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The discrete correlation function: a new method for analysing unevenly sampled variability data
R. A. Edelson,J. H. Krolik +1 more
- Vol. 2, pp 387
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TLDR
It is shown that physical interpretation of active galactic nuclei cross-correlation functions requires knowledge of the input function's fluctuation power spectrum, involves model-dependence in the form of symmetry assumptions, and must take into account intrinsic scale bias.Abstract:
A method of measuring correlation functions without interpolating in the temporal domain, the discrete correlation function, is introduced. It provides an assumption-free representation of the correlation measured in the data, and allows meaningful error estimates. This method does not produce spurious correlations at zero lag due to correlated errors. It is shown that physical interpretation of active galactic nuclei cross-correlation functions requires knowledge of the input function's fluctuation power spectrum, involves model-dependence in the form of symmetry assumptions, and must take into account intrinsic scale bias. This technique was used to find a correlation in published IUE data for NGC 4151, which indicates that the broad C IV feature emanates from a shell 15 to 75 light-days in radius, assuming spherical symmetry.read more
Citations
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Reverberation Measurements for 17 Quasars and the Size-Mass-Luminosity Relations in Active Galactic Nuclei
TL;DR: In this article, the authors used spectro- photometrically monitored Palomar-Green quasars in order to obtain mea- surements of their emission lines and investigate the relationship between quasar luminosity, central black hole mass, and broad emission-line regions (BLRs) size in AGNs.
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The second catalog of active galactic nuclei detected by the Fermi Large Area Telescope
Markus Ackermann,Marco Ajello,Alice Allafort,Elisa Antolini,Elisa Antolini,W. B. Atwood,Magnus Axelsson,Magnus Axelsson,Luca Baldini,Jean Ballet,Guido Barbiellini,Guido Barbiellini,Denis Bastieri,Denis Bastieri,Keith Bechtol,Ronaldo Bellazzini,B. Berenji,Roger Blandford,E. D. Bloom,Emanuele Bonamente,Emanuele Bonamente,A. W. Borgland,Eugenio Bottacini,A. Bouvier,Johan Bregeon,M. Brigida,M. Brigida,P. Bruel,R. Buehler,T. H. Burnett,S. Buson,S. Buson,G. A. Caliandro,R. A. Cameron,P. A. Caraveo,J. M. Casandjian,E. Cavazzuti,C. Cecchi,C. Cecchi,Eric Charles,C. C. Cheung,C. C. Cheung,James Chiang,Stefano Ciprini,R. Claus,Johann Cohen-Tanugi,Jan Conrad,Jan Conrad,L. Costamante,S. Cutini,A. De Angelis,F. de Palma,F. de Palma,Charles D. Dermer,Seth Digel,E. Do Couto E Silva,Persis S. Drell,R. Dubois,L. Escande,C. Favuzzi,C. Favuzzi,Stephen Fegan,Elizabeth C. Ferrara,Justin D. Finke,W. B. Focke,P. Fortin,M. Frailis,Yasushi Fukazawa,Stefan Funk,P. Fusco,P. Fusco,F. Gargano,Dario Gasparrini,Neil Gehrels,S. Germani,S. Germani,B. Giebels,Nicola Giglietto,Nicola Giglietto,Paolo Giommi,F. Giordano,F. Giordano,Marcello Giroletti,T. Glanzman,G. Godfrey,I. A. Grenier,J. E. Grove,Sylvain Guiriec,Mats Gustafsson,Daniela Hadasch,M. Hayashida,M. Hayashida,E. Hays,S. E. Healey,D. Horan,Xian Hou,R. E. Hughes,G. Iafrate,Gudlaugur Johannesson,A. S. Johnson,W. N. Johnson,T. Kamae,Hideaki Katagiri,Jun Kataoka,Jürgen Knödlseder,Jürgen Knödlseder,M. Kuss,J. Lande,S. Larsson,Luca Latronico,Francesco Longo,Francesco Longo,F. Loparco,F. Loparco,Benoit Lott,M. N. Lovellette,P. Lubrano,P. Lubrano,G. M. Madejski,M. N. Mazziotta,W. McConville,W. McConville,Julie McEnery,Julie McEnery,Peter F. Michelson,W. Mitthumsiri,Tsunefumi Mizuno,A. A. Moiseev,A. A. Moiseev,C. Monte,C. Monte,M. E. Monzani,E. Moretti,E. Moretti,A. Morselli,Igor V. Moskalenko,S. Murgia,Takeshi Nakamori,M. Naumann-Godo,P. L. Nolan,Jay P. Norris,E. Nuss,M. Ohno,T. Ohsugi,Akira Okumura,Nicola Omodei,M. Orienti,E. Orlando,J. F. Ormes,M. Ozaki,David Paneque,David Paneque,D. Parent,D. Parent,Melissa Pesce-Rollins,M. Pierbattista,Silvia Piranomonte,F. Piron,G. Pivato,T. A. Porter,S. Rainò,S. Rainò,Riccardo Rando,Riccardo Rando,M. Razzano,M. Razzano,Soebur Razzaque,A. Reimer,Olaf Reimer,Steven Ritz,L. S. Rochester,Roger W. Romani,M. Roth,Daniel Sánchez,C. Sbarra,Jeffrey D. Scargle,T. L. Schalk,Carmelo Sgrò,M. S. Shaw,E. J. Siskind,Gloria Spandre,P. Spinelli,P. Spinelli,Andrew W. Strong,D. J. Suson,Hiroyasu Tajima,Hiroyasu Tajima,Hiromitsu Takahashi,Tadayuki Takahashi,Takaaki Tanaka,J. G. Thayer,J. B. Thayer,D. J. Thompson,L. Tibaldo,L. Tibaldo,M. Tinivella,Diego F. Torres,Diego F. Torres,Gino Tosti,Gino Tosti,Eleonora Troja,Yasunobu Uchiyama,Justin Vandenbroucke,V. Vasileiou,Giacomo Vianello,V. Vitale,V. Vitale,A. P. Waite,E. Wallace,P. Wang,Brian L Winer,D. L. Wood,D. L. Wood,K. S. Wood,Stephan Zimmer +214 more
TL;DR: The second catalog of active galactic nuclei (AGNs) detected by the Fermi Large Area Telescope (LAT) in two years of scientific operation is presented in this article, which includes 1017 γ-ray sources located at high Galactic latitudes (|b| > 10°) that are detected with a test statistic (TS) greater than 25 and associated statistically with AGNs.
Journal ArticleDOI
Variability of active galactic nuclei
TL;DR: In this article, the authors proposed the "accretion disk plus wind" model for radio-quiet active galactic nuclei (AGN) and blazars, which is the most appropriate model at present.
Journal ArticleDOI
Understanding the Lomb–Scargle Periodogram
TL;DR: The goal of this paper is to build intuition about what assumptions are implicit in the use of the Lomb-Scargle periodogram and related estimators of periodicity so as to motivate important practical considerations required in its proper application and interpretation.
Journal ArticleDOI
On Uncertainties in Cross‐Correlation Lags and the Reality of Wavelength‐dependent Continuum Lags in Active Galactic Nuclei
Bradley M. Peterson,Ignaz Wanders,Keith Horne,Stefan Collier,Tal Alexander,Shai Kaspi,Dan Maoz +6 more
TL;DR: In this paper, a model-independent method of assessing the uncertainties in cross-correlation lags determined from the light curves of active galactic nuclei (AGNs) was proposed.
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