epochsASTRONOMISCHE NACHRICHTEN, Issue 8 2009M. Contini Abstract We analyse the line and continuum spectra of the symbiotic system CH Cygni. We adopt the colliding-wind model to explain the symbiotic system at different phases. Peculiar observed features such as flickering, radio variation, X-ray emission, as well as the distribution of the nebulae and shells throughout the system are investigated by modelling the spectra at different epochs. The models account consistently for shock and photoionization and are constrained by absolute fluxes. We find that the reverse shock between the stars leads to the broad lines observed during the active phases, as well as to radio and hard X-ray emission, while the expanding shock is invoked to explain the data particularly during the transition phases (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] | ||||||||||