Related papers: Long-Term X-ray Spectral Variability in Seyfert 1 …

The broad band spectral variability of MCG-6-30-15 observed by NuSTAR and XMM-Newton

MCG-6-30-15, at a distance of 37 Mpc (z=0.008), is the archetypical Seyfert 1 galaxy showing very broad Fe K$\alpha$ emission. We present results from a joint NuSTAR and XMM-Newton observational campaign that, for the first time, allows a…

High Energy Astrophysical Phenomena · Physics 2015-06-19 A. Marinucci , G. Matt , G. Miniutti , M. Guainazzi , M. L. Parker , L. Brenneman , A. C. Fabian , E. Kara , P. Arevalo , D. R. Ballantyne , S. E. Boggs , M. Cappi , F. E. Christensen , W. W. Craig , M. Elvis , C. J. Hailey , F. A. Harrison , C. S. Reynolds , G. Risaliti , D. K. Stern , D. J. Walton , W. Zhang

Multiwavelength observations of short time-scale variability in NGC 4151. IV. Analysis of multiwavelength continuum variability

This paper combines data from the three preceding papers in order to analyze the multi-waveband variability and spectral energy distribution of the Seyfert~1 galaxy NGC~4151 during the December 1993 monitoring campaign. The source, which…

Astrophysics · Physics 2009-10-28 R. A. Edelson et al

X-ray and optical variability of Seyfert 1 galaxies as observed with XMM-Newton

We have examined simultaneous X-ray and optical light curves of a sample of eight nearby Seyfert 1 galaxies observed using the EPIC X-ray cameras and Optical Monitor on board XMM. The observations span ~1 day and revealed optical…

Astrophysics · Physics 2008-11-26 R. Smith , S. Vaughan

X-ray narrow line region variability as a geometry probe: The case of NGC 5548

We study the long time scale variability of the gas responsible for the X-ray narrow emission lines in the Seyfert 1 galaxy NGC 5548, in order to constrain the location and geometry of the emitting gas. Using X-ray spectra taken with the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 R. G. Detmers , J. S. Kaastra , I. M. McHardy

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

A Possible 100-day X-ray-to-Optical Lag in the Variations of the Seyfert 1 Nucleus NGC 3516

We present optical broadband (B and R) observations of the Seyfert 1 nucleus NGC 3516, obtained at Wise Observatory from 1997 March to 1998 September, contemporaneously with the X-ray 2-10 keV measurements of RXTE. The cross correlation…

Astrophysics · Physics 2009-10-31 Dan Maoz , Rick Edelson , Kirpal Nandra

Simple interpretation of the seemingly complicated X-ray spectral variation of NGC 5548

NGC 5548 is a very well-studied Seyfert 1 galaxy in broad wavelengths. Previous multiwavelength observation campaigns have indicated that its multiple absorbers are highly variable and complex. A previous study applied a two-zone partial…

High Energy Astrophysical Phenomena · Physics 2022-05-09 Takuya Midooka , Ken Ebisawa , Misaki Mizumoto , Yasuharu Sugawara

X-ray spectroscopy and time variability of Narrow Line Seyfert 1

We present the main results of broad band (0.1-10 keV) BeppoSAX observations of a selected sample of Narrow Line Seyfert 1 galaxies (NLS1s). We have performed a spectroscopic analysis of LECS and MECS data to test their average spectral…

Astrophysics · Physics 2007-05-23 F. Cancelliere , A. Comastri

Origin of the Broad Iron Line Feature and the Soft X-ray Variation in Seyfert Galaxies

Many Seyfert galaxies are known to exhibit significant X-ray spectral variations and seemingly broad iron K-emission line features. In this paper, we show that the "variable partial covering model", which has been successfully proposed for…

High Energy Astrophysical Phenomena · Physics 2016-03-23 Naoki Iso , Ken Ebisawa , Hiroaki Sameshima , Misaki Mizumoto , Takehiro Miyakawa , Hajime Inoue , Hiroki Yamasaki

Exploring the spectral variability of the Seyfert 1.5 galaxy Markarian 530 with Suzaku

A 2012 Suzaku observation of the Seyfert 1.5 galaxy Markarian 530 was analysed and found to exhibit two distinct modes of variability, which were found to be independent from one another. Firstly, the spectrum undergoes a smooth transition…

High Energy Astrophysical Phenomena · Physics 2018-06-06 H. J. S. Ehler , A. G. Gonzalez , L. C. Gallo

Multiwavelength Monitoring of the Narrow-Line Seyfert 1 Galaxy Akn 564. II. Ultraviolet Continuum and Emission-line Variability

We present results of an intensive two-month campaign of approximately daily spectrophotometric monitoring of the narrow-line Seyfert 1 galaxy Akn 564 with HST. The fractional variability amplitude of the continuum variations between…

Astrophysics · Physics 2009-11-06 S. Collier , D. M. Crenshaw , B. M. Peterson , W. N. Brandt , J. Clavel , R. Edelson , I. M. George , K. Horne , G. A. Kriss , S. Mathur , H. Netzer , P. T. O'Brien , R. W. Pogge , K. A. Pounds , P. Romano , O. Shemmer , T. J. Turner , W. Wamsteker

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

We describe the first results from a six-month long reverberation-mapping experiment in the ultraviolet based on 170 observations of the Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on the Hubble Space Telescope.…

