Related papers: Short-term emission line and continuum variations …

Long-Term, Continuous Monitoring of the Broad Line Radio Galaxies 3C 390.3 and 3C 120 With the Rossi X-Ray Timing Explorer

We present a study of the flux and spectral variability of the two broad-line radio galaxies (BLRGs) 3C 390.3 and 3C 120, observed almost daily with RXTE for nearly two months each in 1996 and 1997, respectively. Our original motivation for…

Astrophysics · Physics 2009-11-07 M. Gliozzi , R. M. Sambruna , M. Eracleous

A systematic study of photoionized emission and warm absorption signatures of the NLS1 Mrk 335

We present an analysis of all the archival high resolution spectra of the Narrow-line Seyfert 1 galaxy Mrk~335 obtained with Reflection Grating Spectrometer (RGS) on board \textit{XMM-Newton}. The spectra show rich emission and absorption…

High Energy Astrophysical Phenomena · Physics 2021-08-24 H. Liu , M. L. Parker , J. Jiang , E. Kara , Cosimo Bambi , D. Grupe , S. Komossa

Variability in Optical Spectra of epsilon Orionis

We present the results of a time-series analysis of 130 echelle spectra of epsilon Ori (B0 Ia), acquired over seven observing seasons between 1998 and 2006 at Ritter Observatory. The equivalent widths of Halpha (net) and He I 5876 were…

Solar and Stellar Astrophysics · Physics 2013-03-05 Gregory B. Thompson , Nancy D. Morrison

An embedded circumnuclear disk in Mrk 273

Radio observations using very long baseline interferometry (VLBI) and the Westerbork interferometer have been carried out to study the hydroxyl Megamaser emission in Mrk~273 at different spatial resolutions. Line and continuum observations…

Astrophysics · Physics 2009-11-10 Hans-Rainer Kl"ockner , Willem A. Baan

Energy-dependent variability of the bare Seyfert 1 galaxy Ark 120

We present results from a detailed spectral-timing analysis of a long ~486 ks XMM-Newton observation of the bare Seyfert 1 galaxy Ark 120 which showed alternating diminution and increment in the 0.3-10 keV X-ray flux over four consecutive…

High Energy Astrophysical Phenomena · Physics 2017-09-13 Labani Mallick , Gulab C. Dewangan , I. M. McHardy , Mayukh Pahari

Broadband Multi-wavelength Properties of M87 during the 2018 EHT Campaign including a Very High Energy Flaring Episode

The nearby elliptical galaxy M87 contains one of the only two supermassive black holes whose emission surrounding the event horizon has been imaged by the Event Horizon Telescope (EHT). In 2018, more than two dozen multi-wavelength (MWL)…

