Now showing items 1-13 of 13

    • Correlated X-ray/optical variability in the quasar MR 2251-178 

      Arévalo, P.; Uttley, P.; Kaspi, S.; Breedt, E.; Lira Teillery, Paulina; McHardy, I. M. (BLACKWELL, 2008-09-21)
      Emission from active galactic nuclei is known to vary strongly over time over a wide energy band, but the origin of the variability and especially of the interband correlations is still not well established. Here we present ...
    • Correlated X-ray/ultraviolet/optical variability in the very low mass AGN NGC 4395 

      Cameron, D. T.; McHardy, I.; Dwelly, T.; Breedt, E.; Uttley, P.; Lira Teillery, Paulina; Arévalo, P. (WILEY-BLACKWELL, 2012-05)
      We report the results of a 1-yr Swift X-ray/ultraviolet (UV)/optical programme monitoring the dwarf Seyfert nucleus in NGC4395 in 2008–2009. The UV/optical flux from the nucleus was found to vary dramatically over the ...
    • Correlation and time delays of the X-ray and optical emission of the Seyfert Galaxy NGC 3783 

      Arévalo, P.; Uttley, P.; Lira Teillery, Paulina; Breedt, E.; McHardy, I. M.; Churazov, E. (WILEY-BLACKWELL, 2009-08-21)
      We present simultaneous X-ray and optical B- and V-band light curves of the Seyfert Galaxy NGC 3783 spanning 2 years. The flux in all bands is highly variable and the fluctuations are significantly correlated. As shown ...
    • Long-term monitoring of the archetype Seyfert galaxy MCG-6-30-15: X-ray, optical and near-IR variability of the corona, disc and torus 

      Lira Teillery, Paulina; Arevalo, P.; Uttley, P.; McHardy, I.; Videla, L. (Royal Astronomical Society, 2015)
      We present long-term monitoring of MCG-6-30-15 in X-rays, optical and near-IR wavelengths, collected over 5 yr of monitoring. We determine the power spectrum density of all the observed bands and show that after taking ...
    • Optical and near-IR long-term monitoring of NGC 3783 and MR 2251−178: evidence for variable near-IR emission from thin accretion discs 

      Lira Teillery, Paulina; Arévalo, P.; Uttley, P.; McHardy, I.; Breedt, E. (WILEY-BLACKWELL, 2011-08)
      We present the long-term near-IR light curves for two nearby active galactic nuclei (AGN), NGC 3783 and MR 2251−178. The near-IR data are complemented by optical photometry obtained over the same period of time. The light ...
    • Space telescope and optical reverberation mapping project. I. Ultraviolet observations of the seyfert 1 galaxy NGC 5548 with the cosmic origins spectrograph on hubble space telescope 

      Rosa, G. de; Peterson, B. M.; Ely, J.; Kriss, G. A.; Crenshaw, D. M.; Horne, Keith; Korista, K. T.; Netzer, H.; Pogge, R. W.; Arévalo, P.; Barth, A. J.; Bentz, M. C.; Brandt, W. N.; Breeveld, A. A.; Brewer, B. J.; Dalla Bontà, E.; Lorenzo Cáceres, A. de; Denney, K. D.; Dietrich, M.; Edelson, R.; Evans, P. A.; Fausnaugh, M. M.; Gehrels, N.; Gelbord, J. M.; Goad, M. R.; Grier, C. J.; Grupe, D.; Hall, P. B.; Kaastra, J.; Kelly, B. C.; Kennea, J. A.; Kochanek, C. S.; Lira Teillery, Paulina; Mathur, S.; McHardy, I. M.; Nousek, J. A.; Pancoast, A.; Papadakis, I.; Pei, L.; Schimoia, J. S.; Siegel, M.; Starkey, D.; Treu, T.; Uttley, P.; Vaughan, S.; Vestergaard, M.; Villforth, C.; Yan, H.; Young, S.; Zu, Y. (IOP Publishing, 2015)
      We describe the first results from a six-month long reverberation-mapping experiment in the ultraviolet based on 171 observations of the Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on the Hubble Space ...
    • Space telescope and optical reverberation mapping project. II. Swift and hst reverberation mapping of the accretion disk of NGC 5548 

