The Low-luminosity End of the Radius-Luminosity Relationship for Active Galactic Nuclei
Misty C. Bentz,Kelly D. Denney,Catherine J. Grier,Aaron J. Barth,Bradley M. Peterson,Marianne Vestergaard,Marianne Vestergaard,Vardha N. Bennert,Gabriela Canalizo,Gisella De Rosa,Alexei V. Filippenko,Elinor L. Gates,Jenny E. Greene,Weidong Li,Matthew A. Malkan,Richard W. Pogge,Daniel Stern,Tommaso Treu,Jong-Hak Woo +18 more
TLDR
In this article, the authors present an updated and revised analysis of the relationship between the H{beta} broadline region (BLR) radius and the luminosity of the active galactic nucleus (AGN).Abstract:
We present an updated and revised analysis of the relationship between the H{beta} broad-line region (BLR) radius and the luminosity of the active galactic nucleus (AGN). Specifically, we have carried out two-dimensional surface brightness decompositions of the host galaxies of nine new AGNs imaged with the Hubble Space Telescope Wide Field Camera 3. The surface brightness decompositions allow us to create ''AGN-free'' images of the galaxies, from which we measure the starlight contribution to the optical luminosity measured through the ground-based spectroscopic aperture. We also incorporate 20 new reverberation-mapping measurements of the H{beta} time lag, which is assumed to yield the average H{beta} BLR radius. The final sample includes 41 AGNs covering four orders of magnitude in luminosity. The additions and updates incorporated here primarily affect the low-luminosity end of the R{sub BLR}-L relationship. The best fit to the relationship using a Bayesian analysis finds a slope of {alpha}= 0.533{sup +0.035}{sub -0.033}, consistent with previous work and with simple photoionization arguments. Only two AGNs appear to be outliers from the relationship, but both of them have monitoring light curves that raise doubt regarding the accuracy of their reported time lags. The scatter around the relationship is found to be 0.19more » {+-} 0.02 dex, but would be decreased to 0.13 dex by the removal of these two suspect measurements. A large fraction of the remaining scatter in the relationship is likely due to the inaccurate distances to the AGN host galaxies. Our results help support the possibility that the R{sub BLR}-L relationship could potentially be used to turn the BLRs of AGNs into standardizable candles. This would allow the cosmological expansion of the universe to be probed by a separate population of objects, and over a larger range of redshifts.« lessread more
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On possible proxies of AGN light-curves cadence selection in future time domain surveys
A. Kovacevic,A. Kovacevic,D. Ilic,D. Ilic,Luka Č. Popović,Luka Č. Popović,Viktor Radović,Isidora Jankov,Ilsang Yoon,Neven Caplar,Iva Cvorovic-Hajdinjak,Saša Simić +11 more
TL;DR: In this paper, a multiple-regression model was proposed to measure the cadence effects on active galactic nuclei (AGN) variability-observables (time-lags, periodicity, and structure function).
Journal ArticleDOI
Measuring the AGN sublimation radius with a new approach: reverberation mapping of the broad line polarization.
TL;DR: In this article, an observational method for measurements of the equatorial scattering region radius using variability in the polarized broad lines in Type 1 active galactic nuclei (AGNs) is presented.
Journal ArticleDOI
Reverberation mapping of AGNs through continuum polarization
TL;DR: In this article, the authors used the delay between polarized and unpolarized light to constrain the size and geometry of the broad line region in active galactic nuclei (AGNs) and verify that meaningful results can be expected from observations using this technique.
Journal ArticleDOI
Hunting for the nature of the enigmatic narrow-line Seyfert 1 galaxy PKS 2004-447
Marco Berton,Marco Berton,G. Peluso,G. Peluso,Paola Marziani,Stefanie Komossa,Luigi Foschini,Stefano Ciroi,Sina Chen,Enrico Congiu,Luigi C. Gallo,I. Björklund,L. Crepaldi,F. Di Mille,Emilia Järvelä,Jari Kotilainen,A. Kreikenbohm,A. Kreikenbohm,Nidia Morrell,P. Romano,E. Sani,Giacomo Terreran,Merja Tornikoski,S. Vercellone,A. Vietri +24 more
TL;DR: In this paper, a set of spectroscopic observations of PKS 2004-447 is presented, aimed at carefully measuring its black hole mass and Eddington ratio, determining the properties of its emission lines, and characterizing its long term variability.
Posted Content
Quasars in the 4D Eigenvector 1 Context: A stroll down memory lane
Jack W. Sulentic,Paola Marziani +1 more
TL;DR: The 4D eigenvector 1 context provides a surrogate H-R Diagram for quasars with a source main sequence driven by Eddington ratio convolved with line-of-sight orientation as discussed by the authors.
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