High Energy Astrophysical Phenomena · Physics 2024-12-19 J. C. Algaba , M. Balokovic , S. Chandra , W. Y. Cheong , Y. Z. Cui , F. D'Ammando , A. D. Falcone , N. M. Ford , M. Giroletti , C. Goddi , M. A. Gurwell , K. Hada , D. Haggard , S. Jorstad , A. Kaur , T. Kawashima , S. Kerby , J. Y. Kim , M. Kino , E. V. Kravchenko , S. S. Lee , R. S. Lu , S. Markoff , J. Michail , J. Neilsen , M. A. Nowak , G. Principe , V. Ramakrishnan , B. Ripperda , M. Sasada , S. S. Savchenko , C. Sheridan , K. Akiyama , A. Alberdi , W. Alef , R. Anantua , K. Asada , R. Azulay , U. Bach , A. -K. Baczko , D. Ball , B. Bandyopadhyay , J. Barrett , M. Bauböck , B. A. Benson , D. Bintley , L. Blackburn , R. Blundell , K. L. Bouman , G. C. Bower , H. Boyce , M. Bremer , R. Brissenden , S. Britzen , A. E. Broderick , D. Broguiere , T. Bronzwaer , S. Bustamante , J. E. Carlstrom , A. Chael , C. -K. Chan , D. O. Chang , K. Chatterjee , S. Chatterjee , M. -T. Chen , Y. Chen , X. Cheng , I. Cho , P. Christian , N. S. Conroy , J. E. Conway , T. M. Crawford , G. B. Crew , A. Cruz-Osorio , R. Dahale , J. Davelaar , M. De Laurentis , R. Deane , J. Dempsey , G. Desvignes , J. Dexter , V. Dhruv , I. K. Dihingia , S. S. Doeleman , S. A. Dzib , R. P. Eatough , R. Emami , H. Falcke , J. Farah , V. L. Fish , E. Fomalont , H. A. Ford , M. Foschi , R. Fraga-Encinas , W. T. Freeman , P. Friberg , C. M. Fromm , A. Fuentes , P. Galison , C. F. Gammie , R. García , O. Gentaz , B. Georgiev , R. Gold , A. I. Gómez-Ruiz , J. L. Gómez , M. Gu , R. Hesper , D. Heumann , L. C. Ho , P. Ho , M. Honma , C. -W. L. Huang , L. Huang , D. H. Hughes , S. Ikeda , C. M. V. Impellizzeri , M. Inoue , S. Issaoun , D. J. James , B. T. Jannuzi , M. Janssen , B. Jeter , W. Jiang , A. Jiménez-Rosales , M. D. Johnson , A. C. Jones , A. V. Joshi , T. Jung , R. Karuppusamy , G. K. Keating , M. Kettenis , D. -J. Kim , J. Kim , J. Kim , J. Y. Koay , P. Kocherlakota , Y. Kofuji , P. M. Koch , S. Koyama , C. Kramer , J. A. Kramer , M. Kramer , T. P. Krichbaum , C. -Y. Kuo , N. La Bella , A. Levis , Z. Li , R. Lico , G. Lindahl , M. Lindqvist , M. Lisakov , J. Liu , K. Liu , E. Liuzzo , W. -P. Lo , A. P. Lobanov , L. Loinard , C. J. Lonsdale , A. E. Lowitz , N. R. MacDonald , J. Mao , N. Marchili , D. P. Marrone , A. P. Marscher , I. Martí-Vidal , S. Matsushita , L. D. Matthews , L. Medeiros , K. M. Menten , I. Mizuno , Y. Mizuno , J. Montgomery , J. M. Moran , K. Moriyama , M. Moscibrodzka , W. Mulaudzi , C. Müller , H. Müller , A. Mus , G. Musoke , I. Myserlis , H. Nagai , N. M. Nagar , D. G. Nair , M. Nakamura , G. Narayanan , I. Natarajan , A. Nathanail , S. Navarro Fuentes , C. Ni , J. Oh , H. Okino , H. Olivares , T. Oyama , F. Özel , D. C. M. Palumbo , G. Filippos Paraschos , J. Park , H. Parsons , N. Patel , U. -L. Pen , D. W. Pesce , V. Piétu , A. PopStefanija , O. Porth , B. Prather , D. Psaltis , H. -Y. Pu , R. Rao , M. G. Rawlings , A. W. Raymond , L. Rezzolla , A. Ricarte , F. Roelofs , C. Romero-Cañizales , E. Ros , A. Roshanineshat , H. Rottmann , A. L. Roy , I. Ruiz , C. Ruszczyk , K. L. J. Rygl , S. Sánchez , D. Sánchez-Argüelles , M. Sánchez-Portal , K. Satapathy , T. Savolainen , F. P. Schloerb , J. Schonfeld , K. -F. Schuster , L. Shao , Z. Shen , D. Small , B. W. Sohn , J. SooHoo , L. D. Sosapanta Salas , K. Souccar , J. S. Stanway , H. Sun , F. Tazaki , A. J. Tetarenko , P. Tiede , R. P. J. Tilanus , M. Titus , K. Toma , P. Torne , T. Toscano , E. Traianou , T. Trent , S. Trippe , M. Turk , I. van Bemmel , H. J. van Langevelde , D. R. van Rossum , J. Vos , J. Wagner , D. Ward-Thompson , J. Wardle , J. E. Washington , J. Weintroub , R. Wharton , M. Wielgus , K. Wiik , G. Witzel , M. F. Wondrak , G. N. Wong , Q. Wu , N. Yadlapalli , P. Yamaguchi , A. Yfantis , D. Yoon , A. Young , Z. Younsi , W. Yu , F. Yuan , Y. -F. Yuan , J. A. Zensus , S. Zhang , G. -Y. Zhao , S. -S. Zhao , R. Bellazzini , B. Berenji , E. Bissaldi , R. D. Blandford , R. Bonino , P. Bruel , R. A. Cameron , P. A. Caraveo , E. Cavazzuti , C. C. Cheung , S. Ciprini , P. Cristarella Orestano , S. Cutini , N. Di Lalla , A. Dinesh , L. Di Venere , A. Domínguez , S. J. Fegan , A. Franckowiak , Y. Fukazawa , P. Fusco , F. Gargano , C. Gasbarra , S. Germani , M. Giliberti , I. A. Grenier , E. Hays , D. Horan , M. Kuss , S. Larsson , I. Liodakis , F. Longo , F. Loparco , M. N. Lovellette , S. Maldera , M. N. Mazziotta , I. Mereu , P. F. Michelson , N. Mirabal , T. Mizuno , M. E. Monzani , A. Morselli , M. Negro , N. Omodei , E. Orlando , M. Persic , S. Rainò , B. Rani , A. Reimer , O. Reimer , M. Sánchez-Conde , P. M. Saz Parkinson , C. Sgrò , E. J. Siskind , P. Spinelli , D. J. Suson , H. Tajima , D. F. Torres , G. Zaharijas , F. Aharonian , F. Ait Benkhali , J. Aschersleben , H. Ashkar , M. Backes , V. Barbosa Martins , R. Batzofin , Y. Becherini , D. Berge , M. Böttcher , C. Boisson , J. Bolmont , M. de Bony de Lavergne , J. Borowska , M. Bouyahiaoui , F. Bradascio , R. Brose , A. Brown , B. Bruno , T. Bulik , C. Burger-Scheidlin , S. Casanova , R. Cecil , J. Celic , M. Cerruti , T. Chand , A. Chen , J. Chibueze , O. Chibueze , T. Czerny , M. Dainotti , F. Dubus , J. Dumm , G. D'Urso , A. Drouhin , P. Durouchoux , D. Fabbian , D. Franczak , M. Funk , J. Gabanyi , G. Gaggero , N. Garcia , A. Geiger , M. G. Giorgi , S. Gleeson , S. Gonzalez , G. T. Gauthier , P. Grasso , T. Hovatta , J. Hyman , C. Kaaret , D. Kirk , S. Lal , T. M. Lesch , K. Lohmann , C. Massaro , M. Mayer , P. J. Meintjes , E. Miral , A. Mirra , J. Neronov , E. Padovani , F. Paccagnella , E. Parisi , A. Piotrowska , S. Pohl , G. Puga , L. R. Ramirez , S. Reville , D. S. Rowell , M. Rudge , G. Rybka , M. S. Schlenstedt , E. S. Seo , J. Svirski , J. R. Taylor , F. Torres , K. Tsujimoto , F. Tosti , S. Volpi , N. A. Walraven , L. Welker , M. Zietkiewicz , G. Abdalla , C. Aleva , H. A. Ait Benkhali , M. Aldous , M. Amin , M. A. Aschieri , E. de Deus , J. de Los Santos , D. Fontanot , S. Jorfi , P. Levens , A. E. E. Zwart , S. Oliviero , D. Puglisi , M. Thiel , C. Zaharijas , F. Amaral , L. Boella , L. Holincheck , R. Queiroz , H. Sofue , G. Tellis , G. Wagner , A. Wierzcholska , M. Zacharias , A. A. Zdziarski , A. Zech , N. Zywucka , S. Abe , J. Abhir , A. Abhishek , V. A. Acciari , A. Aguasca-Cabot , I. Agudo , T. Aniello , S. Ansoldi , L. A. Antonelli , A. Arbet Engels , C. Arcaro , M. Artero , K. Asano , A. Babic , U. Barres de Almeida , J. A. Barrio , I. Batkovic , A. Bautista , J. Baxter , J. Becerra González , W. Bednarek , E. Bernardini , J. Bernete , A. Berti , J. Besenrieder , C. Bigongiari , A. Biland , O. Blanch , G. Bonnoli , Z. Bosnjak , E. Bronzini , I. Burelli , G. Busetto , A. Campoy-Ordaz , A. Carosi , R. Carosi , M. Carretero-Castrillo , A. J. Castro-Tirado , D. Cerasole , G. Ceribella , Y. Chai , A. Cifuentes , E. Colombo , J. L. Contreras , J. Cortina , S. Covino , G. D'Amico , V. D'Elia , P. Da Vela , F. Dazzi , A. De Angelis , B. De Lotto , R. de Menezes , M. Delfino , J. Delgado , C. Delgado Mendez , F. Di Pierro , R. Di Tria , L. Di Venere , D. Dominis Prester , A. Donini , D. Dorner , M. Doro , D. Elsaesser , J. Escudero , L. Fariña , A. Fattorini , L. Foffano , L. Font , S. Fröse , S. Fukami , Y. Fukazawa , R. J. García López , M. Garczarczyk , S. Gasparyan , M. Gaug , J. G. Giesbrecht Paiva , N. Giglietto , F. Giordano , P. Gliwny , N. Godinovic , T. Gradetzke , R. Grau , D. Green , J. G. Green , P. Günther , D. Hadasch , A. Hahn , T. Hassan , L. Heckmann , J. Herrera Llorente , D. Hrupec , R. Imazawa , K. Ishio , I. Jiménez Martínez , J. Jormanainen , T. Kayanoki , D. Kerszberg , G. W. Kluge , Y. Kobayashi , P. M. Kouch , H. Kubo , J. Kushida , M. Laínez , A. Lamastra , F. Leone , E. Lindfors , S. Lombardi , R. López-Coto , M. López-Moya , A. López-Oramas , S. Loporchio , A. Lorini , E. Lyard , B. Machado de Oliveira Fraga , P. Majumdar , M. Makariev , G. Maneva , M. Manganaro , S. Mangano , K. Mannheim , M. Mariotti , M. Martínez , M. Martínez-Chicharro , A. Mas-Aguilar , D. Mazin , S. Menchiari , S. Mender , D. Miceli , T. Miener , J. M. Miranda , R. Mirzoyan , M. Molero González , E. Molina , H. A. Mondal , A. Moralejo , D. Morcuende , T. Nakamori , C. Nanci , V. Neustroev , L. Nickel , M. Nievas Rosillo , C. Nigro , L. Nikolic , K. Nilsson , K. Nishijima , T. Njoh Ekoume , K. Noda , S. Nozaki , Y. Ohtani , A. Okumura , J. Otero-Santos , S. Paiano , D. Paneque , R. Paoletti , J. M. Paredes , M. Peresano , M. Persic , M. Pihet , G. Pirola , F. Podobnik , P. G. Prada Moroni , E. Prandini , C. Priyadarshi , M. Ribó , J. Rico , C. Righi , N. Sahakyan , T. Saito , F. G. Saturni , K. Schmidt , F. Schmuckermaier , J. L. Schubert , T. Schweizer , A. Sciaccaluga , G. Silvestri , J. Sitarek , V. Sliusar , D. Sobczynska , A. Spolon , A. Stamerra , J. Strišković , D. Strom , M. Strzys , Y. Suda , S. Suutarinen , H. Tajima , M. Takahashi , R. Takeishi , F. Tavecchio , P. Temnikov , K. Terauchi , T. Terzic , M. Teshima , S. Truzzi , A. Tutone , S. Ubach , J. van Scherpenberg , M. Vazquez Acosta , S. Ventura , G. Verna , I. Viale , C. F. Vigorito , V. Vitale , I. Vovk , R. Walter , M. Will , C. Wunderlich , T. Yamamoto , A. Acharyya , C. B. Adams , P. Bangale , J. T. Bartkoske , W. Benbow , J. L. Christiansen , A. Duerr , M. Errando , Q. Feng , G. M. Foote , L. Fortson , A. Furniss , W. Hanlon , O. Hervet , C. E. Hinrichs , J. Holder , T. B. Humensky , W. Jin , M. N. Johnson , P. Kaaret , M. Kertzman , D. Kieda , T. K. Kleiner , N. Korzoun , F. Krennrich , S. Kumar , M. J. Lang , M. Lundy , G. Maier , C. E. McGrath , M. J. Millard , C. L. Mooney , P. Moriarty , R. Mukherjee , W. Ning , S. O'Brien , R. A. Ong , M. Pohl , E. Pueschel , J. Quinn , K. Ragan , P. T. Reynolds , D. Ribeiro , E. Roache , J. L. Ryan , I. Sadeh , L. Saha , M. Santander , G. H. Sembroski , R. Shang , M. Splettstoesser , A. K. Talluri , J. V. Tucci , J. Valverde , V. V. Vassiliev , D. A. Williams , S. L. Wong , Z. Chen , L. Cui , T. Hirota , B. Li , G. Li , Q. Liu , X. Liu , Z. Liu , J. Ma , K. Niinuma , H. Ro , N. Sakai , S. Sawada-Satoh , K. Wajima , J. Wang , N. Wang , B. Xia , H. Yan , Y. Yonekura , H. Zhang , R. Zhao , W. Zhong , The Event Horizon Telescope - Multi-wavelength science working group , The Event Horizon Telescope Collaboration , The Fermi Large Area Telescope Collaboration , H. E. S. S. Collaboration , MAGIC Collaboration , VERITAS Collaboration , EAVN Collaboration

