Research Interests: Theory and Observations of Quasars, Active Galaxies, Supermassive Black Holes, and Supernovae

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2012

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DISCOVERY OF POLARIZATION REVERBERATION IN NGC 4151, C. Martin Gaskell, Reńe W. Goosmann, Nelly I. Merkulova, Nikolay M. Shakhovskoy, and Masatoshi Shoji

2008

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SETTING UBVRI PHOTOMETRIC ZERO-POINTS USING SLOAN DIGITAL SKY SURVEY ugriz MAGNITUDES, Taylor S. Chonis and C. Martin Gaskell

2007

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CHEMICAL ABUNDANCES IN AN AGN ENVIRONMENT: X-RAY/UV CAMPAIGN ON THE MARKARIAN 279 OUTFLOW, Nahum Arav, Jack R. Gabel, Kirk T. Korrista, Jelle S. Kaastra, Gerard A. Kriss, Ehud Behar, Elisa Constantini, C. Martin Gaskell, Ari Laor, C. Nalaka Kodituwakku, Daniel Proga, Masao Sako, Jennifer E. Scott, and Katrien C. Steenbrugge

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Transformations between 2MASS, SDSS and BVRI photometric systems: bridging the near infrared and optical, S. Bilir, S. Ak, S. Karaali, A. Cabrera-Lavers, T. S. Chonis, and C. Martin Gaskell

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Setting UBVRI Photometric Zero-Points Using Sloan Digital Sky Survey ugriz Magnitudes, Taylor S. Chonis and C. Martin Gaskell

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X-Ray/Ultraviolet Observing Campaign of the Markarian 279 Active Galactic Nucleus Outflow: a close look at the absorbing/emitting gas with Chandra-LETGS, E. Costantini, Jelle S. Kaastra, Nahum Arav, Gerard A. Kriss, K. C. Steenbrugge, Jack R. Gabel, F. Verbunt, Ehud Behar, C. Martin Gaskell, Kirk T. Korista, Daniel Proga, Jessica Kim-Quijano, J. E. Scott, Elizabeth S. Klimek, and C. H. Hedrick

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HUBBLE SPACE TELESCOPE ULTRAVIOLET SPECTROSCOPY OF 14 LOW-REDSHIFT QUASARS, Rajib Ganguly, Michael S. Brotherton, Nahum Arav, Sara R. Heap, Lutz Wisotzki, Thomas L. Aldcroft, Danielle Alloin, Ehud Behar, Gabriela Canalizo, D. Michael Crenshaw, Martijn De Kool, Kenneth Chambers, Gerald Cecil, Eleni Chatzichristou, John Everett, Jack R. Gabel, C. Martin Gaskell, Emmanuel Galliano, Richard F. Green, Patrick B. Hall, Dean C. Hines, Vesa T. Junkkarinen, Jelle S. Kaastra, Mary Elizabeth Kaiser, Demosthenes Kazanas, Arieh Konigl, Kirk T. Korista, Gerard A. Kriss, Ari Laor, Karen M. Leighly, Smita Mathur, Patrick Ogle, Daniel Proga, Bassem Sabra, Ran Sivron, Stephanie A. Snedden, Randal Telfer, and Marianne Vestergaard

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AGN REDDENING AND ULTRAVIOLET EXTINCTION CURVES FROM HUBBLE SPACE TELESCOPE SPECTRA, C. Martin Gaskell and C. Martin Gaskell

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DISCOVERY OF POLARIZATION REVERBERATION IN NGC 4151, C. Martin Gaskell, René W. Goosmann, Nelly I. Merkulova, Nikolay M. Shakhovskoy, and Masatoshi Shoji

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NGC 5548: THE AGN ENERGY BUDGET PROBLEM AND THE GEOMETRY OF THE BROAD-LINE REGION AND TORUS, C. Martin Gaskell, Elizabeth S. Klimek, and Ludmila S. Nazarova

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Modeling optical and UV polarization of AGNs I. Imprints of individual scattering regions, René W. Goosmann and C. Martin Gaskell

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AGN polarization modeling with STOKES, René W. Goosmann and C. Martin Gaskell

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Modeling optical and UV polarization of AGNsI. Imprints of individual scattering regions, René W. Goosmann and C. Martin Gaskell

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Modeling the Polarization of Dusty Scattering Cones in Active Galactic Nuclei, René W. Goosmann, C. Martin Gaskell, and Masatoshi Shoji

