The variability of Seyfert 1.8 and 1.9 galaxies at 1.6 microns

A. C. Quillen; Shanna Shaked; A. Alonso-Herrero; Colleen McDonald; Ariane Lee; M. J. Rieke; G. H. Rieke

doi:10.1086/312563

The variability of Seyfert 1.8 and 1.9 galaxies at 1.6 microns

A. C. Quillen, Shanna Shaked, A. Alonso-Herrero, Colleen McDonald, Ariane Lee, M. J. Rieke, G. H. Rieke

Research output: Contribution to journal › Article › peer-review

10 Scopus citations

Abstract

We present a study of Seyfert 1.5-2.0 galaxies observed at two epochs with the Rubble Space Telescope (HST) at 1.6 μm. We find that unresolved nuclear emission from nine of 14 nuclei varies at the level of 10%-40% on timescales of 0.7-14 months, depending upon the galaxy. A control sample of Seyfert galaxies lacking unresolved sources and galaxies lacking Seyfert nuclei show less than 3% instrumental variation in equivalent aperture measurements. This proves that the unresolved sources are nonstellar and associated with the central parsecs of active galactic nuclei. Unresolved sources in Seyfert 1.8 and 1.9 galaxies are not usually detected in HST optical surveys; however, high angular resolution infrared observations will provide a way to measure time delays in these galaxies.

Original language	English (US)
Pages (from-to)	L17-L20
Journal	Astrophysical Journal
Volume	532
Issue number	1 PART 2
DOIs	https://doi.org/10.1086/312563
State	Published - Mar 20 2000

Keywords

Galaxies: Seyfert
Galaxies: active
Galaxies: nuclei
Infrared: galaxies

ASJC Scopus subject areas

Astronomy and Astrophysics
Space and Planetary Science

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10.1086/312563

Cite this

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title = "The variability of Seyfert 1.8 and 1.9 galaxies at 1.6 microns",

abstract = "We present a study of Seyfert 1.5-2.0 galaxies observed at two epochs with the Rubble Space Telescope (HST) at 1.6 μm. We find that unresolved nuclear emission from nine of 14 nuclei varies at the level of 10%-40% on timescales of 0.7-14 months, depending upon the galaxy. A control sample of Seyfert galaxies lacking unresolved sources and galaxies lacking Seyfert nuclei show less than 3% instrumental variation in equivalent aperture measurements. This proves that the unresolved sources are nonstellar and associated with the central parsecs of active galactic nuclei. Unresolved sources in Seyfert 1.8 and 1.9 galaxies are not usually detected in HST optical surveys; however, high angular resolution infrared observations will provide a way to measure time delays in these galaxies.",

keywords = "Galaxies: Seyfert, Galaxies: active, Galaxies: nuclei, Infrared: galaxies",

author = "Quillen, {A. C.} and Shanna Shaked and A. Alonso-Herrero and Colleen McDonald and Ariane Lee and Rieke, {M. J.} and Rieke, {G. H.}",

note = "Funding Information: We thank the referee, Ski Antonnuci, for comments which have improved this Letter. We thank Brad Peterson and Chien Peng for helpful discussions on this work. Support for this work was provided by NASA through grant GO-07869.01-96A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. We also acknowledge support from NASA projects NAG5-3359 and NAG5-3042 and from JPL contract 961633.",

year = "2000",

month = mar,

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doi = "10.1086/312563",

language = "English (US)",

volume = "532",

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T1 - The variability of Seyfert 1.8 and 1.9 galaxies at 1.6 microns

AU - Quillen, A. C.

AU - Shaked, Shanna

AU - Alonso-Herrero, A.

AU - McDonald, Colleen

AU - Lee, Ariane

AU - Rieke, M. J.

AU - Rieke, G. H.

N1 - Funding Information: We thank the referee, Ski Antonnuci, for comments which have improved this Letter. We thank Brad Peterson and Chien Peng for helpful discussions on this work. Support for this work was provided by NASA through grant GO-07869.01-96A from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract NAS5-26555. We also acknowledge support from NASA projects NAG5-3359 and NAG5-3042 and from JPL contract 961633.

PY - 2000/3/20

Y1 - 2000/3/20

N2 - We present a study of Seyfert 1.5-2.0 galaxies observed at two epochs with the Rubble Space Telescope (HST) at 1.6 μm. We find that unresolved nuclear emission from nine of 14 nuclei varies at the level of 10%-40% on timescales of 0.7-14 months, depending upon the galaxy. A control sample of Seyfert galaxies lacking unresolved sources and galaxies lacking Seyfert nuclei show less than 3% instrumental variation in equivalent aperture measurements. This proves that the unresolved sources are nonstellar and associated with the central parsecs of active galactic nuclei. Unresolved sources in Seyfert 1.8 and 1.9 galaxies are not usually detected in HST optical surveys; however, high angular resolution infrared observations will provide a way to measure time delays in these galaxies.

AB - We present a study of Seyfert 1.5-2.0 galaxies observed at two epochs with the Rubble Space Telescope (HST) at 1.6 μm. We find that unresolved nuclear emission from nine of 14 nuclei varies at the level of 10%-40% on timescales of 0.7-14 months, depending upon the galaxy. A control sample of Seyfert galaxies lacking unresolved sources and galaxies lacking Seyfert nuclei show less than 3% instrumental variation in equivalent aperture measurements. This proves that the unresolved sources are nonstellar and associated with the central parsecs of active galactic nuclei. Unresolved sources in Seyfert 1.8 and 1.9 galaxies are not usually detected in HST optical surveys; however, high angular resolution infrared observations will provide a way to measure time delays in these galaxies.

KW - Galaxies: Seyfert

KW - Galaxies: active

KW - Galaxies: nuclei

KW - Infrared: galaxies

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JO - Astrophysical Journal

JF - Astrophysical Journal

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ER -

The variability of Seyfert 1.8 and 1.9 galaxies at 1.6 microns

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Keywords

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