J/ApJ/828/78 Optical monitoring of the Seyfert I NGC 3516 (Noda+, 2016)
X-ray and optical correlation of Type I Seyfert NGC 3516 studied with Suzaku
and japanese ground-based telescopes.
Noda H., Minezaki T., Watanabe M., Kokubo M., Kawaguchi K., Itoh R.,
Morihana K., Saito Y., Nakao H., Imai M., Moritani Y., Takaki K.,
Kawabata M., Nakaoka T., Uemura M., Kawabata K., Yoshida M., Arai A.,
Takagi Y., Morokuma T., Doi M., Itoh Y., Yamada S., Nakazawa K.,
Fukazawa Y., Makishima K.
<Astrophys. J., 828, 78-78 (2016)>
=2016ApJ...828...78N 2016ApJ...828...78N (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Photometry, UBV
Keywords: galaxies: active; galaxies: individual: NGC 3516;
galaxies: Seyfert; X-rays: galaxies
Abstract:
From 2013 April to 2014 April, we performed X-ray and optical
simultaneous monitoring of the type 1.5 Seyfert galaxy NGC 3516. We
employed Suzaku and five Japanese ground-based telescopes-the Pirka,
Kiso Schmidt, Nayuta, MITSuME, and the Kanata telescopes. The Suzaku
observations were conducted seven times with various intervals ranging
from days or weeks to months, with an exposure of ∼50ks each. The
optical B-band observations not only covered those of Suzaku almost
simultaneously, but also followed the source as frequently as
possible. As a result, NGC 3516 was found in its faint phase with a
2-10keV flux of 0.21-2.70x10-11ergs/s/cm2. The 2-45keV X-ray
spectra were composed of a dominant variable hard power-law (PL)
continuum with a photon index of ∼1.7 and a non-relativistic
reflection component with a prominent Fe-Kα emission line.
Producing the B-band light curve by differential image photometry, we
found that the B-band flux changed by ∼2.7x10-11ergs/s/cm2, which
is comparable to the X-ray variation, and we detected a significant
flux correlation between the hard PL component in X-rays and the
B-band radiation, for the first time in NGC 3516. By examining their
correlation, we found that the X-ray flux preceded that in the B band
by 2.0-0.6+0.7 days (1σ error). Although this result
supports the X-ray reprocessing model, the derived lag is too large to
be explained by the standard view, which assumes a "lamppost"-type
X-ray illuminator located near a standard accretion disk. Our results
are better explained by assuming a hot accretion flow and a truncated
disk.
Description:
The X-ray monitoring observations of NGC 3516 were performed in the
Suzaku AO-8 cycle during 2013-2014. Specifically, NGC 3516 was
observed with Suzaku five times from 2013 April 10 to May 29, with
intervals of ∼1-2 weeks. Another pointing was carried out on November
7, and the last one on 2014 April 4, making a total of seven
observations, with various intervals from days to months.
The optical photometric monitoring observations of NGC 3516 were
performed by using the charge-coupled device (CCD) cameras installed
at the Pirka, MITSuME, Kiso Schmidt, Nayuta, and Kanata telescopes.
Simultaneous monitoring observations were performed at the same seven
epochs as the X-ray observations by Suzaku. In addition, from 2013
January to 2014 April, these telescopes densely monitored the source
even without simultaneous X-ray coverage, with a typical intervals of
∼1 day. In the present paper, we present the B-band and g'-band
photometric data, because the optical continuum emission of AGNs is
generally bluer than that of the host galaxy, thus ensuring better
sensitivity to the AGN signals.
Objects:
-------------------------------------------------
RA (ICRS) DE Designation(s)
-------------------------------------------------
11 06 47.49 +72 34 06.7 NGC 3516 = UGC 6153
-------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 28 186 Optical fluxes
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See also:
J/ApJ/806/129 : Space telescope RM project. II. Swift data (Edelson+, 2015)
J/A+A/563/A57 : Long-term variability of AGN at hard X-rays (Soldi+, 2014)
J/ApJ/755/60 : Reverberation mapping for 5 Seyfert 1 galaxies (Grier+, 2012)
J/ApJ/753/L2 : Reverberation mapping of AGNs (Assef+, 2012)
J/ApJ/739/57 : Ultra hard X-ray AGNs in the Swift/BAT survey (Koss+, 2011)
J/ApJ/713/L11 : X-ray properties of Seyfert 1 galaxies (Zhou+, 2010)
J/MNRAS/407/2399 : AGN activity and black hole mass (McKernan+, 2010)
J/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)
J/ApJ/622/129 : Lag-luminosity relationship in AGN (Sergeev+, 2005)
J/A+A/418/465 : Mid-infrared and hard X-ray emission in AGN (Lutz+, 2004)
J/ApJ/613/682 : AGN central masses & broad-line region sizes (Peterson+, 2004)
J/ApJS/95/1 : Atlas of Quasar Energy Distributions (Elvis+ 1994)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 d MJD [56316.5/56800.7] Modified Julian Date of
observation
12 A1 --- Obs Observatory code (1)
14- 15 A2 --- Filt Filter used ("B" (180 rows) or "g'" (6 rows))
17- 22 F6.3 mJy Flux [-0.3/1.3] Flux difference in Filt (2)
24- 28 F5.3 mJy e_Flux [0.003/0.3] Error in Flux
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Note (1): Observatory code as follows:
P = Multi-Spectral Imager (MSI) at the Pirka telescope
(B, V observing bands; 86 obs.);
M = Multicolor Imaging Telescopes for Survey and Monstrous Explosions
(MITSuME; g', Rc, Ic observing bands; 6 observations);
K = Kiso Wide Field Camera (KWFC) at the Kiso Schmidt telescope
(B, V observing bands; 32 obs.);
N = Multiband Imager for Nayuta Telescope (MINT) at the Nayuta telescope
(B, V observing bands; 31 obs.);
H = Hiroshima One-shot Wide-field Polarimeter (HOWPol) at the Kanata
telescope (B, V observing bands; 31 obs.).
See section 2.2 for further details.
Note (2): The flux difference with respect to the reference image
on 2014 April 08 (UTC); see section 3.2 for further explanations.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Dec-2016