XMM-Newton long-look observation of the narrow line Seyfert 1 galaxy PKS0558-504; I: Spectral analysis

We present results from the spectral analysis of a long XMM-Newton observation of the radio-loud NLS1 galaxy PKS0558-504. The source is highly variable, on all sampled time scales. We did not observe any absorption features in either the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 I. E. Papadakis , W. Brinkmann , M. Gliozzi , C. Raeth , F. Nicastro , M. L. Conciatore

A Relativistic Jet in the Radio Quiet AGN Mrk 110

We report the discovery of a relativistic jet in Mrk~110, a narrow-line Seyfert 1 galaxy historically classified as a radio-quiet active galactic nucleus (AGN). Very Long Baseline Interferometry (VLBI) observations reveal intermittent jet…

Astrophysics of Galaxies · Physics 2025-06-05 Ailing Wang , Tao An , Kenneth I. Kellermann , Hua Feng , Emmanuel K. Bempong-Manful , Roland Timmerman , Shaoguang Guo

The long-term broad-line responsivity in MKN 110

We examine the long-term history of the optical spectrum of the extremely variable Active Galactic Nucleus (AGN) MKN 110. By combining various archival data with new data, we cover an unprecedented long period of $\sim$30 years (1987 -…

Astrophysics of Galaxies · Physics 2022-12-14 D. Homan , A. Lawrence , M. Ward , A. Bruce , H. Landt , C. MacLeod , M. Elvis , B. Wilkes , J. P. Huchra , B. M. Peterson

Highly ionized Fe K emission lines from the LINER galaxy M 81

We present spectral and timing results from a long (130 ks) XMM-NEWTON EPIC observation of the nucleus of the Seyfert/LINER galaxy M 81. During the observation the X-ray flux varied by 20%, but there was no significant change in spectral…

Astrophysics · Physics 2009-11-10 M. J. Page , R. Soria , S. Zane , K. Wu , R. Starling

Evidence for Two Distinct Broad-Line Regions from Reverberation Mapping of PG 0026+129

We report on the results of a new spectroscopic monitoring campaign of the quasar PG 0026+129 at the Calar Alto Observatory 2.2m telescope from July 2017 to February 2020. Significant variations in the fluxes of the continuum and…

Astrophysics of Galaxies · Physics 2020-12-23 Chen Hu , Sha-Sha Li , Wei-Jian Guo , Sen Yang , Zi-Xu Yang , Dong-Wei Bao , Bo-Wei Jiang , Pu Du , Yan-Rong Li , Ming Xiao , Yu-Yang Songsheng , Zhe Yu , Jin-Ming Bai , Luis C. Ho , Wei-Hao Bian , Michael S. Brotherton , Ye-Fei Yuan , Jesús Aceituno , Hartmut Winkler , Jian-Min Wang

UV flux variation study in contact binary VW Cephei

Despite many attempts, the origin of UV emission line and continuum in contact binary stars remains unclear. We present a substantial UV spectroscopic analysis of VW Cephei, a late-type contact binary system, using 46 low-resolution spectra…

Solar and Stellar Astrophysics · Physics 2025-08-04 Anurag Baruah , Mayukh Pahari

Fe K emission and absorption features in XMM-Newton spectra of Mkn 766 - evidence for reprocessing in flare ejecta

