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A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states

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A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states. / Laha, Sibasish; Meyer, Eileen; Roychowdhury, Agniva et al.
In: Astrophysical Journal, Vol. 931, No. 1, 5, 18.05.2022.

Research output: Contribution to Journal/MagazineJournal articlepeer-review

Harvard

Laha, S, Meyer, E, Roychowdhury, A, Becerra, JG, Acosta-Pulido, JA, Thapa, A, Ghosh, R, Behar, E, Gallo, LC, Kriss, GA, Panessa, F, Bianchi, S, La Franca, F, Scepi, N, Begelman, MC, Longinotti, AL, Lusso, E, Oates, S, Nicholl, M & Cenko, SB 2022, 'A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states', Astrophysical Journal, vol. 931, no. 1, 5. https://doi.org/10.3847/1538-4357/ac63aa

APA

Laha, S., Meyer, E., Roychowdhury, A., Becerra, J. G., Acosta-Pulido, J. A., Thapa, A., Ghosh, R., Behar, E., Gallo, L. C., Kriss, G. A., Panessa, F., Bianchi, S., La Franca, F., Scepi, N., Begelman, M. C., Longinotti, A. L., Lusso, E., Oates, S., Nicholl, M., & Cenko, S. B. (2022). A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states. Astrophysical Journal, 931(1), Article 5. https://doi.org/10.3847/1538-4357/ac63aa

Vancouver

Laha S, Meyer E, Roychowdhury A, Becerra JG, Acosta-Pulido JA, Thapa A et al. A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states. Astrophysical Journal. 2022 May 18;931(1):5. doi: 10.3847/1538-4357/ac63aa

Author

Laha, Sibasish ; Meyer, Eileen ; Roychowdhury, Agniva et al. / A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states. In: Astrophysical Journal. 2022 ; Vol. 931, No. 1.

Bibtex

@article{e1bca485a0b841118496f6cd81910a6e,
title = "A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states",
abstract = "The nearby type-II AGN 1ES1927+654 went through a violent changing-look (CL) event beginning December 2017 during which the optical and UV fluxes increased by four magnitudes over a few months, and broad emission lines newly appeared in the optical/UV. By July 2018 the X-ray coronal emission had completely vanished, only to reappear a few months later. In this work we report the evolution of the radio, optical, UV and X-rays from the pre-flare state through mid-2021 with new and archival data from the Very Long Baseline Array (VLBA), the European VLBI Network, the Very Large Array (VLA), the Telescopio Nazionale Galileo (TNG), Gran Telescopio Canarias (GTC), The Neil Gehrels Swift observatory and XMM-Newton. The main results from our work are: (1) The source has returned to its pre-CL state in optical, UV, and X-ray; the disk-corona relation has been re-established as has been in the pre-CL state, with an $\alpha_{\rm OX}\sim 1.02$. The optical spectra are dominated by narrow emission lines. (2) The UV light curve follows a shallower slope of $\propto t^{-0.91\pm 0.04}$ compared to that predicted by a tidal disruption event. We conjecture that a magnetic flux inversion event is the possible cause for this enigmatic event. (3) The compact radio emission which we tracked in the pre-CL (2014), during CL (2018) and post-CL(2021) at spatial scales $<1$ pc was at its lowest level during the changing look event in 2018, nearly contemporaneous with a low $2-10$ keV emission. The radio to X-ray ratio of the compact source $L_{\rm Radio}/L_{\rm X-ray}\sim 10^{-5.5}$, follows the Gudel-Benz relation, typically found in coronally active stars, and several AGN. (4) We do not detect any presence of nascent jets at the spatial scales of $\sim 5-10$ pc....",
author = "Sibasish Laha and Eileen Meyer and Agniva Roychowdhury and Becerra, {Josefa G.} and Acosta-Pulido, {J. A.} and Aditya Thapa and Ritesh Ghosh and Ehud Behar and Gallo, {Luigi C.} and Kriss, {Gerard A.} and Francesca Panessa and Stefano Bianchi and {La Franca}, Fabio and Nicolas Scepi and Begelman, {Mitchell C.} and Longinotti, {Anna Lia} and Elisabeta Lusso and Samantha Oates and Matt Nicholl and Cenko, {S. Bradley}",
year = "2022",
month = may,
day = "18",
doi = "10.3847/1538-4357/ac63aa",
language = "English",
volume = "931",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "Institute of Physics Publishing",
number = "1",

}

RIS

TY - JOUR

T1 - A radio, optical, UV and X-ray view of the enigmatic changing look Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states

AU - Laha, Sibasish

AU - Meyer, Eileen

AU - Roychowdhury, Agniva

AU - Becerra, Josefa G.

