Search

Now showing items 1-7 of 7

The X-ray and ultraviolet absorbing outflow in 3C 351

Mathur, Smita; Wilkes, Belinda Jane; Elvis, Martin S.; Fiore, Fabrizio (IOP Publishing, 1994)

3C 351 (z = 0.371), and X-ray-'quiet' quasar, is one of the few quasars showing signs of a 'warm absorber' in its X-ray spectrum; i.e., partially ionized absorbing material in the line of sight whose opacity depends on its ...

Absorption in X-ray spectra of high-redshift quasars

Elvis, Martin S.; Fiore, Fabrizio; Wilkes, Belinda Jane; McDowell, Jonathan Christopher; Bechtold, Jill (IOP Publishing, 1994)

We present evidence that X-ray absorption is common in high-redshift quasars. We have studied six high-redshift (z approximately 3) quasars with the ROSAT Position Sensitive Proportional Counter (PSPC) of which four are ...

The complex optical to soft x-ray spectrum of the low-redshift radio-quiet quasars

Fiore, Fabrizio; Elvis, Martin S.; McDowell, Jonathan Christopher; Siemiginowska, Aneta L.; Wilkes, Belinda Jane (IOP Publishing, 1994)

Eight high signal-to-noise ROSAT Position Sensitive Proportional Counter (PSPC) observations of six low-redshift (o.048 less than z less than 0.155) radio-quiet quasars have been analyzed to study ant soft excess. All the ...

Consistency of spherical, gravity-dominated dynamics with quasar high-ionization emission-line profiles

Kallman, T. R.; Wilkes, Belinda Jane; Krolik, J. H.; Green, Richard (IOP Publishing, 1993)

Line profile data are used to test a simple kinematic model - spherically symmetric gravitational free fall - in which the number of free parameters is limited by requiring physical self-consistency. The predictions of ...

Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. II - an intensive study of NGC 5548 at optical wavelengths

Peterson, B. M.; Balonek, T. J.; Barker, E. S.; Bechtold, J.; Bertram, R.; Bochkarev, N. G.; Bolte, M. J.; Bond, D.; Boroson, T. A.; Carini, M. T.; Carone, T. E.; Christensen, J. A.; Clements, S. D.; Cochran, A. L.; Cohen, R. D.; Crampton, D.; Dietrich, M.; Elvis, Martin S.; Ferguson, A.; Filippenko, A. V.; Fricke, K. J.; Gaskell, C. M.; Halpern, J. P.; Huchra, J; Hutchings, J. B.; Kollatschny, W.; Koratkar, A. P.; Korista, K. T.; Krolik, J. H.; Lame, N. J.; Laor, A.; Leacock, R. J.; MacAlpine, G. M.; Malkan, M. A.; Maoz, D.; Miller, H. R.; Morris, S. L.; Netzer, H.; Oliveira, C. L. M.; Penfold, J.; Penston, M. V.; Perez, E.; Pogge, R. W.; Richmond, M. W.; Romanishin, W.; Rosenblatt, E. I.; Saddlemyer, L.; Sadun, A.; Sawyer, S. R.; Shields, J. C.; Shapovalova, A. I.; Smith, A. G.; Smith, H. A.; Smith, P. S.; Sun, W.-H.; Thiele, U.; Turner, T. J.; Veilleux, S.; Wagner, R. M.; Weymann, R. J.; Wilkes, Belinda Jane; Wills, B. J.; Wills, D.; Younger, P. F. (IOP Publishing, 1991)

A large, international program of ground-based optical spectroscopy and photometry of the variable Seyfert 1 galaxy NGC 5548 undertaken in support of an IUE monitoring campaign is described. This contribution presents the ...

Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. III - Further observations of NGC 5548 at optical wavelengths

Peterson, B. M.; Alloin, D.; Axon, D.; Balonek, T. J.; Bertram, R.; Boroson, T. A.; Christensen, J. A.; Clements, S. D.; Dietrich, M.; Elvis, Martin S.; Filippenko, A. V.; Gaskell, C. M.; Haswell, C. A.; Huchra, J; Jackson, N.; Kollatschny, W.; Korista, K. T.; Lame, N. J.; Leacock, R. J.; Lin, S.-N.; Malkan, M. A.; Monk, A. S.; Penston, M. V.; Pogge, R. W.; Robinson, A.; Rosenblatt, E. I.; Shields, J. C.; Smith, A. G.; Stirpe, G. M.; Sun, W.-H.; Turner, T. J.; Wagner, R. M.; Wilkes, Belinda Jane; Wills, B. J. (IOP Publishing, 1992)

The results of the second year of an intensive ground-based spectroscopic and photometric study of variability in the bright Seyfert 1 galaxy NGC 5548 are reported in order to study the relationship between continuum and ...

Steps toward determination of the size and structure of the broad-line region in active galactic nuclei. IV - Intensity variations of the optical emission lines of NGC 5548

Dietrich, M.; Kollatschny, W.; Peterson, B. M.; Bechtold, J.; Bertram, R.; Bochkarev, N. G.; Boroson, T. A.; Carone, T. E.; Elvis, Martin S.; Filippenko, A. V.; Gaskell, C. M.; Huchra, J; Hutchings, J. B.; Koratkar, A. P.; Korista, K. T.; Lame, N. J.; Laor, A.; MacAlpine, G. M.; Malkan, M. A.; Mendes de Oliveira, C.; Netzer, H.; Penfold, J.; Penston, M. V.; Perez, E.; Pogge, R. W.; Richmond, M. W.; Rosenblatt, E. I.; Shapovalova, A. I.; Shields, J. C.; Smith, H. A.; Smith, P. S.; Sun, W.-H.; Thiele, U.; Veilleux, S.; Wagner, R. M.; Wilkes, Belinda Jane; Wills, B. J.; Wills, D. (IOP Publishing, 1993)

Measurements of optical emission-line flux variations based on spectra of the Seyfert galaxy NGC 5548 obtained between December 1988 and October 1989 are reported. All of the measured optical emission lines, H-alpha, H-beta, ...