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THE CASE FOR OPTICALLY THICK HIGH-VELOCITY BROAD-LINE REGION GAS IN ACTIVE GALACTIC NUCLEI, Stephanie A. Snedden and C. Martin Gaskell

2006

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X-Ray/Ultraviolet Observing Campaign of the Markarian 279 Active Galactic Nucleus Outflow: a close look at the absorbing/emitting gas with Chandra-LETGS, E. Constantini, Jelle S. Kaastra, Nahum Arav, Gerard A. Kriss, K.C. Steenbrugge, Jack R. Gabel, F. Verbunt, Ehud Behar, C. Martin Gaskell, Kirk T. Korista, Daniel Proga, Jessica Kim-Quijano, J.E. Scott, Elizabeth S. Klimek, and C.H. Hedrick

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Hubble Space Telescope Ultraviolet Spectroscopy of Fourteen Low-Redshift Quasars, Rajib Ganguly, Michael S. Brotherton, Nahum Arav, Sara R. Heap, Lutz Wisotzki, Thomas L. Aldcroft, Danielle Alloin, Ehud Behar, Gabriela Canalizo, D. Michael Crenshaw, Martijn de Kool, Kenneth Chambers, Gerald Cecil, Eleni Chatzichristou, John Everett, Jack R. Gabel, C. Martin Gaskell, Emmanuel Galliano, Richard F. Green, Patrick B. Hall, Dean C. Hines, Vesa T. Junkkarinen, Jelle S. Kaastra, Mary Elizabeth Kaiser, Demosthenes Kazanas, Arieh Konigl, Kirk T. Korista, Gerard A. Kriss, Ari Laor, Karen M. Leighly, Smita Mathur, Patrick Ogle, Daniel Ogle, Bassem Sabra, Ran Sivron, Stephanie A. Snedden, Randal Telfer, and Marianne Vestergaard

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Optical and X-ray Variability of AGNs, C. Martin Gaskell

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The Origin of Wavelength-Dependent Continuum Delays in AGNs – a New Model, C. Martin Gaskell

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Optical Variability of the Three Brightest Nearby Quasars, C. Martin Gaskell, Andrew J. Benker, Jeffrey S. Campbell, Thomas A. George, Cecilia H. Hedrick, Mary E. Hiller, Elizabeth S. Klimek, Joseph P. Leonard, Shoji Masatoshi, Bradley W. Peterson, Kelly S. Peterson, and Kelly M. Sanders

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Evidence for Two Kinematically Distinct Broad Emission Line Producing Regions in Active Galactic Nuclei, Stephanie A. Snedden and C. Martin Gaskell

2005

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X-RAY/ULTRAVIOLET OBSERVING CAMPAIGN OF THE MARKARIAN 279 ACTIVE GALACTIC NUCLEUS OUTFLOW: A GLOBAL-FITTING ANALYSIS OF THE ULTRAVIOLET ABSORPTION, Jack R. Gabel, Nahum Arav, Jelle S. Kaastra, Gerard A. Kriss, Ehud Behar, Elisa Costantini, C. Martin Gaskell, Kirk T. Korista, Ari Laor, Frits Paerels, Daniel Proga, Jessica Kim-Quijano, Masao Sako, Jennifer E. Scott, and Katrien C. Steenbrugge

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Modelling continuum optical and ultraviolet polarization of active galactic nuclei, René W. Goosmann and C. Martin Gaskell

2004

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LOGNORMAL X-RAY FLUX VARIATIONS IN AN EXTREME NARROW-LINE SEYFERT 1 GALAXY, C. Martin Gaskell

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THE NUCLEAR REDDENING CURVE FOR ACTIVE GALACTIC NUCLEI AND THE SHAPE OF THE INFRARED TO X-RAY SPECTRAL ENERGY DISTRIBUTION, C. Martin Gaskell, René W. Goosmann, Robert R. J. Antonucci, and David H. Whysong

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OPTICAL VARIABILITY OF NARROW-LINE SEYFERT 1 GALAXIES, Elizabeth S. Klimek, C. Martin Gaskell, and Cecilia H. Hedrick

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Different Velocity Dependences of Physical Conditions of High- and Low-Ionization Lines in Broad-Line Regions, Stephanie A. Snedden and C. Martin Gaskell

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The Case for an Optically-Thick High-Velocity Broad-Line Region, Stephanie A. Snedden and C. Martin Gaskell

