Related papers: A Spectroscopic and Photometric Study of Short-Tim…

Profile variability of the H-alpha and H-beta broad emission lines in NGC5548

Between 1996 and 2002, we have carried out a spectral monitoring program for the Seyfert galaxy NGC 5548. High quality spectra (S/N>50), covering the spectral range (4000-7500)AA were obtained with the 6 m and 1 m telescopes of SAO (Russia)…

Astrophysics · Physics 2009-11-10 A. I. Shapovalova , V. T. Doroshenko , N. G. Bochkarev , A. N. Burenkov. L. Carrasco , V. H. Chavushyan , S. Collin , J. R. Valdes , N. Borisov , A-M. Dumont , V. V. Vlasuyk , I. Chillingarian , I. S. Fioktistova , O. M. Martinez

Steps Toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XVI. A Thirteen-Year Study of Spectral Variability in NGC 5548

We present the final installment of an intensive 13-year study of variations of the optical continuum and broad H-beta emission line in the Seyfert 1 galaxy NGC 5548. The data base consists of 1530 optical continuum measurements and 1248…

Astrophysics · Physics 2009-11-07 B. M. Peterson , the International AGN Watch

Space Telescope and Optical Reverberation Mapping Project. V. Optical Spectroscopic Campaign and Emission-Line Analysis for NGC 5548

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 cadence with…

Astrophysics of Galaxies · Physics 2017-03-22 L. Pei , M. M. Fausnaugh , A. J. Barth , B. M. Peterson , M. C. Bentz , G. De Rosa , K. D. Denney , M. R. Goad , C. S. Kochanek , K. T. Korista , G. A. Kriss , R. W. Pogge , V. N. Bennert , M. Brotherton , K. I. Clubb , E. Dalla Bontà , A. V. Filippenko , J. E. Greene , C. J. Grier , M. Vestergaard , W. Zheng , Scott M. Adams , Thomas G. Beatty , A. Bigley , Jacob E. Brown , Jonathan S. Brown , G. Canalizo , J. M. Comerford , Carl T. Coker , E. M. Corsini , S. Croft , K. V. Croxall , A. J. Deason , Michael Eracleous , O. D. Fox , E. L. Gates , C. B. Henderson , E. Holmbeck , T. W. -S. Holoien , J. J. Jensen , C. A. Johnson , P. L. Kelly , S. Kim , A. King , M. W. Lau , Miao Li , Cassandra Lochhaas , Zhiyuan Ma , E. R. Manne-Nicholas , J. C. Mauerhan , M. A. Malkan , R. McGurk , L. Morelli , Ana Mosquera , Dale Mudd , F. Muller Sanchez , M. L. Nguyen , P. Ochner , B. Ou-Yang , A. Pancoast , Matthew T. Penny , A. Pizzella , Radosław Poleski , Jessie Runnoe , B. Scott , Jaderson S. Schimoia , B. J. Shappee , I. Shivvers , Gregory V. Simonian , A. Siviero , Garrett Somers , Daniel J. Stevens , M. A. Strauss , Jamie Tayar , N. Tejos , T. Treu , J. Van Saders , L. Vican , S. Villanueva , H. Yuk , N. L. Zakamska , W. Zhu , M. D. Anderson , P. Arévalo , C. Bazhaw , S. Bisogni , G. A. Borman , M. C. Bottorff , W. N. Brandt , A. A. Breeveld , E. M. Cackett , M. T. Carini , D. M. Crenshaw , A. De Lorenzo-Cáceres , M. Dietrich , R. Edelson , N. V. Efimova , J. Ely , P. A. Evans , G. J. Ferland , K. Flatland , N. Gehrels , S. Geier , J. M. Gelbord , D. Grupe , A. Gupta , P. B. Hall , S. Hicks , D. Horenstein , Keith Horne , T. Hutchison , M. Im , M. D. Joner , J. Jones , J. Kaastra , S. Kaspi , B. C. Kelly , J. A. Kennea , M. Kim , S. C. Kim , S. A. Klimanov , J. C. Lee , D. C. Leonard , P. Lira , F. MacInnis , S. Mathur , I. M. McHardy , C. Montouri , R. Musso , S. V. Nazarov , H. Netzer , R. P. Norris , J. A. Nousek , D. N. Okhmat , I. Papadakis , J. R. Parks , J. -U. Pott , S. E. Rafter , H. -W. Rix , D. A. Saylor , K. Schnülle , S. G. Sergeev , M. Siegel , A. Skielboe , M. Spencer , D. Starkey , H. -I. Sung , K. G. Teems , C. S. Turner , P. Uttley , C. Villforth , Y. Weiss , J. -H. Woo , H. Yan , S. Young , Y. Zu

