We present the results of near-infrared (NIR) H-and K-band European Southern Observatory SINFONI integral field spectroscopy (IFS) of the Seyfert galaxy NGC 1566. We investigate the central kpc of this nearby galaxy, concentrating on excitation conditions, morphology, and stellar content. NGC 1566 was selected from our NUGA (-south) sample and is a ringed, spiral galaxy with a stellar bar in north-south direction (PA ∼ 5• ). The galaxy inhibits a very active Seyfert 1 nucleus but narrow line ratios from optical observations in the nuclear region are similar to Seyfert 2 galaxies. The recent strong activity phase, as inferred from strong variablity in X-ray to IR wavelengths, makes NGC 1566 an ideal candidate to look for feeding and feedback of a supermassive black hole. We present emission and absorption line measurements in the central kpc of NGC 1566. Broad and narrow Brγ lines were detected. The detection of a broad Brγ component is a clear sign of a supermassive black hole in the center. Blackbody emission temperatures of ∼1000 K are indicative of a hot dust component, the torus, in the nuclear region. The molecular hydrogen lines, hydrogen recombination lines, and [Fe ] indicate that the excitation at the center is coming from an AGN. The central region is predominantly inhabited by molecular gas, dust, and an old K-M type giant stellar population. The molecular gas and stellar velocity maps both show a rotation pattern. The molecular gas velocity field shows a perturbation toward the center that is typical for bars or spiral density waves. The molecular gas species of warm H 2 (1−0)S(1) and cold 12 CO(3−2) gas trace a nuclear gas disk of about 3 in radius with a nuclear spiral reaching toward the nucleus. From the equivalent width of H 2 (1−0)S(1) a molecular ring with r 3 can be inferred. This spiral seems to be an instrument that allows gas to fall toward the nucleus down to <50 pc scales. The excitation of molecular hydrogen in the nuclear gas disk is not clear, but diagnostic diagrams show a distinction between the nuclear region and a <9 Myr old star-forming region at the southwestern spiral arm. Gas that might be shocked is detected ≈2 from the center, which is visible in dispersion maps of H 2 (1−0)S(1) and 12 CO(3−2) and in the 0.87 mm continuum.
Circumnuclear star formation and active galactic nucleus (AGN) feedback is believed to play a critical role in galaxy evolution. The low-luminosity quasi-stellar object (LLQSO) sample that contains 99 of the closest AGN with redshift z ≤ 0.06 fills the gap between the local AGN population and high-redshift QSOs that is essential to understand the AGN evolution with redshift. In this paper, we present the results of the near-infrared H-and K-integral field spectroscopy of the inner kiloparsecs of the LLQSO HE 1029-1831 with SINFONI. Line maps show that ionized hydrogen gas is located in spiral arms within the stellar bar and in a circumnuclear ring. Line fluxes and diagnostic line ratios indicate recent or ongoing star formation in the circumnuclear region and the presence of young and intermediate-age stellar populations in the bulge. In particular, we find traces of an intense starburst in the circumnuclear region that has begun around 100 Myr ago but has declined to a fraction of the maximum intensity now. We estimate the dynamical bulge mass and find that the galaxy follows published M BH −M bulge relations. However, bulge-disk decomposition of the K-band image with B reveals that HE 1029-1831 does not follow the M BH −L bulge relations of inactive galaxies. We conclude that the deviation from M BH −L bulge relations of inactive galaxies in this source is instead caused by young stellar populations and not by an undermassive black hole.
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