The lick agn monitoring project 2011: Fe II reverberation from the outer broad-line region

Aaron J. Barth, Anna Pancoast, Vardha N. Bennert, Brendon J. Brewer, Gabriela Canalizo, Alexei V. Filippenko, Elinor L. Gates, Jenny E. Greene, Weidong Li, Matthew A. Malkan, David J. Sand, Daniel Stern, Tommaso Treu, Jong Hak Woo, Roberto J. Assef, Hyun Jin Bae, Tabitha Buehler, S. Bradley Cenko, Kelsey I. Clubb, Michael C. CooperAleksandar M. Diamond-Stanic, Sebastian F. Hönig, Michael D. Joner, C. David Laney, Mariana S. Lazarova, A. M. Nierenberg, Jeffrey M. Silverman, Erik J. Tollerud, Jonelle L. Walsh

Research output: Contribution to journalArticle

63 Citations (Scopus)

Abstract

The prominent broad Fe II emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe II lines have met with only limited success. Here we report the detection of Fe II reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including Hβ and Fe II were measured by applying a fitting routine to decompose the spectra into several continuum and emission-line components, and we use cross-correlation techniques to determine the reverberation lags of the emission lines relative to V-band light curves. In both cases, the measured lag (τcen) of Fe II is longer than that of Hβ, although the inferred lags are somewhat sensitive to the choice of Fe II template used in the fit. For spectral decompositions done using the Fe II template of Véron-Cetty et al., we find τcen (Fe II)/τcen (Hβ) = 1.9 ± 0.6 in NGC 4593 and 1.5 ± 0.3 in Mrk 1511. The detection of highly correlated variations between Fe II and continuum emission demonstrates that the Fe II emission in these galaxies originates in photoionized gas, located predominantly in the outer portion of the broad-line region.

Original languageEnglish (US)
Article number128
JournalAstrophysical Journal
Volume769
Issue number2
DOIs
StatePublished - Jun 1 2013

Fingerprint

reverberation
time lag
monitoring
continuums
light curve
templates
galaxies
extremely high frequencies
active galactic nuclei
cross correlation
project
observatories
observatory
decomposition
gases
gas

Keywords

  • galaxies: active
  • galaxies: individual (Mrk 1511, NGC 4593)
  • galaxies: nuclei

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Barth, A. J., Pancoast, A., Bennert, V. N., Brewer, B. J., Canalizo, G., Filippenko, A. V., ... Walsh, J. L. (2013). The lick agn monitoring project 2011: Fe II reverberation from the outer broad-line region. Astrophysical Journal, 769(2), [128]. https://doi.org/10.1088/0004-637X/769/2/128

The lick agn monitoring project 2011 : Fe II reverberation from the outer broad-line region. / Barth, Aaron J.; Pancoast, Anna; Bennert, Vardha N.; Brewer, Brendon J.; Canalizo, Gabriela; Filippenko, Alexei V.; Gates, Elinor L.; Greene, Jenny E.; Li, Weidong; Malkan, Matthew A.; Sand, David J.; Stern, Daniel; Treu, Tommaso; Woo, Jong Hak; Assef, Roberto J.; Bae, Hyun Jin; Buehler, Tabitha; Cenko, S. Bradley; Clubb, Kelsey I.; Cooper, Michael C.; Diamond-Stanic, Aleksandar M.; Hönig, Sebastian F.; Joner, Michael D.; Laney, C. David; Lazarova, Mariana S.; Nierenberg, A. M.; Silverman, Jeffrey M.; Tollerud, Erik J.; Walsh, Jonelle L.

In: Astrophysical Journal, Vol. 769, No. 2, 128, 01.06.2013.