Long-term variability of the optical spectra of NGC 4151: I. Light curves and flux correlations

Results of a long-term spectral monitoring of the active galactic nucleus of NGC 4151 are presented (11 years, from 1996 to 2006). High quality spectra (S/N>50 in the continuum near Halpha and Hbeta) were obtained in the spectral range…

Astrophysics · Physics 2009-11-13 A. I. Shapovalova , L. C. Popovic , S. Collin , A. N. Burenkov , V. H. Chavushyan , N. G. Bochkarev , E. Benítez , D. Dultzin-Hacyan , A. Kovacevic , N. Borisov , L. Carrasco , J. Leon-Tavares , A. Mercado , J. R. Valdes , V. V. Vlasuyk , V. E. Zhdanova

Long-term optical spectral monitoring of NGC 7469

We present the results of the long-term (20-year period, from 1996 to 2015) optical spectral monitoring of the Seyfert 1 galaxy NGC 7469. The variation in the light-curves of the broad He II {\lambda}4686A H{\beta} and H{\alpha} lines, and…

Astrophysics of Galaxies · Physics 2017-01-09 Alla I. Shapovalova , L. C. Popović , V. H. Chavushyan , V. L. Afanasiev , D. Ilić , A. Kovacević , A. N. Burenkov , W. Kollatschny , O. Spiridonova , J. R. Valdes , N. G. Bochkarev , V. Patino-Alvarez , L. Carrasco , V. E. Zhdanova

Multiwavelength observations of short time-scale variability in NGC 4151. II. Optical observations

We present the results of an intensive ground-based spectrophotometric monitoring campaign of the Seyfert galaxy NGC~4151 for a period of over two months, with a typical temporal resolution of one day. Light curves for four optical…

Astrophysics · Physics 2009-10-28 S. Kaspi et al

Space Telescope and Optical Reverberation Mapping Project. IV. Anomalous behavior of the broad ultraviolet emission lines in NGC 5548

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 and broad…

Astrophysics of Galaxies · Physics 2016-06-15 M. R. Goad , K. T. Korista , G. De Rosa , G. A. Kriss , R. Edelson , A. J. Barth , G. J. Ferland , C. S. Kochanek , H. Netzer , B. M. Peterson , M. C. Bentz , S. Bisogni , D. M. Crenshaw , K. D. Denney , J. Ely , M. M. Fausnaugh , C. J. Grier , A. Gupta , K. D. Horne , J. Kaastra , A. Pancoast , L. Pei , R. W. Pogge , A. Skielboe , D. Starkey , M. Vestergaard , Y. Zu , M. D. Anderson , P. Arevalo , C. Bazhaw , G. A. Borman , T. A. Boroson , M. C. Bottorff , W. N. Brandt , A. A. Breeveld , B. J. Brewer , E. M. Cackett , M. T. Carini , K. V. Croxall , E. Dalla Bonta , A. de Lorenzo-Caceres , M. Dietrich , N. V. Efimova , P. A. Evans , A. V. Filippenko , K. Flatland , N. Gehrels , S. Geier , G. M. Gelbord , L. Gonzalez , V. Gorjian , D. Grupe , P. B. Hall , S. Hicks , D. Horenstein , T. Hutchison , M. Im , J. J. Jensen , M. D. Joner , J. Jones , S. Kaspi , B. C. Kelly , J. A. Kennea , M. Kim , S. C. Kim , S. A. Klimanov , V. M. Larionov , J. C. Lee , D. C. Leonard , P. Lira , F. MacInnis , E. R. Manne-Nicholas , S. Mathur , I. M. McHardy , C. Montouri , R. Musso , S. V. Nazarov , R. P. Norris , J. A. Nousek , D. N. Okhmat , I. Papadakis , J. R. Parks , J. -U. Pott , S. E. Rafter , H. -W. Rix , D. A. Saylor , J. S. Schimoia , K. Schnulle , S. G. Sergeev , M. Siegel , M. Spencer , H. -I. Sung , K. G. Teems , T. Treu , C. S. Turner , P. Uttley , C. Villforth , Y. Weiss , J. -H. Woo , H. Yan , S. Young , W. -K. Zheng