      Edelson, R.; Gelbord, J. M.; Horne, K.; McHardy, I. M.; Peterson, B. M.; Arévalo, P.; Breeveld, A. A.; Rosa, G. de; Evans, P. A.; Goad, M. R.; Kriss, G. A.; Brandt, W.N.; Gehrels, N.; Grupe, D.; Kennea, J. A.; Kochanek, C. S.; Nousek, J. A.; Papadakis, I.; Siegel, M.; Starkey, D.; Uttley, P.; Vaughan, S.; Young, S.; Barth, A. J.; Bentz, M. C.; Brewer, B. J.; Crenshaw, D. M.; Dalla Bontà, E.; Lorenzo Cáceres, A. de; Denney, K. D.; Dietrich, M.; Ely, J.; Fausnaugh, M. M.; Grier, C. J.; Hall, P. B.; Kaastra, J.; Kelly, B. C.; Korista, K. T.; Lira Teillery, Paulina; Mathur, S.; Netzer, H.; Pancoast, A.; Pei, L.; Pogge, R. W.; Schimoia, J. S.; Treu, T.; Vestergaard, M.; Villforth, C.; Yan, H.; Zu, Y. (IOP Publishing, 2015)
      Recent intensive Swift monitoring of the Seyfert 1 galaxy NGC 5548 yielded 282 usable epochs over 125 days across six UV/optical bands and the X-rays. This is the densest extended active galactic nucleus (AGN) UV/optical ...
    • Space telescope and optical reverberation mapping project. III optical continuum emission and broadband time delays in ngc 5548 

      Fausnaugh, M. M.; Denney, K. D.; Barth, A. J.; Bentz, M. C.; Bottorff, M. C.; Carini, M. T.; Croxall, K. V.; Rosa, G. de; Goad, M. R.; Horne, Keith; Joner, M. D.; Kaspi, S.; Kim, M.; Klimanov, S. A.; Kochanek, C. S.; Leonard, D. C.; Netzer, H.; Peterson, B. M.; Schnulle, K.; Sergeev, S. G.; Vestergaard, M.; Zheng, W.-K; Zu, Y.; Anderson, M. D.; Arévalo, P.; Bazhaw, C.; Borman, G. A.; Boroson, T. A.; Brandt, W. N.; Breeveld, A. A.; Brewer, B. J.; Cackett, E. M.; Crenshaw, D. M.; Dalla Bonta, E.; Lorenzo Cáceres, A. de; Dietrich, M.; Edelson, R.; Efimova, N. V.; Ely, J.; Evans, P. A.; Filippenko, A. V.; Flatland, K.; Gehrels, N.; Geier, S.; Gelbord, J. M.; González, L.; Gorjian, V.; Grier, C. J.; Grupe, D.; Hall, P. B.; Hicks, S.; Horenstein, D.; Hutchison, T.; Im, M.; Jensen, J. J.; Jones, J.; Kaastra, J.; Kelly, B. C.; Kennea, J. A.; Kim, S. C.; Korista, K. T.; Kriss, G. A.; Lee, J. C.; Lira Teillery, Paulina; MacInnis, F.; Manne-Nicholas, E. R.; McHardy, I. M.; Montouri, C.; Musso, R.; Nazarov, S. V.; Norris, R. P.; Nousek, J. A.; Okhmat, D. N.; Pancoast, A.; Papadakis, I.; Parks, J. R.; Pei, L.; Pogge, R. W.; Pott, J.-U; Rafter, S. E.; Rix, H. -W.; Saylor, D. A.; Schimoia, J. S.; Siegel, M.; Spencer, M.; Starkey, D.; Sung, H. -I.; Teems, K. G.; Treu, T.; Turner, C. S.; Uttley, P.; Villforth, C.; Weiss, Y.; Woo, J. -H; Yan, H.; Young, S. (IOP Publisihing, 2016)
      We present ground-based optical photometric monitoring data for NGC 5548, part of an extended multiwavelength reverberation mapping campaign. The light curves have nearly daily cadence from 2014 January to July in ...
    • Space telescope and optical reverberation mapping project. iv. anomalous behavior of the broad ultraviolet emission lines in ngc 5548 