Astrophysics of Galaxies · Physics 2015-07-10 G. De Rosa , B. M. Peterson , J. Ely , G. A. Kriss , D. M. Crenshaw , Keith Horne , K. T. Korista , H. Netzer , R. W. Pogge , P. Arevalo , A. J. Barth , M. C. Bentz , W. N. Brandt , A. A. Breeveld , B. J. Brewer , E. Dalla Bonta , A. De Lorenzo-Caceres , K. D. Denney , M. Dietrich , R. Edelson , P. A. Evans , M. M. Fausnaugh , N. Gehrels , J. M. Gelbord , M. R. Goad , C. J. Grier , D. Grupe , P. B. Hall , J. Kaastra , B. C. Kelly , J. A. Kennea , C. S. Kochanek , P. Lira , S. Mathur , I. M. McHardy , J. A. Nousek , A. Pancoast , I. Papadakis , L. Pei , J. S. Schimoia , M. Siegel , D. Starkey , T. Treu , P. Uttley , S. Vaughan , M. Vestergaard , C. Villforth , H. Yan , S. Young , Y. Zu

X-ray flux variability of active galactic nuclei observed using NuSTAR

We present results on a systematic study of flux variability on hourly time-scales in a large sample of active galactic nuclei (AGN) in the 3-79 keV band using data from Nuclear Spectroscopic Telescope Array. Our sample consists of 4 BL Lac…

Astrophysics of Galaxies · Physics 2017-02-01 Priyanka Rani , C. S. Stalin , Suvendu Rakshit

Long-term optical spectral monitoring of a changing-look AGN NGC 3516 I: Continuum and broad-line flux variability

Here we present the long-term optical spectral monitoring of a changing-look active galactic nuclei (AGN) NGC 3516 that covers 22 years (from 1996 to 2018). We explore a variability in the broad lines and continuum, finding that the…

Astrophysics of Galaxies · Physics 2019-04-10 A. I. Shapovalova , L. C. Popovic , V. L. Afanasiev , D. Ilic , A. Kovacevic , A. N. Burenkov , V. H. Chavushyan , S. Marceta-Mandic , O. Spiridonova , J. R. Valdes , N. G. Bochkarev , V. Patino-Alvarez , L. Carrasco , V. E. Zhdanova

Evidence for periodicity in 43 year-long monitoring of NGC 5548

We present an analysis of 43 years (1972 to 2015) of spectroscopic observations of the Seyfert 1 galaxy NGC 5548. This includes 12 years of new unpublished observations (2003 to 2015). We compiled about 1600 H$\beta$ spectra and analyzed…

High Energy Astrophysical Phenomena · Physics 2016-09-22 E. Bon , S. Zucker , H. Netzer , P. Marziani , N. Bon , P. Jovanović , A. I. Shapovalova , S. Komossa , C. M. Gaskell , L. Č. Popović , S. Britzen , V. H. Chavushyan , A. N. Burenkov , S. Sergeev , G. La Mura , J. R. Valdés , M. Stalevski

Correlation and time delays of the X-ray and optical emission of the Seyfert Galaxy NGC3783

We present simultaneous X-ray and optical B and V band light curves of the Seyfert Galaxy NGC3783 spanning 2 years. The flux in all bands is highly variable and the fluctuations are significantly correlated. As shown before by Stirpe et al.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 P. Arevalo , P. Uttley , P. Lira , E. Breedt , I. M. McHardy , E. Churazov

X-ray spectral variability of seven LINER nuclei with XMM-Newton and Chandra data

One of the most important features in active galactic nuclei (AGN) is the variability of their emission. Variability has been discovered at X-ray, UV, and radio frequencies on time scales from hours to years. Among the AGN family and…

High Energy Astrophysical Phenomena · Physics 2015-06-15 L. Hernández-García , O. González-Martín , I. Márquez , J. Masegosa

A longer XMM-Newton look at I Zwicky 1: Variability of the X-ray continuum, absorption, and iron Kalpha line

We present the second XMM-Newton observation (85 ks) of the narrow-line Seyfert 1 galaxy (NLS1) I Zw 1 and describe its mean spectral and timing characteristics. On average, I Zw 1 is ~35 per cent dimmer in 2005 than in the shorter (20 ks)…

Astrophysics · Physics 2008-11-26 L. C. Gallo , W. N. Brandt , E. Costantini , A. C. Fabian , K. Iwasawa , I. E. Papadakis

Fourier Resolved Spectroscopy of the XMM-Newton Observations of MCG -6-30-15

We study the Frequency Resolved Spectra of the Seyfert galaxy MCG -6-30-15 obtained during two recent XMM-Newton observations. Splitting the Fourier spectra in soft (<2 keV) and hard (>2 keV) bands, we find that the soft band has a…

Astrophysics · Physics 2009-11-11 I. E. Papadakis , D. Kazanas , A. Akylas

Apparent \oiii variability in the narrow line Seyfert I Mrk142

In this letter, we checked spectral properties of the well-known narrow line Seyfert I Mrk142, in order to try to find effects of narrow line variability on BLR radius of Mrk142 which is an outlier in the R-L plane. Although, no improvement…

Astrophysics of Galaxies · Physics 2016-01-20 XueGuang Zhang , LongLong Feng