The first detection of the silicate absorption feature in AGNs was made at 9.7 micrometer for the prototypical Seyfert 2 galaxy NGC 1068 over 30 years ago, indicating the presence of a large column of silicate dust in the line-of-sight to the nucleus. It is now well recognized that type 2 AGNs exhibit prominent silicate absorption bands, while the silicate bands of type 1 AGNs appear in emission. More recently, using the Mid-Infrared Interferometric Instrument on the Very Large Telescope Interferometer, ...
Tópico(s): Galaxies: Formation, Evolution, Phenomena
2010 - Oxford University Press | Monthly Notices of the Royal Astronomical Society Letters
... of NGC 2346, NGC 6563, NGC 6826 and NGC 7009 in the Hα line (6562.8 å) were corrected for cosmic ray hits, background/foreground stars were removed, and the position angles PA of their symmetry axes were determined with a maximum correlation criterion. For NGC 6563, the axis was shifted manually to the ...
Tópico(s): Astronomy and Astrophysical Research
1997 - Cambridge University Press | Symposium - International Astronomical Union
A. K. Dupree, G. M. Harper, Lee Hartmann, Carole Jordan, A. W. Rodgers, Graeme H. Smith,
... stars, A31 and A59, in the globular cluster NGC 6752 exhibit Mg II (2800 A) emission with surface fluxes comparable to those observed among metal-deficient halo field giants, and among low-activity Population I giants. Optical echelle spectra of these cluster giants reveal emission in the core of the Ca II K (3933.7 A) line, and in the wing of the H-alpha (6562.8 A) profile. Asymmetries exist both in the ...
Tópico(s): Geological and Geophysical Studies
1990 - IOP Publishing | The Astrophysical Journal
Semir Smajić, L. Moser, A. Eckart, M. Valencia-S., F. Combes, M. Horrobin, S. García‐Burillo, M. García-Marín, Sebastian Fischer, J. Zuther,
We present the results of near-infrared (NIR) H- and K-band European Southern Observatory SINFONI integral field spectroscopy (IFS) of the Seyfert 2 galaxy NGC 1433. We present emission and absorption line measurements in the central kpc of NGC 1433. We detect a narrow Balmer line and several H2 lines. We find that the stellar continuum peaks in the optical and NIR in the same position, indicating that there is no covering of the center by a nuclear dust lane. A strong velocity gradient is detected ...
Tópico(s): Stellar, planetary, and galactic studies
2014 - EDP Sciences | Astronomy and Astrophysics