Two 100-Mpc-scale structures in the three-dimensional distribution of radio galaxies and their implications     

Kate Brand  Steve Rawlings  Gary J. Hill  Mark Lacy  Ewan Mitchell  Joe Tufts 《Monthly notices of the Royal Astronomical Society》2003,344(1):283-306

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The host galaxies of active galactic nuclei   总被引：2，自引：0，他引：2  

Guinevere Kauffmann  Timothy M. Heckman  Christy Tremonti  Jarle Brinchmann  Stéphane Charlot  Simon D. M. White  Susan E. Ridgway  Jon Brinkmann  Masataka Fukugita  Patrick B. Hall  &#;eljko Ivezi&#;  Gordon T. Richards  Donald P. Schneider 《Monthly notices of the Royal Astronomical Society》2003,346(4):1055-1077

We examine the properties of the host galaxies of 22 623 narrow-line active galactic nuclei (AGN) with  0.02 < z < 0.3  selected from a complete sample of 122 808 galaxies from the Sloan Digital Sky Survey. We focus on the luminosity of the [O  iii ]λ5007 emission line as a tracer of the strength of activity in the nucleus. We study how AGN host properties compare with those of normal galaxies and how they depend on L [O  iii ]. We find that AGN of all luminosities reside almost exclusively in massive galaxies and have distributions of sizes, stellar surface mass densities and concentrations that are similar to those of ordinary early-type galaxies in our sample. The host galaxies of low-luminosity AGN have stellar populations similar to normal early types. The hosts of high-luminosity AGN have much younger mean stellar ages. The young stars are not preferentially located near the nucleus of the galaxy, but are spread out over scales of at least several kiloparsecs. A significant fraction of high-luminosity AGN have strong Hδ absorption-line equivalent widths, indicating that they experienced a burst of star formation in the recent past. We have also examined the stellar populations of the host galaxies of a sample of broad-line AGN. We conclude that there is no significant difference in stellar content between type 2 Seyfert hosts and quasars (QSOs) with the same [O  iii ] luminosity and redshift. This establishes that a young stellar population is a general property of AGN with high [O  iii ] luminosities.  相似文献   

XMM–Newton confirmation of a warm absorber in the z = 4.4 blazar PMN J0525−3343     

M. A. Worsley  A. C. Fabian  A. K. Turner  A. Celotti  K. Iwasawa 《Monthly notices of the Royal Astronomical Society》2004,350(1):207-212

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XMM–Newton spectral properties of the narrow-line Seyfert 1 galaxy IRAS 13224 – 3809     

Th. Boller  Y. Tanaka  A. Fabian  W. N. Brandt  L. Gallo  N. Anabuki  Y. Haba  S. Vaughan 《Monthly notices of the Royal Astronomical Society》2003,343(4):L89-L93

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A high-velocity ionized outflow and XUV photosphere in the narrow emission line quasar PG1211+143   总被引：1，自引：0，他引：1  

K. A. Pounds  J. N. Reeves  A. R. King  K. L. Page  P. T. O'Brien  M. J. L. Turner 《Monthly notices of the Royal Astronomical Society》2003,345(3):705-713

We report on the analysis of a ∼60-ks XMM–Newton observation of the bright, narrow emission line quasar PG1211+143. Absorption lines are seen in both European Photon Imaging Camera and Reflection Grating Spectrometer spectra corresponding to H- and He-like ions of Fe, S, Mg, Ne, O, N and C. The observed line energies indicate an ionized outflow velocity of ∼24 000 km s⁻¹. The highest energy lines require a column density of   N _H∼ 5 × 10²³ cm⁻²  , at an ionization parameter of  log ξ∼ 3.4  . If the origin of this high-velocity outflow lies in matter being driven from the inner disc, then the flow is likely to be optically thick within a radius of ∼130 Schwarzschild radii, providing a natural explanation for the big blue bump (and strong soft X-ray) emission in PG1211+143.  相似文献   

The ELAIS deep X-ray survey – I. Chandra source catalogue and first results     

J. C. Manners †  O. Johnson  O. Almaini  C. J. Willott  E. Gonzalez-Solares  A. Lawrence  R. G. Mann  I. Perez-Fournon  J. S. Dunlop  R. G. McMahon  S. J. Oliver  M. Rowan-Robinson  S. Serjeant 《Monthly notices of the Royal Astronomical Society》2003,343(1):293-305

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A Chandra observation of the X-ray environment and jet of 3C 296     

M. J. Hardcastle  D. M. Worrall  M. Birkinshaw  R. A. Laing  A. H. Bridle 《Monthly notices of the Royal Astronomical Society》2005,358(3):843-850

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Infrared observations of serendipitous hard Chandra X-ray sources     

C. S. Crawford  A. C. Fabian  P. Gandhi  R. J. Wilman  R. M. Johnstone 《Monthly notices of the Royal Astronomical Society》2001,324(2):427-442

We present observations of a sample of optically faint, hard X-ray sources of the kind likely to be responsible for much of the hard X-ray background. We confirm that such sources are easily detected in the near-infrared, and find that they have a featureless continuum suggesting that the active nucleus is heavily obscured. The infrared colours of the majority of the targets observed are consistent with absorbed elliptical host galaxies at z =1–2. It is likely that we are observing some of the brighter members of the important new class of X-ray type II quasars.  相似文献   

The relationship between X-ray variability amplitude and black hole mass in active galactic nuclei     

Paul M. O'Neill  Kirpal Nandra  Iossif E. Papadakis  T. J. Turner 《Monthly notices of the Royal Astronomical Society》2005,358(4):1405-1416

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The unresolved hard X-ray background: the missing source population implied by the Chandra and XMM–Newton deep fields     

M. A. Worsley  A. C. Fabian  F. E. Bauer  D. M. Alexander  G. Hasinger  S. Mateos  H. Brunner  W. N. Brandt  D. P. Schneider 《Monthly notices of the Royal Astronomical Society》2005,357(4):1281-1287

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