J/A+A/638/A13 NGC 3516 optical flare (Ilic+, 2020)
A flare in the optical spotted in the changing-look Seyfert NGC 3516.
Ilic D., Oknyansky V., Popovic L.C., Tsygankov S.S., Belinski A.A.,
Tatarnikov A.M., Dodin A.V., Shatsky N.I., Ikonnikova N.P., Rakic N.,
Kovacevic A., Marceta-Mandic S., Burlak M.A., Mishin E.O., Metlova N.V.,
Potanin S.A., Zheltoukhov S.G.
<Astron. Astrophys. 638, A13 (2020)>
=2020A&A...638A..13I 2020A&A...638A..13I (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Galaxies, Seyfert ; Photometry, UBV
Keywords: line: profiles - galaxies: active - galaxies: Seyfert -
quasars: individual: NGC 3516 - quasars: emission lines
Abstract:
We present observations from the short-term intensive optical campaign
(from September 2019 to January 2020) of the changing-look Seyfert
NGC 3516. This active galactic nucleus is known to have strong optical
variability and has changed its type in the past. It has been in the
low-activity state in the optical since 2013, with some rebrightening
from the end of 2015 to the beginning of 2016, after which it remained
dormant.
We aim to study the photometric and spectral variability of NGC 3516
from the new observations in U- and B-bands and examine the profiles
of the optical broad emission lines in order to demonstrate that this
object may be entering a new state of activity.
NGC 3516 has been monitored intensively for the past 4 months with an
automated telescope in U and B filters, enabling accurate photometry
of 0.01 precision. Spectral observations were triggered when an
increase in brightness was spotted. We support our analysis of
past-episodes of violent variability with the UV and X-ray long-term
light curves constructed from the archival Swift/UVOT and Swift/XRT
data.
An increase of the photometric magnitude is seen in both U and B
filters to a maximum amplitude of 0.25mag and 0.11mag, respectively.
During the flare, we observe stronger forbidden high-ionization iron
lines ([FeVII] and [FeX]) than reported before, as well as the
complex broad Hα and Hβ lines. This is especially seen in
Hα, which appears to be double-peaked. It seems that a very
broad component of ∼10000km/s in width in the Balmer lines is
appearing. The trends in the optical, UV, and X-ray light curves are
similar, with the amplitudes of variability being significantly larger
in the case of UV and X-ray bands.
The increase of the continuum emission, the variability of the coronal
lines, and the very broad component in the Balmer lines may indicate
that the AGN of NGC 3516 is finally leaving the low-activity state in
which it has been for the last ∼3 years.
Description:
The intensive photometric monitoring was performed in U and B filters
from 2019 Sept 16 to 2020 Jan 04 with the RC600, a new automated
telescope of the Caucasus Mountain Observatory at the Sternberg
Astronomical Institute (SAI CMO) of Moscow State University.
Objects:
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RA (2000) DE Designation(s)
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11 06 47.46 +72 34 07.2 NGC 3516 = UGC 6153
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
figure1.dat 18 209 *Long-term photometric optical light curves in B
magnitude (reduced to the same aperture of 10")
figure2.dat 38 39 *Short-term light curves in U and B bands (aperture
size 6.7")
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Note on figure1.dat: from the SAI Crimea campaign (till MJD 58698.32) and from
this paper (SAI CMO, after MJD 58746.54).
Note on figure2.dat : from the high-cadence monitoring campaign from 2019
Sept 16 to 2020 Jan 4.
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See also:
J/ApJ/828/78 : Optical monitoring of the Seyfert I NGC 3516 (Noda+, 2016)
Byte-by-byte Description of file: figure1.dat
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Bytes Format Units Label Explanations
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1- 8 F8.2 d MJD Modified Julian Date (JD-2400000)
13- 18 F6.3 mag Bmag B magnitude in the aperture size 10"
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Byte-by-byte Description of file: figure2.dat
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Bytes Format Units Label Explanations
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1- 8 F8.2 d MJD Modified Julian Date (JD-2400000)
17- 22 F6.3 mag Bmag ? B magnitude in the aperture size 6.7" (1)
33- 38 F6.3 mag Umag ? U magnitude in the aperture size 6.7" (1)
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Note (1): The errors are 0.01 mag for both magnitudes.
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Acknowledgements:
Dragana Ilic, dilic(at)matf.bg.ac.rs
(End) Patricia Vannier [CDS] 10-Apr-2020