AU - Acosta-Pulido, J. A.

AU - Thapa, Aditya

AU - Ghosh, Ritesh

AU - Behar, Ehud

AU - Gallo, Luigi C.

AU - Kriss, Gerard A.

AU - Panessa, Francesca

AU - Bianchi, Stefano

AU - La Franca, Fabio

AU - Scepi, Nicolas

AU - Begelman, Mitchell C.

AU - Longinotti, Anna Lia

AU - Lusso, Elisabeta

AU - Oates, Samantha

AU - Nicholl, Matt

AU - Cenko, S. Bradley

PY - 2022/5/18

Y1 - 2022/5/18

N2 - The nearby type-II AGN 1ES1927+654 went through a violent changing-look (CL) event beginning December 2017 during which the optical and UV fluxes increased by four magnitudes over a few months, and broad emission lines newly appeared in the optical/UV. By July 2018 the X-ray coronal emission had completely vanished, only to reappear a few months later. In this work we report the evolution of the radio, optical, UV and X-rays from the pre-flare state through mid-2021 with new and archival data from the Very Long Baseline Array (VLBA), the European VLBI Network, the Very Large Array (VLA), the Telescopio Nazionale Galileo (TNG), Gran Telescopio Canarias (GTC), The Neil Gehrels Swift observatory and XMM-Newton. The main results from our work are: (1) The source has returned to its pre-CL state in optical, UV, and X-ray; the disk-corona relation has been re-established as has been in the pre-CL state, with an $\alpha_{\rm OX}\sim 1.02$. The optical spectra are dominated by narrow emission lines. (2) The UV light curve follows a shallower slope of $\propto t^{-0.91\pm 0.04}$ compared to that predicted by a tidal disruption event. We conjecture that a magnetic flux inversion event is the possible cause for this enigmatic event. (3) The compact radio emission which we tracked in the pre-CL (2014), during CL (2018) and post-CL(2021) at spatial scales $<1$ pc was at its lowest level during the changing look event in 2018, nearly contemporaneous with a low $2-10$ keV emission. The radio to X-ray ratio of the compact source $L_{\rm Radio}/L_{\rm X-ray}\sim 10^{-5.5}$, follows the Gudel-Benz relation, typically found in coronally active stars, and several AGN. (4) We do not detect any presence of nascent jets at the spatial scales of $\sim 5-10$ pc....

AB - The nearby type-II AGN 1ES1927+654 went through a violent changing-look (CL) event beginning December 2017 during which the optical and UV fluxes increased by four magnitudes over a few months, and broad emission lines newly appeared in the optical/UV. By July 2018 the X-ray coronal emission had completely vanished, only to reappear a few months later. In this work we report the evolution of the radio, optical, UV and X-rays from the pre-flare state through mid-2021 with new and archival data from the Very Long Baseline Array (VLBA), the European VLBI Network, the Very Large Array (VLA), the Telescopio Nazionale Galileo (TNG), Gran Telescopio Canarias (GTC), The Neil Gehrels Swift observatory and XMM-Newton. The main results from our work are: (1) The source has returned to its pre-CL state in optical, UV, and X-ray; the disk-corona relation has been re-established as has been in the pre-CL state, with an $\alpha_{\rm OX}\sim 1.02$. The optical spectra are dominated by narrow emission lines. (2) The UV light curve follows a shallower slope of $\propto t^{-0.91\pm 0.04}$ compared to that predicted by a tidal disruption event. We conjecture that a magnetic flux inversion event is the possible cause for this enigmatic event. (3) The compact radio emission which we tracked in the pre-CL (2014), during CL (2018) and post-CL(2021) at spatial scales $<1$ pc was at its lowest level during the changing look event in 2018, nearly contemporaneous with a low $2-10$ keV emission. The radio to X-ray ratio of the compact source $L_{\rm Radio}/L_{\rm X-ray}\sim 10^{-5.5}$, follows the Gudel-Benz relation, typically found in coronally active stars, and several AGN. (4) We do not detect any presence of nascent jets at the spatial scales of $\sim 5-10$ pc....

U2 - 10.3847/1538-4357/ac63aa

DO - 10.3847/1538-4357/ac63aa

M3 - Journal article

VL - 931

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 1

M1 - 5

ER -