      Goad, M. R.; Korista, K. T.; De Rosa, G.; Kriss, G. A.; Edelson, R.; Barth, A. J.; Ferland, G. J.; Kochanek, C. S.; Netzer, H.; Peterson, B. M.; Bentz, M. C.; Bisogni, S.; Crenshaw, D. M.; Denney, K. D.; Ely, J.; Fausnaugh, M. M.; Grier, C. J; Gupta, A.; Horne, K. D.; Kaastra, J.; Pancoast, A.; Pei, L.; Pogge, R. W.; Skielboe, A.; Kaastra, J.; Pancoast, A.; Pei, L.; Pogge, R. W.; Skielboe, A.; Starkey, D.; Vestergaard, M.; Zu, Y.; Anderson, M. D.; Arévalo, P.; Bazhaw, C.; Borman, G. A.; Boroson, T. A.; Bottorff, M. C.; Brandt, W. N.; Breeveld, A. A.; Brewer, B. J.; Cackett, E. M.; Carini, M. T.; Croxall, K. V.; Dalla Bonta, E.; De Lorenzo Cáceres, A.; Dietrich, M.; Efimova, N. V.; Evans, P. A.; Filippenko, A. V.; Flatland, K.; Gehrels, N.; Geier, S.; Gelbord, J. M.; González, L.; Gorjian, V.; Grupe, D.; Hall, P. B.; Hicks, S.; Horenstein, D.; Hutchison, T.; Im, M.; Jensen, J. J.; Joner, M. D.; Jones, J.; Kaspi, S.; Kelly, B. C.; Kennea, J. A.; Kim, M.; Kim, S. C.; Klimanov, S. A.; Lee, J. C.; Leonard, D. C.; Lira Teillery, Paulina; MacInnis, F.; Manne-Nicholas, E. R.; Mathur, S.; McHardy, I. M.; Montouri, C.; Musso, R.; Nazarov, S. V.; Norris, R. P.; Nousek, J. A.; Okhmat, D. N.; Papadakis, I.; Parks, J. R.; Pott, J. U.; Rafter, S. E.; Rix, H. W.; Saylor, D. A.; Schimoia, J. S; Schnuelle, K.; Sergeev, S. G.; Siegel, M.; Spencer, M.; Sung, H. I.; Teems, K. G.; Treu, T.; Turner, C. S.; Uttley, P.; Villforth, C.; Weiss, Y.; Woo, J. H.; Yan, H.; Young, S.; Zheng, W. K. (IOP Publishing, 2016)
      During an intensive Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) UV monitoring campaign of the Seyfert 1 galaxy NGC 5548 performed from 2014 February to July, the normally highly correlated far UV continuum ...
    • Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-line Analysis for NGC 5548 