We report on the analysis of a long XMM-Newton EPIC observation in 2001 May of the Narrow Line Seyfert 1 galaxy Mkn 766. The 3-11 keV spectrum exhibits a moderately steep power law continuum, with a broad emission line at ~6.7 keV, probably…

Astrophysics · Physics 2009-11-07 K. A. Pounds , J. N. Reeves , K. L. Page , G. A. Wynn , P. T. O'Brien

Rapid Infrared Variability of Three Radio-loud Narrow-line Seyfert 1 Galaxies: A View from the Wide-field Infrared Survey Explorer

Using newly released data from the Wide-field Infrared Survey Explorer, we report the discovery of rapid infrared variability in three radio-loud narrow-line Seyfert 1 galaxies (NLS1s) selected from the 23 sources in the sample of Yuan et…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Ning Jiang , Hong-Yan Zhou , Luis C. Ho , Weimin Yuan , Ting-Gui Wang , Xiao-Bo Dong , Peng Jiang , Tuo Ji , Qiguo Tian

Time-delay measurement of MgII broad line response for the highly-accreting quasar HE 0413-4031: Implications for the MgII-based radius-luminosity relation

We present the monitoring of the AGN continuum and MgII broad line emission for the quasar HE 0413-4031 ($z=1.38$) based on the six-year monitoring by the South African Large Telescope (SALT). We managed to estimate a time-delay of…

Astrophysics of Galaxies · Physics 2020-07-01 Michal Zajaček , Bożena Czerny , Mary Loli Martinez-Aldama , Mateusz Rałowski , Aleksandra Olejak , Swayamtrupta Panda , Krzysztof Hryniewicz , Marzena Śniegowska , Mohammad-Hassan Naddaf , Wojtek Pych , Grzegorz Pietrzyński , C. Sobrino Figaredo , Martin Haas , Justyna Średzińska , Magdalena Krupa , Agnieszka Kurcz , Andrzej Udalski , Marek Gorski , Marek Sarna

Revealing the Nature and Location of High Energy Emission in the Candidate Binary SMBH System OJ 287

The latest flare of the regular $\sim$ 12 years quasi-periodic optical outbursts in the binary SMBH candidate system OJ 287 occurred in December 2015. Following this, the source has exhibited enhanced multi-wavelength (MW) variability in…

High Energy Astrophysical Phenomena · Physics 2023-06-07 Pankaj Kushwaha , E. M. de Gouveia Dal Pino , Alok C. Gupta , Paul J. Wiita

Broad line region and black hole mass of PKS 1510-089 from spectroscopic reverberation mapping

Reverberation results of a flat spectrum radio quasar PKS 1510-089 are presented from 8.5-years long spectroscopic monitoring carried out in 9 observing seasons between December 2008 to June 2017 at Steward Observatory. Optical spectra show…

Astrophysics of Galaxies · Physics 2020-10-07 Suvendu Rakshit

Long-term variability of the optical spectra of NGC 4151: II. Evolution of the broad Ha and Hb emission-line profiles

Results of the long-term (11 years, from 1996 to 2006) H$\alpha$ and H$\beta$ line variations of the active galactic nucleus of NGC 4151 are presented. High quality spectra (S/N>50 and R~8A) of H$\alpha$ and H$\beta$ were investigated. We…

Astrophysics of Galaxies · Physics 2015-05-14 A. I. Shapovalova , L. C. Popovic , A. N. Burenkov , V. H. Chavushyan , D. Ilic , A. Kovacevic , N. G. Bochkarev , J. Leon-Tavares

Rapidly variable Fe K$\alpha$ line in NGC 4051

We present a detailed analysis on the variability of the Fe K emission line in NGC 4051 using ASCA data. Through simple Gaussian line fits, we find not only obvious Fe K line variability with no significant difference in the X-ray continuum…

Astrophysics · Physics 2009-10-31 J. X. Wang , Y. Y. Zhou , H. G. Xu , T. G. Wang

Multi-wavelength Observations of VHE BL Lac Objects

We present multi-wavelength observations of the very high energy (VHE, E >250 GeV) gamma-ray sources Mrk 421 and Mrk 501. The VHE data presented here were taken with the Whipple Observatory 10m gamma-ray telescope. In the Mrk 421 campaign,…

Astrophysics · Physics 2019-08-14 M. Catanese