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Title: Dust Reverberation of 3C 273: Torus Structure and Lag–Luminosity Relation

Abstract

We monitored the z = 0.158 quasar 3C 273 between 2015 and 2019 in the optical (BVrz) and near-infrared (JHK) with the aim to perform dust reverberation mapping. Accounting for host galaxy and accretion disk contributions, we obtained pure dust light curves in JHK. Cross correlations between the V band and the dust light curves yield an average rest-frame delay for the hot dust of τ {sub cent} ∼ 410 days. This is a factor of two shorter than that expected from the the dust ring radius R {sub x} ∼ 900 lt-day reported from interferometric studies. The dust covering factor (CF) is about 8%, much smaller than that predicted from the half covering angle of 45° found for active galactic nuclei (AGNs). We analyze the asymmetric shape of the correlation functions and explore whether an inclined biconical bowl-shaped dust torus geometry could bring these findings (τ {sub cent}, R {sub x} and CF) into a consistent picture. The hot varying dust emission originates from the edge of the bowl rim with a small covering angle 40° < θ < 45°, and we see only the near side of the biconus. Such a dust gloriole with R {sub x} = 900 ± 200 lt-day and an inclination 12° matches the data remarkably well. Comparingmore » the results of 3C 273 with literature for less luminous AGN, we find a lag–luminosity relation τ ∝ L {sup α} with α = 0.33–0.40, flatter than the widely adopted relation with α ∼ 0.5. We address several explanations for the new lag–luminosity relation.« less

Authors:
; ; ; ;  [1];  [2];  [3];  [4];  [5];  [6]
  1. Astronomisches Institut Ruhr-Universität Bochum, Universitätsstr. 150, D-44801 Bochum (Germany)
  2. Institute for Astronomy, 640 North A’ohōkū Place, Hilo, HI 96720-2700 (United States)
  3. Universidad Católica del Norte, Antofagasta (Chile)
  4. Institut für Astrophysik, Universität Göttingen, Friedrich-Hund Platz 1, D-37077 Göttingen (Germany)
  5. Physics Department and the Haifa Research Center for Theoretical Physics and Astrophysics, University of Haifa (Israel)
  6. School of Physics & Astronomy and the Wise Observatory, The Raymond and Beverly Sackler Faculty of Exact Sciences Tel-Aviv University (Israel)
Publication Date:
OSTI Identifier:
23013229
Resource Type:
Journal Article
Journal Name:
Astronomical Journal (New York, N.Y. Online)
Additional Journal Information:
Journal Volume: 159; Journal Issue: 6; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1538-3881
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; ASYMMETRY; CORRELATIONS; COSMIC DUST; EMISSION; GALAXIES; GALAXY NUCLEI; INCLINATION; LUMINOSITY; QUASARS

Citation Formats

Figaredo, Catalina Sobrino, Haas, Martin, Ramolla, Michael, Chini, Rolf, Blex, Julia, Hodapp, Klaus Werner, Murphy, Miguel, Kollatschny, Wolfram, Chelouche, Doron, and Kaspi, Shai. Dust Reverberation of 3C 273: Torus Structure and Lag–Luminosity Relation. United States: N. p., 2020. Web. doi:10.3847/1538-3881/AB89B1.
Figaredo, Catalina Sobrino, Haas, Martin, Ramolla, Michael, Chini, Rolf, Blex, Julia, Hodapp, Klaus Werner, Murphy, Miguel, Kollatschny, Wolfram, Chelouche, Doron, & Kaspi, Shai. Dust Reverberation of 3C 273: Torus Structure and Lag–Luminosity Relation. United States. https://doi.org/10.3847/1538-3881/AB89B1
Figaredo, Catalina Sobrino, Haas, Martin, Ramolla, Michael, Chini, Rolf, Blex, Julia, Hodapp, Klaus Werner, Murphy, Miguel, Kollatschny, Wolfram, Chelouche, Doron, and Kaspi, Shai. 2020. "Dust Reverberation of 3C 273: Torus Structure and Lag–Luminosity Relation". United States. https://doi.org/10.3847/1538-3881/AB89B1.
@article{osti_23013229,
title = {Dust Reverberation of 3C 273: Torus Structure and Lag–Luminosity Relation},
author = {Figaredo, Catalina Sobrino and Haas, Martin and Ramolla, Michael and Chini, Rolf and Blex, Julia and Hodapp, Klaus Werner and Murphy, Miguel and Kollatschny, Wolfram and Chelouche, Doron and Kaspi, Shai},
abstractNote = {We monitored the z = 0.158 quasar 3C 273 between 2015 and 2019 in the optical (BVrz) and near-infrared (JHK) with the aim to perform dust reverberation mapping. Accounting for host galaxy and accretion disk contributions, we obtained pure dust light curves in JHK. Cross correlations between the V band and the dust light curves yield an average rest-frame delay for the hot dust of τ {sub cent} ∼ 410 days. This is a factor of two shorter than that expected from the the dust ring radius R {sub x} ∼ 900 lt-day reported from interferometric studies. The dust covering factor (CF) is about 8%, much smaller than that predicted from the half covering angle of 45° found for active galactic nuclei (AGNs). We analyze the asymmetric shape of the correlation functions and explore whether an inclined biconical bowl-shaped dust torus geometry could bring these findings (τ {sub cent}, R {sub x} and CF) into a consistent picture. The hot varying dust emission originates from the edge of the bowl rim with a small covering angle 40° < θ < 45°, and we see only the near side of the biconus. Such a dust gloriole with R {sub x} = 900 ± 200 lt-day and an inclination 12° matches the data remarkably well. Comparing the results of 3C 273 with literature for less luminous AGN, we find a lag–luminosity relation τ ∝ L {sup α} with α = 0.33–0.40, flatter than the widely adopted relation with α ∼ 0.5. We address several explanations for the new lag–luminosity relation.},
doi = {10.3847/1538-3881/AB89B1},
url = {https://www.osti.gov/biblio/23013229}, journal = {Astronomical Journal (New York, N.Y. Online)},
issn = {1538-3881},
number = 6,
volume = 159,
place = {United States},
year = {Mon Jun 01 00:00:00 EDT 2020},
month = {Mon Jun 01 00:00:00 EDT 2020}
}