Anomalous behaviour of the UV-optical continuum bands in NGC 5548

During the 2014 HST/Swift and ground-based multi-wavelength monitoring campaign of NGC 5548 (AGN STORM), the UV-optical broad emission lines exhibited anomalous, decorrelated behaviour relative to the far-UV continuum flux variability.…

Astrophysics of Galaxies · Physics 2019-05-08 M. R. Goad , C. Knigge , K. T. Korista , E. Cackett , K. Horne , D. A. Starkey , B. M. Peterson , G. De Rosa , G. A. Kriss , R. Edelson , M. Fausnaugh

A novel approach to study the variability of NGC 5548

Understanding the properties of the continuum radiation and broad emission lines of active galactic nuclei provide significant information not only to model the radiation mechanism and constrain the geometry and kinematics of the broad-line…

Astrophysics of Galaxies · Physics 2019-07-17 A. Bewketu Belete , L. J. Goicoechea , I. C. Leao , B. L. Canto Martins , J. R. De Medeiros

Multiwavelength observations of short time-scale variability in NGC 4151. I. Ultraviolet observations

We present the results of an intensive ultraviolet monitoring campaign on the Seyfert 1 galaxy NGC 4151, as part of an effort to study its short time-scale variability over a broad range in wavelength. The nucleus of NGC 4151 was observed…

Astrophysics · Physics 2010-12-16 D. M. Crenshaw et al

Multi-wavelength variability analysis of the blazar S5 0716+714 during a long-lasting period of low activity

We conducted a multi-wavelength monitoring campaign of the blazar S5 0716+714 from 2022 November 26 to 2023 May 28 using optical telescopes in Egypt and Bulgaria. Data were taken during 84 nights in 11 of which intranight monitoring was…

High Energy Astrophysical Phenomena · Physics 2025-07-03 B. M. Mihov , E. G. Elhosseiny , L. S. Slavcheva-Mihova , A. Takey , M. N. Ismail , R. Mawad

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

Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994-95 are presented. The broad-band fluxes (B, V, R, and I), the spectrophotometric optical continuum flux F(5177) and the integrated emission-line fluxes of Ha, Hb, Hg,…

Astrophysics · Physics 2009-10-30 M. Dietrich , B. M. Peterson , P. Albrecht

Flare-like Variability of the Mg~II $\lambda$2798 \AA\ Emission Line and UV Fe~II band in the Blazar CTA~102

We report on the detection of a statistically significant flare-like event in the Mg~II~$\lambda$ 2798~\AA\ emission line and the UV~Fe~II band of CTA~102 during the outburst of autumn 2017. The ratio between the maximum and minimum of…

High Energy Astrophysical Phenomena · Physics 2020-03-11 Vahram Chavushyan , Víctor M. Patiño-Álvarez , Raúl A. Amaya-Almazán , Luis Carrasco

Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum

We model the ultraviolet spectra of the Seyfert 1 galaxy NGC~5548 obtained with the Hubble Space Telescope during the 6-month reverberation-mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption…

