TY - JOUR
T1 - Broad-line region geometry from multiple emission lines in a single-epoch spectrum
AU - Kuhn, L.
AU - Shangguan, J.
AU - Davies, R.
AU - Man, A. W.S.
AU - Cao, Y.
AU - Dexter, J.
AU - Eisenhauer, F.
AU - Schreiber, N. M.Förster
AU - Feuchtgruber, H.
AU - Genzel, R.
AU - Gillessen, S.
AU - Hönig, S.
AU - Lutz, D.
AU - Netzer, H.
AU - Ott, T.
AU - Rabien, S.
AU - Santos, D. J.D.
AU - Shimizu, T.
AU - Sturm, E.
AU - Tacconi, L. J.
N1 - Publisher Copyright:
© The Authors 2024.
PY - 2024/4/1
Y1 - 2024/4/1
N2 - The broad-line region (BLR) of active galactic nuclei (AGNs) traces gas close to the central supermassive black hole (BH). Recent reverberation mapping (RM) and interferometric spectro-astrometry data have enabled detailed investigations of the BLR structure and dynamics as well as estimates of the BH mass. These exciting developments have motivated comparative investigations of BLR structures using different broad emission lines. In this work, we have developed a method to simultaneously model multiple broad lines of the BLR from a single-epoch spectrum. We applied this method to the five strongest broad emission lines (Hα, Hβ, Hγ, Paβ, and He i λ5876) in the UV-to-near-IR spectrum of NGC 3783, a nearby Type I AGN that has been well studied by RM and interferometric observations. Fixing the BH mass to the published value, we fit these line profiles simultaneously to constrain the BLR structure. We find that the differences between line profiles can be explained almost entirely as being due to different radial distributions of the line emission. We find that using multiple lines in this way also enables one to measure some important physical parameters, such as the inclination angle and virial factor of the BLR. The ratios of the derived BLR time lags are consistent with the expectation of theoretical model calculations and RM measurements.
AB - The broad-line region (BLR) of active galactic nuclei (AGNs) traces gas close to the central supermassive black hole (BH). Recent reverberation mapping (RM) and interferometric spectro-astrometry data have enabled detailed investigations of the BLR structure and dynamics as well as estimates of the BH mass. These exciting developments have motivated comparative investigations of BLR structures using different broad emission lines. In this work, we have developed a method to simultaneously model multiple broad lines of the BLR from a single-epoch spectrum. We applied this method to the five strongest broad emission lines (Hα, Hβ, Hγ, Paβ, and He i λ5876) in the UV-to-near-IR spectrum of NGC 3783, a nearby Type I AGN that has been well studied by RM and interferometric observations. Fixing the BH mass to the published value, we fit these line profiles simultaneously to constrain the BLR structure. We find that the differences between line profiles can be explained almost entirely as being due to different radial distributions of the line emission. We find that using multiple lines in this way also enables one to measure some important physical parameters, such as the inclination angle and virial factor of the BLR. The ratios of the derived BLR time lags are consistent with the expectation of theoretical model calculations and RM measurements.
KW - galaxies: Seyfert
KW - galaxies: active
KW - galaxies: individual: NGC 3783
KW - quasars: emission lines
KW - quasars: supermassive black holes
UR - http://www.scopus.com/inward/record.url?scp=85189487900&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/202348138
DO - 10.1051/0004-6361/202348138
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AN - SCOPUS:85189487900
SN - 0004-6361
VL - 684
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A52
ER -