TY - JOUR
T1 - A Deeply Buried Narrow-line Seyfert 1 Nucleus Uncovered in Scattered Light
AU - Pan, Xiang
AU - Lu, Honglin
AU - Komossa, S.
AU - Xu, Dawei
AU - Yuan, Weimin
AU - Sun, Luming
AU - Smith, Paul S.
AU - Zhang, Shaohua
AU - Jiang, Peng
AU - Yang, Chenwei
AU - Liu, Wenjuan
AU - Jiang, Ning
AU - Rashed, Y. E.
AU - Eckart, A.
AU - Dierkes, Jens
AU - Zhou, Hongyan
N1 - Publisher Copyright:
© 2019. The American Astronomical Society. All rights reserved.
PY - 2019/1/10
Y1 - 2019/1/10
N2 - We present spectropolarimetric and spectrophotometric observations of the peculiar active galactic nucleus (AGN) SDSS J120300.19+162443.7 (hereafter J1203+1624) at z = 0.1656. Its optical total flux spectra clearly show broad emission lines (BELs) in Hα and Hβ. After removal of narrow emission lines (NELs), the full width at half maximum (FWHM) of the Lorentzian BEL is ≈ 1270, fulfilling the conventional definition of a narrow-line Seyfert 1 (NLS1) galaxy. However, its NELs are unprecedentedly strong when compared to type 1 AGNs. This, together with its large MIR excess (g W4 = 13.172 mag), implies that the observer and the NEL region might see a different ionization continuum. Our optical spectropolarimetry confirms its type 2 nature by detecting a polarized blue continuum and Balmer BELs (FWHMPolarized BEL ≈ 1183 km s-1), with a high polarization degree of >20% in the blue wing. The mass and Eddington rate of the central black hole are estimated based on both transmitted and scattered AGN radiation, which is M. < 2.9 × 107 M⊙ and Lbol/LEdd > 5. Severe extinction of the AGN emission also enables a clear view of the compact host galaxy. The discovery of J1203+1624 suggests that NLS1 follows the AGN unification scheme, and studying its analogs could blaze a new trail for exploring the connection between black hole growth and star formation in the host galaxy. The interesting features of J1203+1624, like the peculiar NELs and inflowing scattering clouds within the sublimation radius, are worth detailed follow-ups in the future.
AB - We present spectropolarimetric and spectrophotometric observations of the peculiar active galactic nucleus (AGN) SDSS J120300.19+162443.7 (hereafter J1203+1624) at z = 0.1656. Its optical total flux spectra clearly show broad emission lines (BELs) in Hα and Hβ. After removal of narrow emission lines (NELs), the full width at half maximum (FWHM) of the Lorentzian BEL is ≈ 1270, fulfilling the conventional definition of a narrow-line Seyfert 1 (NLS1) galaxy. However, its NELs are unprecedentedly strong when compared to type 1 AGNs. This, together with its large MIR excess (g W4 = 13.172 mag), implies that the observer and the NEL region might see a different ionization continuum. Our optical spectropolarimetry confirms its type 2 nature by detecting a polarized blue continuum and Balmer BELs (FWHMPolarized BEL ≈ 1183 km s-1), with a high polarization degree of >20% in the blue wing. The mass and Eddington rate of the central black hole are estimated based on both transmitted and scattered AGN radiation, which is M. < 2.9 × 107 M⊙ and Lbol/LEdd > 5. Severe extinction of the AGN emission also enables a clear view of the compact host galaxy. The discovery of J1203+1624 suggests that NLS1 follows the AGN unification scheme, and studying its analogs could blaze a new trail for exploring the connection between black hole growth and star formation in the host galaxy. The interesting features of J1203+1624, like the peculiar NELs and inflowing scattering clouds within the sublimation radius, are worth detailed follow-ups in the future.
KW - galaxies: Seyfert
KW - quasars: emission lines
KW - quasars: individual (SDSS J120300.19+162443.7)
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U2 - 10.3847/1538-4357/aaf1bc
DO - 10.3847/1538-4357/aaf1bc
M3 - Article
AN - SCOPUS:85060185819
SN - 0004-637X
VL - 870
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 75
ER -