Related papers: HUT Observations of Time-Variable Absorption in NG…

STIS Longslit Spectroscopy of the Narrow-Line Region of NGC 4151. II. Physical Conditions along Position Angle 221 Degress

We have examined the physical conditions in the narrow-line region of the well-studied Seyfert galaxy NGC 4151, using long-slit spectra obtained with the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). The data were…

Astrophysics · Physics 2009-10-31 S. B. Kraemer , D. M. Crenshaw , J. B. Hutchings , T. R. Gull , M. E. Kaiser , C. H. Nelson , D. Weistrop

Variable UV Absorption in the Seyfert 1.5 Galaxy NGC 3516: The Case for Associated UV and X-ray Absorption

We present observations of the UV absorption lines in the Seyfert 1 galaxy NGC 3516, obtained at a resolution of $\lambda$/$\Delta\lambda$ $\approx$ 40,000 with the Space Telescope Imaging Spectrograph (STIS) on 2000 October 1. The UV…

Astrophysics · Physics 2016-08-30 S. B. Kraemer , D. M. Crenshaw , I. M. George , H. Netzer , T. J. Turner , J. R. Gabel

Infrared spectroscopy of NGC4151: Probing the obscured ionizing AGN continuum

The ISO-SWS infrared spectroscopic observations of the nucleus of Seyfert galaxy NGC4151, which are described in a companion paper, are used together with a compilation of UV to IR narrow emission line data to determine the spectral shape…

Astrophysics · Physics 2009-10-30 Tal Alexander , Eckhard Sturm , Dieter Lutz , Amiel Sternberg , Hagai Netzer , Reinhard Genzel

The High Energy Spectrum of NGC 4151

We present the first INTEGRAL observations of the type 1.5 Seyfert galaxy NGC 4151. Combining several INTEGRAL observations performed during 2003, totaling about 400 ks of exposure time, allows us to study the spectrum in the 2 - 300 keV…

Astrophysics · Physics 2009-11-13 V. Beckmann , C. R. Shrader , N. Gehrels , S. Soldi , P. Lubinski , A. A. Zdziarski , P. -O. Petrucci , J. Malzac

Detection of Ongoing Mass Loss from HD 63433c, a Young Mini Neptune

We detect Lyman $\alpha$ absorption from the escaping atmosphere of HD 63433c, a $R=2.67 R_\oplus$, $P=20.5$ d mini Neptune orbiting a young (440 Myr) solar analogue in the Ursa Major Moving Group. Using HST/STIS, we measure a transit depth…

Earth and Planetary Astrophysics · Physics 2022-01-26 Michael Zhang , Heather A. Knutson , Lile Wang , Fei Dai , Leonardo A. dos Santos , Luca Fossati , Gregory W. Henry , David Ehrenreich , Yann Alibert , Sergio Hoyer , Thomas G. Wilson , Andrea Bonfanti

AGN STORM 2: VIII. Investigating the Narrow Absorption Lines in Mrk 817 Using HST-COS Observations

We observed the Seyfert 1 galaxy Mrk817 during an intensive multi-wavelength reverberation mapping campaign for 16 months. Here, we examine the behavior of narrow UV absorption lines seen in HST/COS spectra, both during the campaign and in…

Astrophysics of Galaxies · Physics 2024-07-09 Maryam Dehghanian , Nahum Arav , Gerard A. Kriss , Missagh Mehdipour , Doyee Byun , Gwen Walker , Mayank Sharma , Aaron J. Barth , Misty C. Bentz , Benjamin D. Boizelle , Michael S. Brotherton , Edward M. Cackett , Elena Dalla Bonta , Gisella De Rosa , Gary J. Ferland , Carina Fian , Alexei V. Filippenko , Jonathan Gelbord , Michael R. Goad , Keith Horne , Yasaman Homayouni , Dragana Ilic , Michael D. Joner , Erin A. Kara , Shai Kaspi , Christopher S. Kochanek , Kirk T. Korista , Peter Kosec , Andjelka B. Kovacevic , Hermine Landt , Collin Lewin , Ethan R. Partington , Luka C. Popovic , Daniel Proga , Daniele Rogantini , Matthew R. Siebert , Thaisa Storchi-Bergmann , Marianne Vestergaard , Timothy Waters , Jian-Min Wang , Fatima Zaidouni , Ying Zu

Multiwavelength campaign on Mrk 509. XVI. Continued HST/COS monitoring of the far-ultraviolet spectrum

To elucidate the location, physical conditions, mass outflow rate, and kinetic luminosity of the outflow from the active nucleus of the Seyfert 1 galaxy Mrk 509 we used coordinated ultraviolet and X-ray spectral observations in 2012 to…

Astrophysics of Galaxies · Physics 2019-03-13 G. A. Kriss , N. Arav , D. Edmonds , J. Ely , J. S. Kaastra , S. Bianchi , M. Cappi , E. Costantini , J. Ebrero , M. Mehdipour , S. Paltani , P. Petrucci , G. Ponti

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

Physical properties and the variability mechanism of the He I outflow in NGC 4151