      Pei, L.; Fausnaugh, M. M.; Barth, A. J.; Peterson, B. M.; Bentz, M. C.; Rosa, G. de; Denney, K. D.; Goad, M. R.; Kochanek, C. S.; Korista, K. T.; Kriss, G. A.; Pogge, R. W.; Bennert, V. N.; Brotherton, M.; Clubb, K. I.; Dalla Bontà, E.; Filippenko, A. V.; Greene, J. E.; Grier, C. J.; Vestergaard, M.; Zheng, W.-K; Adams, Scott M.; Beatty, Thomas G.; Bigley, A.; Brown, Jacob E.; Brown, Jonathan S.; Canalizo, G.; Comerford, J. M.; Coker, Carl T.; Corsini, E. M.; Croft, S.; Croxall, K. V.; Deason, A. J.; Eracleous, Michael; Fox, O. D.; Gates, E. L.; Henderson, C. B.; Holmbeck, E.; Holoien, T. W.-S; Jensen, J. J.; Johnson, C. A.; Kelly, P. L.; Kim, S.; King, A.; Lau, M. W.; Li, Miao; Lochhaas, Cassandra; Ma, Zhiyuan; Manne-Nicholas, E. R.; Mauerhan, J. C.; Malkan, M. A.; McGurk, R.; Morelli, L.; Mosquera, Ana; Dale Mudd, Dale; Muller Sánchez, F.; Nguyen, M. L.; Ochner, P.; Ou-Yang, B.; Pancoast, A.; Penny, Matthew T.; Pizzella, A.; Poleski, Radoslaw; Runnoe, Jessie; Scott, B.; Schimoia, Jaderson S.; Shappee, B. J.; Shivvers, I.; Simonian, Gregory V.; Siviero, A.; Somers, Garrett; Stevens, Daniel J.; Strauss, M. A.; Tayar, Jamie; Tejos, Nicolás; Treu, T.; Van Saders, J.; Vican, L.; Villanueva, S.; Yuk, H.; Zakamska, N. L.; Zhu, W.; Anderson, M. D.; Arévalo, P.; Bazhaw, C.; Bisogni, S.; Borman, G. A.; Bottorff, M. C.; Brandt, W. N.; Breeveld, A. A.; Cackett, E. M.; Carini, M. T.; Crenshaw, D. M.; Lorenzo Cáceres, A. de; Dietrich, M.; Edelson, R.; Efimova, N. V.; Ely, J.; Evans, P. A.; Ferland, G. J.; Flatland, K.; Gehrels, N.; Geier, S.; Gelbord, J. M.; Grupe, D.; Gupta, A.; Hall, P. B.; Hicks, S.; Horenstein, D.; Horne, Keith; Hutchison, T.; Im, M.; Joner, M. D.; Jones, J.; Kaastra, J.; Kaspi, S.; Kelly, B. C.; Kennea, J. A.; Kim, M.; Kim, S. C.; Klimanov, S. A.; Lee, J. C.; Leonard, D. C.; Lira, P.; MacInnis, F.; Mathur, S.; McHardy, I. M.; Montouri, C.; Musso, R.; Nazarov, S. V.; Netzer, H.; Norris, R. P.; Nousek, J. A.; Okhmat, D. N.; Papadakis, I.; Parks, J. R.; Pott, J.-U.; Rafter, S. E.; Rix, H.-W.; Saylor, D. A.; Schnülle, K.; Sergeev, S. G.; Siegel, M.; Skielboe, A.; Spencer, M.; Starkey, D.; Sung, H.-I.; Teems, K. G.; Turner, C. S.; Uttley, P.; Villforth, C.; Weiss, Y.; Woo, J.-H.; Yan, H.; Young, S.; Zu, Y. (Institute of Physics Publishing, 2017)
      We present the results of an optical spectroscopic monitoring program targeting NGC 5548 as part of a larger multi-wavelength reverberation mapping campaign. The campaign spanned six months and achieved an almost daily ...
    • Swift monitoring of NGC 5548: X-ray reprocessing and short-term UV/optical variability 

      McHardy, I. M.; Cameron, D. T.; Dwelly, T.; Connolly, S.; Lira Teillery, Paulina; Emmanoulopoulos, D.; Gelbord, J.; Breedt, E.; Arevalo, P.; Uttley, P. (Royal Astronomical Society, 2014)
      Lags measured from correlated X-ray/UV/optical monitoring of AGN allow us to determine whether UV/optical variability is driven by reprocessing of X-rays or X-ray variability is driven by UV/optical seed photon variations. ...
    • Twelve years of X-ray and optical variability in the Seyfert galaxy NGC 4051 

      Breedt, E.; McHardy, I. M.; Arévalo, P.; Uttley, P.; Sergeev, S. G.; Minezaki, T.; Yoshii, Y.; Sakata, Y.; Lira Teillery, Paulina; Chesnok, N. G. (2009)
      We discuss the origin of the optical variations in the Narrow line Seyfert 1 galaxy NGC 4051 and present the results of a cross-correlation study using X-ray and optical light curves spanning more than 12 years. The ...
    • X-ray/UV/optical variability of NGC 4593 with Swift: Reprocessing of X-rays by an extended reprocessor 

      McHardy, I. M.; Connolly, S. D.; Horne, K.; Cackett, E. M.; Gelbord, J.; Peterson, B. M.; Pahari, M.; Gehrels, N.; Goad, M.; Lira, P.; Arevalo, P.; Baldi, R. D.; Brandt, N.; Breedt, E.; Chand, H.; Dewangan, G.; Done, C.; Elvis, M.; Emmanoulopoulos, D.; Fausnaugh, M. M.; Kasp (Oxford University Press, 2018)
      © 2018 The Author(s). We report the results of intensive X-ray, UV, and optical monitoring of the Seyfert 1 galaxy NGC 4593 with Swift. There is no intrinsic flux-related spectral change in any variable component with small ...