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Browsing Articles by Subject "Active galaxies"
Now showing items 1-20 of 22
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(Oxford University Press, 2013-01)As part of a long-term monitoring campaign of Mrk 335, deep XMM–Newton observations catch the narrow-line Seyfert 1 galaxy (NLS1) in a complex, intermediate flux interval as the active galaxy is transiting from low to high ...
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(Oxford University PressRoyal Astronomical Society, 2018-06-01)We collate active galactic nuclei (AGN) with reported detections of both relativistic reflection and ultrafast outflows. By comparing the inclination of the inner disc from reflection with the line-of-sight velocity of the ...
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(Oxford University Press, 2015-12-21)Monitoring of the narrowline Seyfert 1 galaxy Markarian 335 (Mrk 335) with the Swift satellite discovered an X-ray flare beginning 2014 August 29. At the peak, the 0.5–5 keV count rate had increased from that in the low-flux ...
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(Royal Astronomical Society and Oxford University Press, 1997)The ROSAT data from the cluster gas of Cygnus A are re-examined in light of a three-dimensional hydrodynamic simulation of a supersonic jet propagating in an isothermal King atmosphere designed to follow the observed density ...
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(IOP Publishing Limited, 2014-04-10)The X-ray spectra of many active galactic nuclei exhibit a “soft excess” below 1 keV, whose physical origin remains unclear. Diverse models have been suggested to account for it, including ionized reflection ...
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(Oxford University Press on behalf of the Royal Astronomical Society, 2011-11)Narrow absorption lines seen in the 2–10 keV spectra of active galaxies and Galactic black holes are normally attributed to iron in high-velocity outflows or inflows. We consider the possibility that such features could ...
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(Royal Astronomical SocietyOxford University Press, 2012)PHL 1092 is a z ∼ 0.4 high-luminosity counterpart of the class of Narrow-Line Seyfert 1 galaxies. In 2008, PHL 1092 was found to be in a remarkably low X-ray flux state during an XMM–Newton observation. Its 2 keV flux ...
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(Oxford University Press, 2015-06-11)A multi-epoch, multi-instrument analysis of the Seyfert 1 galaxy HE 0436–4717 is conducted using optical to X-ray data from XMM–Newton and Swift (including the Burst Alert Telescope). Fitting of the UV-to-X-ray spectral ...
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(Oxford University PressRoyal Astronomical Society, 2019-01-16)We present results from a deep, coordinated XMM–Newton + NuSTAR observation of the Seyfert 2 galaxy IRAS 00521−7054. The NuSTAR data provide the first detection of this source in ...
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(Oxford University Press, 2011-02)Multi-epoch X-ray spectroscopy (0.3–25 keV) of the Seyfert 1.2 galaxy Mrk 79 (UGC3973) spanning nearly 8 yr and a factor of 3 in broad-band flux are analysed. The data are obtained at seven epochs with either XMM–Newton ...
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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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(Royal Astronomical SocietyOxford University Press, 2009)We report a dramatic variability event in the X-ray history of the narrow-line quasar PHL 1092 (z = 0.396). Our latest 2008 XMM-Newton observation reveals a flux drop of ∼200 with respect to the previous observation performed ...
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(American Astronomical Society, 2012-04)The narrow-line Seyfert 1 galaxy (NLS1) Mkn 335 is remarkable because it has repeatedly shown deep, long X-ray low states that show pronounced spectral structure. It has become one of the prototype active galactic nuclei ...
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(American Astronomical SocietyIOP Publishing, 2013-04-01)We present the discovery of an outflowing ionized wind in the Seyfert 1 galaxy Mrk 335. Despite having been extensively observed by most of the largest X-ray observatories in the last decade, this bright source was not ...
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(Oxford University Press, 2015-09-09)We examine simultaneous X-ray and UV light curves from multi-epoch 8 d XMM–Newton observations of the narrow line Seyfert 1 galaxy 1H 0707–495. The simultaneous observations reveal that both X-ray and UV emission are ...
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(Oxford University Press, 2009-10)We present the results from a monitoring campaign of the Narrow-Line Seyfert 1 galaxy PG 1211+143. The object was monitored with ground-based facilities (UBVRI photometry; from 2007 February to July) and with Swift [X-ray ...
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(EDP Sciences, 2010-05)We present a Suzaku observation of the dwarf Seyfert galaxy NGC 4395 with an estimated black hole mass of ~105M[subscript circled dot]. Rapid and strong X-ray variability with an rms amplitude of ~60 per cent is observed ...
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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 ...
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(Oxford University Press on behalf of the Royal Astronomical Society, 2018-07-20)We present new XMM–Newton observations of the intriguing warm absorber in I Zwicky 1. This luminous and nearby narrow-line Seyfert 1 galaxy shows ionized absorption by two components of outflowing ...
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(Oxford University PressOxford University Press on behalf of the Royal Astronomical Society, 2018-04-04)We examine a 200 ks XMM–Newton observation of the narrow-line Seyfert 1 galaxy Mrk 493. The active galaxy was half as bright as in a previous 2003 snapshot observation ...
Now showing items 1-20 of 22