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The curious activity in the nucleus of NGC 4151 : jet interaction causing variability? / Williams, D. R. A.; Baldi, R. D.; McHardy, I. M.; Beswick, R. J.; Panessa, F.; May, D.; Moldón, J.; Argo, M. K.; Bruni, G.; Dullo, B. T.; Knapen, J. H.; Brinks, E.; Fenech, D. M.; Mundell, C. G.; Muxlow, T. W. B.; Pahari, M.; Westcott, J.

In: Monthly Notices of the Royal Astronomical Society, 15.04.2020.

Research output: Contribution to journalArticle

Harvard

Williams, DRA, Baldi, RD, McHardy, IM, Beswick, RJ, Panessa, F, May, D, Moldón, J, Argo, MK, Bruni, G, Dullo, BT, Knapen, JH, Brinks, E, Fenech, DM, Mundell, CG, Muxlow, TWB, Pahari, M & Westcott, J 2020, 'The curious activity in the nucleus of NGC 4151: jet interaction causing variability?', Monthly Notices of the Royal Astronomical Society.

APA

Williams, D. R. A., Baldi, R. D., McHardy, I. M., Beswick, R. J., Panessa, F., May, D., Moldón, J., Argo, M. K., Bruni, G., Dullo, B. T., Knapen, J. H., Brinks, E., Fenech, D. M., Mundell, C. G., Muxlow, T. W. B., Pahari, M., & Westcott, J. (Accepted/In press). The curious activity in the nucleus of NGC 4151: jet interaction causing variability? Monthly Notices of the Royal Astronomical Society.

Vancouver

Author

Williams, D. R. A. ; Baldi, R. D. ; McHardy, I. M. ; Beswick, R. J. ; Panessa, F. ; May, D. ; Moldón, J. ; Argo, M. K. ; Bruni, G. ; Dullo, B. T. ; Knapen, J. H. ; Brinks, E. ; Fenech, D. M. ; Mundell, C. G. ; Muxlow, T. W. B. ; Pahari, M. ; Westcott, J. / The curious activity in the nucleus of NGC 4151 : jet interaction causing variability?. In: Monthly Notices of the Royal Astronomical Society. 2020.

Bibtex

@article{080f8c1746e14c34901ffb3a0f5f690a,
title = "The curious activity in the nucleus of NGC 4151: jet interaction causing variability?",
abstract = "A key characteristic of many active galactic nuclei (AGN) is their variability, but its origin is poorly understood, especially in the radio domain. Williams et al. (2017) reported a ~50 per cent increase in peak flux density of the AGN in the Seyfert galaxy NGC 4151 at 1.5 GHz with the e-MERLIN array. We present new high resolution e-MERLIN observations at 5 GHz and compare these to archival MERLIN observations to investigate the reported variability. Our new observations allow us to probe the nuclear region at a factor three times higher-resolution than the previous e-MERLIN study. We separate the core component, C4, into three separate components: C4W, C4E and X. The AGN is thought to reside in component C4W, but this component has remained constant between epochs within uncertainties. However, we find that the Eastern-most component, C4E, has increased in peak flux density from 19.35$\pm$1.10 to 37.09$\pm$1.86 mJy/beam, representing a 8.2 sigma increase on the MERLIN observations. We attribute this peak flux density increase to continued interaction between the jet and the emission line region (ELR), observed for the first time in a low-luminosity AGN such as NGC 4151. We identify discrete resolved components at 5 GHz along the jet axis, which we interpret as areas of jet-ELR interaction. ",
keywords = "astro-ph.GA, astro-ph.HE",
author = "Williams, {D. R. A.} and Baldi, {R. D.} and McHardy, {I. M.} and Beswick, {R. J.} and F. Panessa and D. May and J. Mold{\'o}n and Argo, {M. K.} and G. Bruni and Dullo, {B. T.} and Knapen, {J. H.} and E. Brinks and Fenech, {D. M.} and Mundell, {C. G.} and Muxlow, {T. W. B.} and M. Pahari and J. Westcott",
note = "9 pages, 3 figures, 1 table, accepted to MNRAS",
year = "2020",
month = apr,
day = "15",
language = "English",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",

}

RIS

TY - JOUR

T1 - The curious activity in the nucleus of NGC 4151

T2 - jet interaction causing variability?

AU - Williams, D. R. A.

AU - Baldi, R. D.

AU - McHardy, I. M.

AU - Beswick, R. J.

AU - Panessa, F.

AU - May, D.

AU - Moldón, J.

AU - Argo, M. K.

AU - Bruni, G.

AU - Dullo, B. T.

AU - Knapen, J. H.

AU - Brinks, E.

AU - Fenech, D. M.

AU - Mundell, C. G.

AU - Muxlow, T. W. B.

AU - Pahari, M.

AU - Westcott, J.

N1 - 9 pages, 3 figures, 1 table, accepted to MNRAS

PY - 2020/4/15

Y1 - 2020/4/15

N2 - A key characteristic of many active galactic nuclei (AGN) is their variability, but its origin is poorly understood, especially in the radio domain. Williams et al. (2017) reported a ~50 per cent increase in peak flux density of the AGN in the Seyfert galaxy NGC 4151 at 1.5 GHz with the e-MERLIN array. We present new high resolution e-MERLIN observations at 5 GHz and compare these to archival MERLIN observations to investigate the reported variability. Our new observations allow us to probe the nuclear region at a factor three times higher-resolution than the previous e-MERLIN study. We separate the core component, C4, into three separate components: C4W, C4E and X. The AGN is thought to reside in component C4W, but this component has remained constant between epochs within uncertainties. However, we find that the Eastern-most component, C4E, has increased in peak flux density from 19.35$\pm$1.10 to 37.09$\pm$1.86 mJy/beam, representing a 8.2 sigma increase on the MERLIN observations. We attribute this peak flux density increase to continued interaction between the jet and the emission line region (ELR), observed for the first time in a low-luminosity AGN such as NGC 4151. We identify discrete resolved components at 5 GHz along the jet axis, which we interpret as areas of jet-ELR interaction.

AB - A key characteristic of many active galactic nuclei (AGN) is their variability, but its origin is poorly understood, especially in the radio domain. Williams et al. (2017) reported a ~50 per cent increase in peak flux density of the AGN in the Seyfert galaxy NGC 4151 at 1.5 GHz with the e-MERLIN array. We present new high resolution e-MERLIN observations at 5 GHz and compare these to archival MERLIN observations to investigate the reported variability. Our new observations allow us to probe the nuclear region at a factor three times higher-resolution than the previous e-MERLIN study. We separate the core component, C4, into three separate components: C4W, C4E and X. The AGN is thought to reside in component C4W, but this component has remained constant between epochs within uncertainties. However, we find that the Eastern-most component, C4E, has increased in peak flux density from 19.35$\pm$1.10 to 37.09$\pm$1.86 mJy/beam, representing a 8.2 sigma increase on the MERLIN observations. We attribute this peak flux density increase to continued interaction between the jet and the emission line region (ELR), observed for the first time in a low-luminosity AGN such as NGC 4151. We identify discrete resolved components at 5 GHz along the jet axis, which we interpret as areas of jet-ELR interaction.

KW - astro-ph.GA

KW - astro-ph.HE

M3 - Article

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

ER -