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Browsing by Subject "Active galactic nuclei"
Now showing items 1-20 of 25
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(Oxford University Press, 2013-07)1ES 1927+654 is an active galactic nucleus (AGN) that appears to defy the unification model. It exhibits a type-2 optical spectrum, but possesses little X-ray obscuration. XMM–Newton and Suzaku ...
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(Oxford University Press, 2013-05)A recent approach to simulating localized feedback from active galactic nuclei (AGN) by Power et al. uses an accretion disc particle to represent both the black hole and its accretion disc. We have extrapolated and adapted ...
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(Oxford University Press, 2014-09-21)The X-ray spectra of the narrow-line Seyfert 1 galaxy, 1H 0707–495, obtained with XMM–Newton, from time periods of varying X-ray luminosity are analysed in the context of understanding the changes to the X-ray ...
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(Oxford University Press, 2013-05)Modelling active galactic nuclei (AGN) feedback in numerical simulations is both technically and theoretically challenging, with numerous approaches having been published in the literature. We present a study of five ...
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(Oxford University Press, 2015-03-21)We consider the Comptonization of the photons that make up the relativistically blurred reflection that is commonly detected from the accretion discs of active galactic nuclei by the coronae of energetic particles believed ...
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(Halifax, N.S. : Saint Mary's University, 2011)The XMM-Newton Observatory has conducted many observations of the type I active galactic nucleus 1H0707-495. The 0.7 deg [superscript 2] field of view around the AGN was observed over the course of ∼10 years with a total ...
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(American Astronomical Society, 2015-02-20)SDSS J015957.64+003310.5 is an X-ray selected, z = 0.31 active galactic nucleus (AGN) from the Stripe 82X survey that transitioned from a Type 1 quasar to a Type 1.9 AGN between 2000 and 2010. This is the most distant AGN, ...
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(Halifax, N.S. : Saint Mary's University, 2017)The differences in emissivity profiles produced by various corona geometries are explored via general relativistic ray tracing simulations in order to better understand the inner disc region of active galactic nuclei. ...
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(Halifax, N.S. : Saint Mary's University, 2013)Feedback from active galactic nuclei is now widely regarded as playing a fundamental role in modern theories of galaxy formation. Recent research has highlighted that not only may AGN feedback suppress star formation by ...
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(Oxford University Press, 2016-05-11)Being one of only two fundamental properties black holes possess, the spin of supermassive black holes (SMBHs) is of great interest for understanding accretion processes and galaxy evolution. However, in these early days ...
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(Halifax, N.S. : Saint Mary's University, 2019)X-ray observations of two Seyfert AGN were analysed in an effort to characterise the nature of their variability. A spectral analysis was performed on a Suzaku observation of the Seyfert 1.5 AGN Mrk 530, and a timing ...
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(Oxford University Press, 2014-01-13)The recent detection of X-ray reverberation lags, especially in the Fe Kα line region, around active galactic nuclei (AGN) has opened up the possibility of studying the time-resolved response (reflection) of hard ...
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(Oxford University Press, 2019-01-25)A number of works point to the presence of narrow emission features at unusual energies in the X-ray spectra of active galactic nuclei or to potentially low iron abundances as possible evidence for the spallation of iron. ...
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(Oxford University Press, 2014-09-11)We present 3–50 keV NuSTAR observations of the active galactic nuclei Mrk 335 in a very low flux state. The spectrum is dominated by very strong features at the energies of the iron line at 5–7 keV and Compton ...
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The origin of blueshifted absorption features in the X-ray spectrum of PG 1211+143: outflow or disc (Oxford University Press, 2013-09)In some radio-quiet active galactic nuclei (AGN), high-energy absorption features in the X-ray spectra have been interpreted as ultrafast outflows (UFOs) – highly ionized material (e.g. Fe XXV and Fe XXVI) ejected at mildly ...
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(Halifax, N.S. : Saint Mary's University, 2021)High-velocity outflows in active galactic nuclei usually manifest as either a collimated jet or diffuse wind. These outflows carry a significant amount of energy from the central environment surrounding the supermassive ...
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(Halifax, N.S. : Saint Mary's University, 2015)Numerical modeling of active galactic nuclei (AGN) poses many challenges, from uncertainties about the underlying physics to dynamic range issues. We present a study of simulated activity functions (AF; the differential ...
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(Oxford University Press, 2016-05-11)The cosmic X-ray background (CXB) is the total emission from past accretion activity on to supermassive black holes in active galactic nuclei (AGN) and peaks in the hard X-ray band (30 keV). In this paper, we identify a ...
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(Halifax, N.S. : Saint Mary's University, 2013)A search for relativistically blurred Fe-L [alpha] is performed on 353 nearby broad and narrow line Type-1 active galactic nuclei (AGN). Simple phenomenological modeling is applied to establish the presence of Fe-L[alpha] ...
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(Oxford University Press, 2015-01)We report on the deepest X-ray observation of the narrow-line Seyfert 1 galaxy Mrk 335 in the low-flux state obtained with Suzaku. The data are compared to a 2006 high-flux Suzaku observation when the source was ∼10 times ...
Now showing items 1-20 of 25