2001

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A spectroscopic and photometric study of short-timescale variability in NGC 5548, M. Dietrich, C. F. Bender, D. J. Bergmann, T. E. Bills, N. G. Bochkarev, A. Burenkov, C. Martin Gaskell, D. D. Gutzmer, R. Grove, M. E. Hiller, J. P. Huchra, Elizabeth S. Klimek, C. Lund, Nelly I. Merkulova, S. Pebley, Matt Poulsen, V. I. Pronik, S. G. Sergeev, E. A. Sergeeva, A. I. Shapovalova, V. V. Vlasyuk, and Belinda J. Wilkes

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MULTIWAVELENGTH MONITORING OF THE NARROW-LINE SEYFERT 1 GALAXY ARAKELIAN 564. III. OPTICAL OBSERVATIONS AND THE OPTICAL--UV--X-RAY CONNECTION, O. Shemmer, P. Romano, R. Bertram, W. Brinkmann, S. Collier, K. A. Crowley, E. Detsis, A. V. Filippenko, C. Martin Gaskell, T. A. George, M. Gliozzi, M. E. Hiller, T. L. Jewell, Shai Kaspi, Elizabeth S. Klimek, M. H. Lannon, W D. Li, P. Martini, Smita Mathur, H. Negoro, Hagai Netzer, Iossif Papadakis, Ioannis Papamastorakis, Bradley M. Peterson, Bradley W. Peterson, Richard William Pogge, V. I. Pronik, Kenneth S. Rumstay, S. G. Sergeev, G. M. Stirpe, C. J. Taylor, R. R. Treffers, T. J. Turner, P. Uttley, Marianne Vestergaard, Kaspar von Braun, R. M. Wagner, and Z. Zheng

2000

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A Look At What Is (And Isn't) Known About Quasar Broad Line Regions And How Narrow-Line Seyfert 1s Fit In, C. Martin Gaskell

1999

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THE EFFECT OF ABUNDANCE VARIATIONS ON ESTIMATES OF THE DENSITIES OF BROAD-LINE REGION CLOUDS IN QUASARS, Stephanie A. Snedden and C. Martin Gaskell

1998

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Steps Toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XIV. Intensive Optical Spectrophotometric Observations of NGC 7469, S.J. Collier, Keith Horne, Shai Kaspi, Hagai Netzer, Bradley M. Peterson, I. Wanders, T. Alexander, R. Bertram, A. Comastri, C. Martin Gaskell, Yu. F. Malkov, D. Maoz, M. Mignoli, Richard William Pogge, V.I. Pronik, S.G. Sergeev, Stephanie A. Snedden, G.M. Stirpe, N.G. Bochkarev, A.N. Burenkov, A.I. Shapovalova, and R.M. Wagner

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STEPS TOWARD DETERMINATION OF THE SIZE AND STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI. XII. GROUND-BASED MONITORING OF 3C 390.3, M. Dietrich, Bradley M. Peterson, P. Albrecht, M. Altmann, A.J. Barth, P.J. Bennie, R. Bertram, N.G. Bochkarev, H. Bock, J.M. Braun, A. Burenkov, S. Collier, L.-Z. Fang, O.P. Francis, A. V. Filippenko, C.B. Foltz, W. Gassler, C. Martin Gaskell, M. Geffert, K.K. Ghosh, R.W. Hilditch, R.K. Honeycutt, K. Horne, J.P. Huchra, Shai Kaspi, M. Kummel, K.M. Leighly, D.C. Leonard, Yu. F. Malkov, V. Mikhailov, H. Richard Miller, A.C. Morrill, J. Noble, Paul T. O'Brien, T.D. Oswalt, S.P. Pebley, M. Pfeiffer, V.I. Pronik, B.-C. Qian, J.W. Robertson, A. Robinson, Kenneth S. Rumstay, J. Schmoll, S.G. Sergeev, E.A. Sergeeva, A.I. Shapovalova, D.R. Skillman, Stephanie A. Snedden, S. Soundararajaperumal, G.M. Stirpe, J. Tao, G.W. Turner, R.M. Wagner, S.J. Wagner, J.Y. Wei, H. Wu, W. Zheng, and Z.L. Zhou

