J/AJ/159/245 Xinglong optical spectra of UGC3223 in 4 epochs (Wang+, 2020)
Suspended and restored activities of a nearby supermassive black hole.
Wang J., Xu D.W., Sun S.S., Feng Q.C., Li T.R., Xiao P.F., Wei J.Y.
<Astron. J., 159, 245 (2020)>
=2020AJ....159..245W 2020AJ....159..245W
ADC_Keywords: Active gal. nuclei; Black holes; Galaxies, Seyfert;
Spectra, optical
Keywords: Active galactic nuclei ; Emission line galaxies
Abstract:
The discovery of spectral type transition of active galactic nuclei
(AGNs), the so-called "changing-look" (CL) phenomenon, challenges the
widely accepted AGN paradigm, not only in the orientation-based
unified model, but also in the standard disk model. In past decades,
only a couple of nearby repeat changing-look active galactic nuclei
(CL-AGNs) have been identified. Here we report spectroscopic
observations of UGC3223 over the course of 18yr, from 2001 onwards.
Combining the spectrum taken in 1987 by Stirpe, we have witnessed its
type transitions from 1.5 to 2.0 to 1.8 over 32yr, and captured a
long-lived (at least 10 yr) thorough "turn-off" state with a spectrum
typical of a Seyfert 2 galaxy. The long-term thorough turn-off state
probably suggests a once-dormant and an awakening central engine in
UGC3223. We argue that the (dis)appearance of the broad Balmer
emission lines can be explained by the disk-wind broad-line region
model given the evolution of the calculated Eddington ratio of
accretion of the supermassive black hole.
Description:
The long-slit spectra of UGC3223 have been taken by us using the 2.16m
telescope at the Xinglong observatory of National Astronomical
Observatories, Chinese Academy of Sciences (NAOC) in four epochs from
2001 to 2019. The observations were carried out with the Optomechanics
Research Inc. spectrograph equipped with a back-illuminated SPEC
1340x400CCD as the detector. A grating of 300grooves/mm and a slit of
2" oriented in the south-north direction were used in the
observations. This setup finally leads to a spectral resolution of
∼9Å as measured from the sky emission lines and comparison arcs.
The blazed wavelength was fixed at 6000Å in all the observation
runs, which provides a wavelength coverage from 3400 to 8600Å in
the observer frame.
Objects:
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RA (2000) DE Designation(s)
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04 59 09.40 +04 58 30.8 UGC3223 = LEDA 16482
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
fig1a.dat 30 1017 Xinglong spectrum of UGC3223 on 2001/11/16
fig1b.dat 30 981 Xinglong spectrum of UGC3223 on 2003/10/25
fig1c.dat 30 1200 Xinglong spectrum of UGC3223 on 2010/11/09
fig1d.dat 30 1901 Xinglong spectrum of UGC3223 on 2019/09/06
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See also:
III/116 : Spectrophotometric Standards (Massey+ 1988)
VII/248 : Quasars and Active Galactic Nuclei (12th Ed.) (Veron+ 2006)
J/ApJ/670/92 : New sample of low-mass black holes in AGN (Greene+, 2007)
J/A+A/545/A15 : AMIGA XI. Optical nuclear activity (Sabater+, 2012)
J/ApJ/755/167 : Low-mass black holes in SDSS Seyfert 1 galaxies (Dong+, 2012)
J/ApJ/792/30 : NEOWISE magnitudes for near-Earth objects (Mainzer+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/ApJ/794/75 : HST-COS UV spectra observations of AGNs (Stevans+, 2014)
J/ApJ/806/22 : SEAMBHs IV. Hβ time lags (Du+, 2015)
J/A+A/596/A64 : 4 AGN optical spectra (Simmonds+, 2016)
J/ApJS/226/11 : IR spectroscopy of AGN & starbursts (Samsonyan+, 2016)
J/ApJ/854/160 : SDSS & DES long-term extreme variability QSOs (Rumbaugh+, 2018)
J/ApJ/870/123 : Swift optical & UV flux of four AGNs (Edelson+, 2019)
Byte-by-byte Description of file: fig1[a-d].dat
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Bytes Format Units Label Explanations
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1- 16 F16.11 0.1nm lambda [3457/8587] Spectrum wavelength
18- 30 E13.6 cW/m2/nm flux Flux, erg/s/cm2/Angstroms
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 06-Jul-2020