We report on variable helium absorption lines in NGC 4151 observed across six epochs of quasi-simultaneous near-infrared and optical data. These observations cover the transitions from the metastable 2^3S state at 3889 A and 10830 A, and…

Astrophysics of Galaxies · Physics 2016-07-27 Conor Wildy , Hermine Landt , Michael R. Goad , Martin J. Ward , James S. Collinson

Multi-epoch UV $-$ X-ray spectral study of NGC 4151 with AstroSat

We present a multi-wavelength spectral study of NGC 4151 based on five epochs of simultaneous AstroSat observations in the near ultra-violet (NUV) to hard X-ray band ($\sim 0.005-80$ keV) during $2017 - 2018$. We derived the intrinsic…

High Energy Astrophysical Phenomena · Physics 2024-09-10 Shrabani Kumar , G. C. Dewangan , P. Gandhi , I. E. Papadakis , N. P. S. Mithun , K. P. Singh , D. Bhattacharya , A. A. Zdziarski , G. C. Stewart , S. Bhattacharyya , S. Chandra

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

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

Spatially Resolved Hopkins Ultraviolet Telescope Spectra of NGC 1068

We present spatially resolved far-UV spectra (912-1840 A) of NGC 1068 obtained using the Hopkins Ultraviolet Telescope (HUT) during the March 1995 Astro-2 mission. Three spectra of this prototypical Seyfert 2 galaxy were obtained through a…

Astrophysics · Physics 2009-10-31 John P. Grimes , Gerard A. Kriss , Brian R. Espey

Far Ultraviolet Spectroscopic Explorer Spectroscopy of Absorption and Emission Lines from the Narrow-Line Seyfert 1 Galaxy NGC 4051

We present three Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the Narrow-Line Seyfert 1 galaxy NGC4051. The most prominent features in the far-ultraviolet (FUV) spectrum are the OVI emission and absorption lines and the HI…

Astrophysics · Physics 2009-11-10 Shai Kaspi , W. N. Brandt , M. J. Collinge , Martin Elvis , Christopher S. Reynolds

The 0.9 Megasecond XRISM/Resolve Spectrum of the Seyfert-1 AGN NGC 4151

NGC 4151 is the brightest Seyfert-1 active galaxy in the pass band of the Resolve calorimeter spectrometer aboard XRISM. It has been observed on 14 occasions, resulting in a total exposure of 893 ks. Herein, we report on an analysis of the…

High Energy Astrophysical Phenomena · Physics 2026-04-20 Jon M. Miller , Xin Xiang , Missagh Mehdipour , Liyi Gu , Ehud Behar , Laura Brenneman , Doyee Byun , Elisa Costantini , Luigi Gallo , Javier A. Garcia , Matteo Guainazzi , Peter Kosec , Takeo Minezaki , Daiki Miura , Stephane Paltani , Abderahmen Zoghbi

Multiwavelength observations of short time-scale variability in NGC 4151. III. X-ray and Gamma-ray observations

A series of {\sl ROSAT\/}, {\sl ASCA\/} and Compton Gamma-Ray Observatory ({\sl CGRO\/}) observations of the Seyfert galaxy NGC 4151 were carried out during the period 1993 November 30 to December 13 as part of an intensive campaign to…

Astrophysics · Physics 2009-10-28 R. S. Warwick et al

Decoupling absorption and continuum variability in the Seyfert 2 NGC 4507

We present the results of the Suzaku observation of the Seyfert 2 galaxy NGC 4507. This source is one of the X-ray brightest Compton-thin Seyfert 2s and a candidate for a variable absorber. Suzaku caught NGC 4507 in a highly absorbed state…

High Energy Astrophysical Phenomena · Physics 2015-06-11 V. Braito , L. Ballo , J. N. Reeves , A. Ptak , G. Risaliti , T. J. Turner

Ubiquitous column density variability in Seyfert 2 Galaxies

We present a study of X-ray column density variability in Seyfert 2 galaxies. We show that variations in N_H are observed in almost all the objects with multiple hard X-ray observations. Variation timescales (as short as a few months in…

Astrophysics · Physics 2009-11-07 G. Risaliti , M. Elvis , F. Nicastro

The broad band spectrum and variability of NGC 4151 observed by BeppoSAX

We present an analysis of all SAX observations of NGC 4151. This source was observed 5 times from 1996 to 2001 with durations ranging from a day to four days. The intrinsic continuum, is absorbed at low energies by a complex system: a cold…

Astrophysics · Physics 2009-11-11 A. De Rosa , L. Piro , G. C. Perola , M. Capalbi , M. Cappi , P. Grandi , L. Maraschi , P. O. Petrucci

Subparsec-scale HI in the nucleus of NGC 4151

We present sensitive, high-resolution 21-cm VLBA+VLA observations of the radio jet and nuclear HI absorption in NGC 4151. The 25-mas (1.6-pc) resolution continuum image reveals a highly collimated radio jet, underlying the discrete…

Astrophysics · Physics 2007-05-23 C. G. Mundell , J. M. Wrobel , A. Pedlar , J. F. Gallimore