scholarly journals Erratum: Hydrogen recombination near-infrared line mapping of Centaurus A with IRSF/SIRIUS

2020 ◽  
Vol 72 (5) ◽  
Author(s):  
Risako Katayama ◽  
Hidehiro Kaneda ◽  
Takuma Kokusho ◽  
Kumiko Morihana ◽  
Toyoaki Suzuki ◽  
...  
Keyword(s):  
Near Infrared ◽  
Hydrogen Recombination ◽  
Centaurus A

scholarly journals Near-infrared observations of star formation and gas flows in the NUGA galaxy NGC 1365

2019 ◽  
Vol 622 ◽  
pp. A128 ◽  
Author(s):  
Nastaran Fazeli ◽  
Gerold Busch ◽  
Mónica Valencia-S. ◽  
Andreas Eckart ◽  
Michal Zajaček ◽  
...  
Keyword(s):  
Star Formation ◽  
Emission Line ◽  
Galaxy Evolution ◽  
Large Scale ◽  
Near Infrared ◽  
Molecular Gas ◽  
Nuclear Region ◽  
Stellar Kinematics ◽  
Hydrogen Recombination ◽  
Ngc 1365

In the framework of understanding the gas and stellar kinematics and their relations to AGNs and galaxy evolution scenarios, we present spatially resolved distributions and kinematics of the stars and gas in the central ∼800 pc radius of the nearby Seyfert galaxy NGC 1365. We obtained H + K- and K-band near-infrared (NIR) integral-field observations from VLT/SINFONI. Our results reveal strong broad and narrow emission-line components of ionized gas (hydrogen recombination lines Paα and Brγ) in the nuclear region, as well as hot dust with a temperature of ∼1300 K, both typical for type-1 AGNs. From MBH − σ* and the broad components of hydrogen recombination lines, we find a black-hole mass of (5 − 10)×106 M⊙. In the central ∼800 pc, we find a hot molecular gas mass of ∼615 M⊙, which corresponds to a cold molecular gas reservoir of (2 − 8)×108 M⊙. However, there is a molecular gas deficiency in the nuclear region. The gas and stellar-velocity maps both show rotation patterns consistent with the large-scale rotation of the galaxy. However, the gaseous and stellar kinematics show deviations from pure disk rotation, which suggest streaming motions in the central < 200 pc and a velocity twist at the location of the ring which indicates deviations in disk and ring rotation velocities in accordance with published CO kinematics. We detect a blueshifted emission line split in Paα, associated with the nuclear region only. We investigate the star-formation properties of the hot spots in the circumnuclear ring which have starburst ages of ≲10 Myr and find indications for an age gradient on the western side of the ring. In addition, our high-resolution data reveal further substructure within this ring which also shows enhanced star forming activity close to the nucleus.

scholarly journals Hydrogen recombination near-infrared line mapping of Centaurus A with IRSF/SIRIUS

2020 ◽  
Vol 72 (5) ◽  
Author(s):  
Risako Katayama ◽  
Hidehiro Kaneda ◽  
Takuma Kokusho ◽  
Kumiko Morihana ◽  
Toyoaki Suzuki ◽  
...  
Keyword(s):  
Star Formation ◽  
Near Infrared ◽  
Galactic Halo ◽  
Dust Size Distribution ◽  
Upper Limit ◽  
Narrow Band Filter ◽  
Hα Emission ◽  
Southwest Region ◽  
H Ii Region ◽  
Centaurus A

Abstract Centaurus A (Cen A) is one of the most famous galaxies hosting an active galactic nucleus (AGN), where the interaction between AGN activities and surrounding interstellar and intergalactic media has been investigated. Recent studies reported detections of Hα emission from clouds in the galactic halo toward the northeast and southwest of the nucleus of Cen A, suggesting that AGN jets may have triggered star formation there. We performed near-infrared line mapping of Cen A with the IRSF 1.4 m telescope, using the narrow-band filter tuned for Paβ, from which we find that Paβ emission is not detected significantly from either of the northeast or southwest regions. The upper limit of the Paβ/Hα ratio in the northeast region is compatible with that expected for a typical H ii region, in line with the scenario that AGNs have triggered star formation there. On the other hand, the upper limit of Paβ/Hα in the southwest region is significantly lower than that expected for a typical H ii region. A possible explanation of the low Paβ/Hα ratio in the southwest region is the scattering of Hα and Paβ photons from the center of Cen A by dust grains in the halo clouds. From the upper limit of Paβ/Hα in the southwest region, we obtain constraints on the dust size distribution, which is found to be compatible with those seen in the interstellar medium of our Galaxy.

