Mid-infrared view of cool evolved stars with the Very Large Telescope Interferometer

2008 ◽  
Author(s):  
Keiichi Ohnaka ◽  
Thomas Driebe ◽  
Karl-Heinz Hofmann ◽  
Gerd Weigelt ◽  
Markus Wittkowski
Keyword(s):  
Large Telescope ◽  
Mid Infrared ◽  
Evolved Stars ◽  
Very Large Telescope

Cool evolved stars as seen by the Very Large Telescope Interferometer: Power of infrared spectro-interferometry

2007 ◽  
Author(s):  
K. Ohnaka ◽  
T. Driebe ◽  
K.-H. Hofmann ◽  
D. Schertl ◽  
G. Weigelt ◽  
...  
Keyword(s):  
Large Telescope ◽  
Evolved Stars ◽  
Very Large Telescope

scholarly journals New evidence for the ubiquity of prominent polar dust emission in AGN on tens of parsec scales

2019 ◽  
Vol 489 (2) ◽  
pp. 2177-2188 ◽  
Author(s):  
D Asmus
Keyword(s):  
Active Galactic Nuclei ◽  
Dust Emission ◽  
Galactic Nuclei ◽  
Large Telescope ◽  
Mid Infrared ◽  
Bolometric Luminosity ◽  
Very Large Telescope ◽  
Lower Limits ◽  
New Evidence ◽  
Small Dispersion

ABSTRACT The key ingredient of active galactic nuclei (AGN) unification, the dusty obscuring torus was so far held responsible for the observed mid-infrared (MIR) emission of AGN. However, the best studied objects with Very Large Telescope Interferometer (VLTI)/MID-infrared Interferometric instrument (MIDI) show that instead a polar dusty wind is dominating these wavelengths, leaving little room for a torus contribution. But is this wind a ubiquitous part of the AGN? To test this, we conducted a straightforward detection experiment, using the upgraded Very Large Telescope (VLT)/VLT Imager and Spectrometer for mid-InfraRed (VISIR) for deep subarcsecond resolution MIR imaging of a sample of nine [O iv]-bright, obscured AGN, all of which were predicted to have detectable polar emission. Indeed, the new data reveal such emission in all objects but one. We further estimate lower limits on the extent of the polar dust and show that the polar dust emission is dominating the total MIR emission of the AGN. These findings support the scenario that polar dust is not only ubiquitous in AGN but also an integral part of its structure, processing a significant part of the primary radiation. The polar dust has to be optically thin on average, which explains e.g. the small dispersion in the observed MIR–X-ray luminosity correlation. At the same time, it has to be taken into account when deriving covering factors of obscuring material from MIR to bolometric luminosity ratios. Finally, we find a new tentative trend of increasing MIR emission size with increasing Eddington ratio.

Perspective of imaging in the mid-infrared at the Very Large Telescope Interferometer

2012 ◽  
Author(s):  
B. Lopez ◽  
S. Lagarde ◽  
P. Antonelli ◽  
W. Jaffe ◽  
R. Petrov ◽  
...  
Keyword(s):  
Large Telescope ◽  
Mid Infrared ◽  
Very Large Telescope

scholarly journals On the origin of [Ne II] emission in young stars: mid-infrared and optical observations with the Very Large Telescope

2012 ◽  
Vol 543 ◽  
pp. A30 ◽  
Author(s):  
C. Baldovin-Saavedra ◽  
M. Audard ◽  
A. Carmona ◽  
M. Güdel ◽  
K. Briggs ◽  
...  
Keyword(s):  
Young Stars ◽  
Optical Observations ◽  
Large Telescope ◽  
Mid Infrared ◽  
Very Large Telescope

scholarly journals Resolved Mid-Infrared Imaging of AGN: An Isotropic Measure of Intrinsic Power

2009 ◽  
Vol 5 (S267) ◽  
pp. 108-108
Author(s):  
P. Gandhi ◽  
H. Horst ◽  
A. Smette ◽  
S. F. Hönig ◽  
A. Comastri ◽  
...  
Keyword(s):  
Strong Correlation ◽  
Infrared Imaging ◽  
Large Telescope ◽  
Mid Infrared ◽  
X Ray ◽  
Isotropic Measure ◽  
Very Large Telescope

We present a strong correlation between 12μm mid-IR and intrinsic X-ray (2–10 keV) luminosities of local Seyferts. This work is based on new diffraction-limited mid-IR observations with the 8-m Very Large Telescope (VLT), resulting in the least-contaminated core fluxes of 42 Seyferts to date.

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