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STEPS TOWARD DETERMINATION OF THE SIZE AND STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI. XIII. ULTRAVIOLET OBSERVATIONS OF THE BROAD-LINE RADIO GALAXY 3C 390.3, Paul T. O'Brien, M. Dietrich, K. Leighly, D. Alloin, J. Clavel, D. Michael Crenshaw, K. Horne, G. A. Criss, Julian Henry Krolik, Matthew A. Malkan, Hagai Netzer, Bradley M. Peterson, G. A. Reichert, P. M. Rodriguez-Pascual, W. Wamsteker, K. S.J. Anderson, N. G. Bochkarev, F.-Z. Cheng, A. V. Filippenko, C. Martin Gaskell, I. M. George, M. R. Goad, L. C. Ho, Shai Kaspi, W. Kollatschny, Kirk T. Korista, G. MacAlpine, D. Marlow, P. G. Martin, S. L. Morris, Richard William Pogge, B. C. Qian, M. C. Recondo-Gonzalez, J. M. Rodriguez Espinosa, M. Santos-Lleo, A. I. Shapovalova, J. M. Shull, G. M. Stirpe, W.-H. Sun, T. J. Turner, R. Vio, S. Wagner, I. Wanders, K. A. Wills, H. Wu, S. J. Xue, and Z.-L. Zou

1997

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STEPS TOWARD DETERMINATION OF THE SIZE AND STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI. IX. ULTRAVIOLET OBSERVATIONS OF FAIRALL, P.M. Rodriguez-Pascual, D. Allion, J. Clavel, D. Michael Crenshaw, K. Horne, Gerard A. Kriss, Julian Henry Krolik, Matthew A. Malkan, Hagai Netzer, Paul T. O'Brien, Bradley M. Peterson, G.A. Reichert, W. Wamsteker, T. Alexander, P. Barr, R.D. Blandford, J.N. Bergman, T.E. Carone, S. Clements, T.-J. Courvoisier, M.M. De Robertis, M. Dietrich, H. Dottori, R.A. Edelson, A. V. Filippenko, C. Martin Gaskell, J. P. Huchra, J.B. Hutchings, W. Kollatschny, A.P. Koratkar, Kirk T. Korista, Ari Laor, G.M. MacAlpine, P.G. Martin, D. Maoz, B. McCollum, S.L. Morris, G.C. Perola, Richard William Pogge, R.L. Ptak, M.C. Recondo-Gonzalez, J.M. Rodriguez-Espinoza, E.L. Rokaki, M. Santos-Lleo, K. Sekiguchi, J.M. Schull, M.A.J. Snuders, L.S. Sparke, G.M. Stirpe, R.E. Stoner, W.-H. Sun, S.J. Wagner, I. Wanders, Belinda J. Wilkes, C. Winge, and W. Zheng

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STEPS TOWARD DETERMINATION OF THE SIZE AND STRUCTURE OF THE BROAD-LINE REGION IN ACTIVE GALACTIC NUCLEI. XI. INTENSIVE MONITORING OF THE ULTRAVIOLET SPECTRUM OF NGC 7469, I. Wanders, Bradley M. Peterson, D. Alloin, T.R. Ayres, J. Clavel, D. Michael Crenshaw, K. Horne, Gerard A. Kriss, Julian Henry Krolik, Matthew A. Malkan, Hagai Netzer, Paul T. O'Brien, G.A. Reichert, P.M. Rodriguez-Pascual, W. Wamsteker, T. Alexander, K. S.J. Anderson, E. Benitez, N.G. Bochkarev, A.N. Burenkov, F.-Z. Cheng, S.J. Collier, A. Comastri, M. Dietrich, D. Dultzin-Hacyan, B.R. Espey, A. V. Filippenko, C. Martin Gaskell, I.M. George, M.R. Goad, L.C. Ho, Shai Kaspi, W. Kollatschny, Kirk T. Korista, Ari Laor, G.M. MacAlpine, M. Mignoli, S.L. Morris, K. Nandra, S. Penton, Richard William Pogge, R.L. Ptak, J.M. Rodriguez-Espinoza, M. Santos-Lleo, A.I. Shapovalova, J.M. Shull, Stephanie A. Snedden, L.S. Sparke, G.M. Stirpe, W.-H. Sun, T.J. Turner, M.-H. Ulrich, T.-G. Wang, C. Wei, W.F. Welsh, S.-J. Xue, and Z.-L. Zhou

1996

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Evidence for Binary Orbital Motion of a Quasar Broad-Line Region, C. Martin Gaskell

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Supermassive Binaries and Extragalactic Jets, C. Martin Gaskell