The Central Engine of Low-luminosity Radio Galaxy 3C 270 (NGC 4261)

We present the polarization spectra of the nucleus of 3C 270. We confirm that the polarization angles of both the continuum and the emission lines are close to perpendicular to the jet direction after careful correction of interstellar polarization, which indicates polar scattering. The Stokes flux...

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Main Authors: Chengzhang Jiang, Robert Antonucci, J. A. Acosta-Pulido, Patrick Ogle
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
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Online Access:https://doi.org/10.3847/1538-4357/addc5a
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author Chengzhang Jiang
Robert Antonucci
J. A. Acosta-Pulido
Patrick Ogle
author_facet Chengzhang Jiang
Robert Antonucci
J. A. Acosta-Pulido
Patrick Ogle
author_sort Chengzhang Jiang
collection DOAJ
description We present the polarization spectra of the nucleus of 3C 270. We confirm that the polarization angles of both the continuum and the emission lines are close to perpendicular to the jet direction after careful correction of interstellar polarization, which indicates polar scattering. The Stokes flux spectrum resembles the total flux spectrum, with no need for a broad component from the broad-line region. Over 94% of a sample of Seyfert I broad-line profiles would be significantly detected if present in our polarized flux spectrum. We favor the hypothesis that we are observing the continuum including any contribution from radiatively inefficient accretion flow and beamed synchrotron instead of a big blue bump, as well as the innermost narrow-line region, through reflection. This makes 3C 270 the third known case, after NGC 4258 and Centaurus A, where only narrow lines (and the continuum, if present) are scattered, with no evidence of an underlying big blue bump.
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spelling doaj-art-169b64a417e444b59dbd87f0c46c3cb22025-08-20T02:37:25ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01987211810.3847/1538-4357/addc5aThe Central Engine of Low-luminosity Radio Galaxy 3C 270 (NGC 4261)Chengzhang Jiang0https://orcid.org/0009-0008-2985-0726Robert Antonucci1J. A. Acosta-Pulido2https://orcid.org/0000-0002-0433-9656Patrick Ogle3https://orcid.org/0000-0002-3471-981XDepartment of Physics and Astronomy, University of California , Riverside, 900 University Ave., Riverside, CA 92521, USA ; cjian079@ucr.eduDepartment of Physics, University of California , Santa Barbara, CA 93106-9530, USAInstituto de Astrofísica de Canarias , Calle Vía Láctea, s/n, E-38205, La Laguna, Tenerife, Spain; Departamento de Astrofísica, Universidad de La Laguna , E-38206, La Laguna, Tenerife, SpainSpace Telescope Science Institute Baltimore , MD 21218, USAWe present the polarization spectra of the nucleus of 3C 270. We confirm that the polarization angles of both the continuum and the emission lines are close to perpendicular to the jet direction after careful correction of interstellar polarization, which indicates polar scattering. The Stokes flux spectrum resembles the total flux spectrum, with no need for a broad component from the broad-line region. Over 94% of a sample of Seyfert I broad-line profiles would be significantly detected if present in our polarized flux spectrum. We favor the hypothesis that we are observing the continuum including any contribution from radiatively inefficient accretion flow and beamed synchrotron instead of a big blue bump, as well as the innermost narrow-line region, through reflection. This makes 3C 270 the third known case, after NGC 4258 and Centaurus A, where only narrow lines (and the continuum, if present) are scattered, with no evidence of an underlying big blue bump.https://doi.org/10.3847/1538-4357/addc5aLow-luminosity active galactic nuclei
spellingShingle Chengzhang Jiang
Robert Antonucci
J. A. Acosta-Pulido
Patrick Ogle
The Central Engine of Low-luminosity Radio Galaxy 3C 270 (NGC 4261)
The Astrophysical Journal
Low-luminosity active galactic nuclei
title The Central Engine of Low-luminosity Radio Galaxy 3C 270 (NGC 4261)
title_full The Central Engine of Low-luminosity Radio Galaxy 3C 270 (NGC 4261)
title_fullStr The Central Engine of Low-luminosity Radio Galaxy 3C 270 (NGC 4261)
title_full_unstemmed The Central Engine of Low-luminosity Radio Galaxy 3C 270 (NGC 4261)
title_short The Central Engine of Low-luminosity Radio Galaxy 3C 270 (NGC 4261)
title_sort central engine of low luminosity radio galaxy 3c 270 ngc 4261
topic Low-luminosity active galactic nuclei
url https://doi.org/10.3847/1538-4357/addc5a
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