Astrophysics of Galaxies · Physics 2019-09-04 G. A. Kriss , G. De Rosa , J. Ely , B. M. Peterson , J. Kaastra , M. Mehdipour , G. J. Ferland , M. Dehghanian , S. Mathur , R. Edelson , K. T. Korista , N. Arav , A. J. Barth , M. C. Bentz , W. N. Brandt , D. M. Crenshaw , E. Dalla Bontà , K. D. Denney , C. Done , M. Eracleous , M. M. Fausnaugh , E. Gardner , M. R. Goad , C. J. Grier , Keith Horne , C. S. Kochanek , I. M. Mchardy , H. Netzer , A. Pancoast , L. Pei , R. W. Pogge , D. Proga , C. Silva , N. Tejos , M. Vestergaard , S. M. Adams , M. D. Anderson , P. Arévalo , T G. Beatty , E. Behar , V. N. Bennert , S. Bianchi , A. Bigley , S. Bisogni , R. Boissay-Malaquin , G. A. Borman , M. C. Bottorff , A. A. Breeveld , M. Brotherton , J. E. Brown , J. S. Brown , E. M. Cackett , G. Canalizo , M. Cappi , M. T. Carini , K. I. Clubb , J. M. Comerford , C. T. Coker , E. M. Corsini , E. Costantini , S. Croft , K. V. Croxall , A. J. Deason , A. De Lorenzo-Cáceres , B. De Marco , M. Dietrich , L. Di Gesu , J. Ebrero , P. A. Evans , A. V. Filippenko , K. Flatland , E. L. Gates , N. Gehrels , Z S. Geier , J. M. Gelbord , L. Gonzalez , V. Gorjian , D. Grupe , A. Gupta , P. B. Hall , C. B. Henderson , S. Hicks , E. Holmbeck , T. W. -S. Holoien , T. A. Hutchison , M. Im , J. J. Jensen , C. A. Johnson , M. D. Joner , S. Kaspi , B. C. Kelly , P. L. Kelly , J. A. Kennea , M. Kim , S. C. Kim , S. Y. Kim , A. King , S. A. Klimanov , Y. Krongold , M. W. Lau , J. C. Lee , D. C. Leonard , Miao Li , P. Lira , C. Lochhaas , Zhiyuan Ma , F. Macinnis , M. A. Malkan , E. R. Manne-Nicholas , G. Matt , J. C. Mauerhan , R. Mcgurk , C. Montuori , L. Morelli , A. Mosquera , D. Mudd , F. Müller-Sánchez , S. V. Nazarov , R. P. Norris , J. A. Nousek , M. L. Nguyen , P. Ochner , D. N. Okhmat , S. Paltani , J. R. Parks , C. Pinto , A. Pizzella , R. Poleski , G. Ponti , J. -U. Pott , S. E. Rafter , H. -W. Rix , J. Runnoe , D. A. Saylor , J. S. Schimoia , K. Schnülle , B. Scott , S. G. Sergeev , B. J. Shappee , I. Shivvers , M. Siegel , G. V. Simonian , A. Siviero , A. Skielboe , G. Somers , M. Spencer , D. Starkey , D. J. Stevens , H. -I. Sung , J. Tayar , K. G. Teems , T. Treu , C. S. Turner , P. Uttley , J . Van Saders , L. Vican , C. Villforth , S. Villanueva , D. J. Walton , T. Waters , Y. Weiss , J. -H. Woo , H. Yan , H. Yuk , W. Zheng , W. Zhu , Y. Zu

Combined Spectroscopic and Photometric Analysis of Flares in the Dwarf M Star EV Lacertae

We report results of an observing campaign to study the dwarf M flare star EV Lacertae. Between October 2021 and January 2022 we obtained concurrent B band photometry and low resolution spectroscopy of EV Lac on 39 occasions during 10 of…

Solar and Stellar Astrophysics · Physics 2023-07-28 David Boyd , Robert Buchheim , Sean Curry , Frank Parks , Keith Shank , Forrest Sims , Gary Walker , John Wetmore , James Jackman

Steps Toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. XV. Long-Term Optical Monitoring of NGC 5548

We present the results of three years of ground-based observations of the Seyfert 1 galaxy NGC 5548, which combined with previously reported data, yield optical continuum and broad-line H-beta light curves for a total of eight years. The…