Research output: Contribution to journalArticle

Barth, AJ, Pancoast, A, Bennert, VN, Brewer, BJ, Canalizo, G, Filippenko, AV, Gates, EL, Greene, JE, Li, W, Malkan, MA, Sand, DJ, Stern, D, Treu, T, Woo, JH, Assef, RJ, Bae, HJ, Buehler, T, Cenko, SB, Clubb, KI, Cooper, MC, Diamond-Stanic, AM, Hönig, SF, Joner, MD, Laney, CD, Lazarova, MS, Nierenberg, AM, Silverman, JM, Tollerud, EJ & Walsh, JL 2013, 'The lick agn monitoring project 2011: Fe II reverberation from the outer broad-line region', Astrophysical Journal, vol. 769, no. 2, 128. https://doi.org/10.1088/0004-637X/769/2/128
Barth AJ, Pancoast A, Bennert VN, Brewer BJ, Canalizo G, Filippenko AV et al. The lick agn monitoring project 2011: Fe II reverberation from the outer broad-line region. Astrophysical Journal. 2013 Jun 1;769(2). 128. https://doi.org/10.1088/0004-637X/769/2/128
Barth, Aaron J. ; Pancoast, Anna ; Bennert, Vardha N. ; Brewer, Brendon J. ; Canalizo, Gabriela ; Filippenko, Alexei V. ; Gates, Elinor L. ; Greene, Jenny E. ; Li, Weidong ; Malkan, Matthew A. ; Sand, David J. ; Stern, Daniel ; Treu, Tommaso ; Woo, Jong Hak ; Assef, Roberto J. ; Bae, Hyun Jin ; Buehler, Tabitha ; Cenko, S. Bradley ; Clubb, Kelsey I. ; Cooper, Michael C. ; Diamond-Stanic, Aleksandar M. ; Hönig, Sebastian F. ; Joner, Michael D. ; Laney, C. David ; Lazarova, Mariana S. ; Nierenberg, A. M. ; Silverman, Jeffrey M. ; Tollerud, Erik J. ; Walsh, Jonelle L. / The lick agn monitoring project 2011 : Fe II reverberation from the outer broad-line region. In: Astrophysical Journal. 2013 ; Vol. 769, No. 2.
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AU - Barth, Aaron J.

AU - Pancoast, Anna

AU - Bennert, Vardha N.

AU - Brewer, Brendon J.

AU - Canalizo, Gabriela

AU - Filippenko, Alexei V.

AU - Gates, Elinor L.

AU - Greene, Jenny E.

AU - Li, Weidong

AU - Malkan, Matthew A.

AU - Sand, David J.

AU - Stern, Daniel

AU - Treu, Tommaso

AU - Woo, Jong Hak

AU - Assef, Roberto J.

AU - Bae, Hyun Jin

AU - Buehler, Tabitha

AU - Cenko, S. Bradley

AU - Clubb, Kelsey I.

AU - Cooper, Michael C.

AU - Diamond-Stanic, Aleksandar M.

AU - Hönig, Sebastian F.

AU - Joner, Michael D.

AU - Laney, C. David

AU - Lazarova, Mariana S.

AU - Nierenberg, A. M.

AU - Silverman, Jeffrey M.

AU - Tollerud, Erik J.

AU - Walsh, Jonelle L.

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N2 - The prominent broad Fe II emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe II lines have met with only limited success. Here we report the detection of Fe II reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including Hβ and Fe II were measured by applying a fitting routine to decompose the spectra into several continuum and emission-line components, and we use cross-correlation techniques to determine the reverberation lags of the emission lines relative to V-band light curves. In both cases, the measured lag (τcen) of Fe II is longer than that of Hβ, although the inferred lags are somewhat sensitive to the choice of Fe II template used in the fit. For spectral decompositions done using the Fe II template of Véron-Cetty et al., we find τcen (Fe II)/τcen (Hβ) = 1.9 ± 0.6 in NGC 4593 and 1.5 ± 0.3 in Mrk 1511. The detection of highly correlated variations between Fe II and continuum emission demonstrates that the Fe II emission in these galaxies originates in photoionized gas, located predominantly in the outer portion of the broad-line region.

AB - The prominent broad Fe II emission blends in the spectra of active galactic nuclei have been shown to vary in response to continuum variations, but past attempts to measure the reverberation lag time of the optical Fe II lines have met with only limited success. Here we report the detection of Fe II reverberation in two Seyfert 1 galaxies, NGC 4593 and Mrk 1511, based on data from a program carried out at Lick Observatory in Spring 2011. Light curves for emission lines including Hβ and Fe II were measured by applying a fitting routine to decompose the spectra into several continuum and emission-line components, and we use cross-correlation techniques to determine the reverberation lags of the emission lines relative to V-band light curves. In both cases, the measured lag (τcen) of Fe II is longer than that of Hβ, although the inferred lags are somewhat sensitive to the choice of Fe II template used in the fit. For spectral decompositions done using the Fe II template of Véron-Cetty et al., we find τcen (Fe II)/τcen (Hβ) = 1.9 ± 0.6 in NGC 4593 and 1.5 ± 0.3 in Mrk 1511. The detection of highly correlated variations between Fe II and continuum emission demonstrates that the Fe II emission in these galaxies originates in photoionized gas, located predominantly in the outer portion of the broad-line region.

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KW - galaxies: individual (Mrk 1511, NGC 4593)

KW - galaxies: nuclei

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