Gemini Near Infrared Spectrograph Observations of the Central Supermassive Black Hole in Centaurus A

2005 ◽  
Vol 130 (2) ◽  
pp. 406-417 ◽  
Author(s):  
Julia D. Silge ◽  
Karl Gebhardt ◽  
Marcel Bergmann ◽  
Douglas Richstone
Keyword(s):  
Black Hole ◽  
Near Infrared ◽  
Supermassive Black Hole ◽  
Centaurus A

The warped disk of Centaurus A in the near-infrared

1993 ◽  
Vol 412 ◽  
pp. 550 ◽  
Author(s):  
A. C. Quillen ◽  
James R. Graham ◽  
Jay A. Frogel
Keyword(s):  
Near Infrared ◽  
Centaurus A

scholarly journals The Discovery of Blazar-Type Nuclei in Two Nearby Radio Ellipticals

1987 ◽  
Vol 127 ◽  
pp. 427-428
Author(s):  
W B Sparks ◽  
J. Bailey ◽  
J C Hough ◽  
C. Brindle ◽  
D J Axon
Keyword(s):  
Synchrotron Radiation ◽  
Near Infrared ◽  
Position Angle ◽  
Elliptical Galaxies ◽  
Polarized Emission ◽  
Centaurus A

Near infrared polarimetry of Centaurus A and IC5063 has revealed the existence of a steep spectrum highly polarized source in the nuclei of both galaxies. The position angle of polarization is perpendicular to the radio position angle. We interpret this polarized emission as synchrotron radiation. This, together with a luminosity of 5 × 1041erg s-1, suggests the galaxies are low luminosity blazars and that such nuclei may be common in elliptical galaxies.

scholarly journals Optical and Near–Infrared Spectroscopy of the Emission Line Young Stellar Object Gy 2-18 (HHL 31)

2000 ◽  
Vol 175 ◽  
pp. 498-501 ◽  
Author(s):  
Paolo Persi ◽  
Vito Francesco Polcaro ◽  
Joaquin Bohigas ◽  
Mauricio Tapia
Keyword(s):  
Stellar Wind ◽  
Near Infrared ◽  
Young Star ◽  
Emission Lines ◽  
Line Intensities ◽  
Near Ir ◽  
Hydrogen Recombination ◽  
Recombination Emission ◽  
Measured Line ◽  
Extended Reflection

AbstractWe present the results of optical and near–IR spectroscopy of the massive young star associated with the extended reflection nebula Gy 2-18 (HHL31). The optical spectrum between 4000-5000 Å suggests a B0-B2 classification for this object. In addition the Hα line profile indicate the presence of a consistent stellar wind with a velocity of the order of 1200 km/s. The near-IR spectrum is dominated by the presence of the hydrogen recombination emission lines (Pfund and Bracket series). The measured line intensities of these lines are in agreement with the presence of a strong stellar wind in Gy2-18.

Near-infrared Imaging and Spectroscopy of Centaurus A

1992 ◽  
Vol 10 (2) ◽  
pp. 104-106 ◽  
Author(s):  
Vikki Meadows ◽  
David Allen
Keyword(s):  
Near Infrared ◽  
Infrared Imaging ◽  
Radio Galaxy ◽  
Infrared Images ◽  
Near Infrared Imaging ◽  
The Core ◽  
Imaging And Spectroscopy ◽  
Extended Emission ◽  
Centaurus A

AbstractWe present near-infrared images and spectra of the peculiar radio galaxy Centaurus A. The images reveal extended emission regions at the longer wavelengths and show colours characteristic of reddened starlight. We believe we are seeing stars within the warped disc of Cen A, which are obscured in the optical by dust. Both images and spectra indicate the presence of a compact core, whose colours are much redder than those of the surrounding stars. In the spectrum of the core, detections have been made of [Fe II] 1.644 μm, H2 2.122 μm and Br γ. These lines appear to peak on the nucleus and their presence and width suggest starburst activity.

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

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