Astrophysics · Physics 2009-10-30 B. M. Peterson , A. J. Barth , P. Berlind , R. Bertram , K. Bischoff , N. G. Bochkarev , A. N. Burenkov , F. -Z. Cheng , M. Dietrich , A. V. Filippenko , E. Giannuzzo , L. C. Ho , J. P. Huchra , J. Hunley , S. Kaspi , W. Kollatschny , D. C. Leonard , Yu. F. Malkov , T. Matheson , M. Mignoli , B. Nelson , P. Papaderos , J. Peters , R. W. Pogge , V. I. Pronik , S. G. Sergeev , E. A. Sergeeva , A. I. Shapovalova , G. M. Stirpe , S. Tokarz , R. M. Wagner , I. Wanders , J. -Y. Wei , B. J. Wilkes , H. Wu , S. -J. Xue , Z. -L. Zou

Long-Term X-ray Spectral Variability in Seyfert 1 Galaxies

Direct time-resolved spectral fitting has been performed on continuous RXTE monitoring of seven Seyfert 1 galaxies in order to study their broadband spectral variability and Fe K alpha variability characteristics on time scales of days to…

Astrophysics · Physics 2009-11-10 A. Markowitz , R. Edelson , S. Vaughan

Space Telescope and Optical Reverberation Mapping Project. III. Optical Continuum Emission and Broad-Band Time Delays in NGC 5548

We present ground-based optical photometric monitoring data for NGC 5548, part of an extended multi-wavelength reverberation mapping campaign. The light curves have nearly daily cadence from 2014 January to July in nine filters (\emph{BVRI}…

Astrophysics of Galaxies · Physics 2016-04-27 M. M. Fausnaugh , K. D. Denney , A. J. Barth , M. C. Bentz , M. C. Bottorff , M. T. Carini , K. V. Croxall , G. De Rosa , M. R. Goad , Keith Horne , M. D. Joner , S. Kaspi , M. Kim , S. A. Klimanov , C. S. Kochanek , D. C. Leonard , H. Netzer , B. M. Peterson , K. Schnulle , S. G. Sergeev , M. Vestergaard , W. -K. Zheng , Y. Zu , M. D. Anderson , P. Arevalo , C. Bazhaw , G. A. Borman , T. A. Boroson , W. N. Brandt , A. A. Breeveld , B. J. Brewer , E. M. Cackett , D. M. Crenshaw , E. Dalla Bonta , A. De Lorenzo-Caceres , M. Dietrich , R. Edelson , N. V. Efimova , J. Ely , P. A. Evans , A. V. Filippenko , K. Flatland , N. Gehrels , S. Geier , J. M. Gelbord , L. Gonzalez , V. Gorjian , C. J. Grier , D. Grupe , P. B. Hall , S. Hicks , D. Horenstein , T. Hutchison , M. Im , J. J. Jensen , J. Jones , J. Kaastra , B. C. Kelly , J. A. Kennea , S. C. Kim , K. T. Korista , G. A. Kriss , J. C. Lee , P. Lira , F. MacInnis , E. R. Manne-Nicholas , S. Mathur , I. M. McHardy , C. Montouri , R. Musso , S. V. Nazarov , R. P. Norris , J. A. Nousek , D. N. Okhmat , A. Pancoast , I. Papadakis , J. R. Parks , L. Pei , R. W. Pogge , J. -U. Pott , S. E. Rafter , H. -W. Rix , D. A. Saylor , J. S. Schimoia , M. Siegel , M. Spencer , D. Starkey , H. -I. Sung , K. G. Teems , T. Treu , C. S. Turner , P. Uttley , C. Villforth , Y. Weiss , J. -H. Woo , H. Yan , S. Young

Variability of Fe II Emission Features in the Seyfert 1 Galaxy NGC 5548

We study the low-contrast Fe II emission blends in the ultraviolet (1250--2200A) and optical (4000--6000A) spectra of the Seyfert 1 galaxy NGC 5548 and show that these features vary in flux and that these variations are correlated with…

Astrophysics · Physics 2009-11-10 M. Vestergaard , B. M. Peterson

Variability of NGC 4051 and the Nature of Narrow-Line Seyfert 1 Galaxies

We report on a three-year program of coordinated X-ray and optical monitoring of the Narrow-Line Seyfert 1 galaxy NGC 4051. The rapid continuum variations observed in the X-ray spectra are not detected in the optical, although the X-ray and…

Astrophysics · Physics 2009-10-31 B. M. Peterson , I. M. McHardy , B. J. Wilkes