12 papers · 1 filter
A Note on Hydrodynamic Viscosity and Selfgravitation in Accretion Disks
Wolfgang J. Duschl, Peter A. Strittmatter, Peter L. Biermann
We propose a generalized accretion disk viscosity prescription based on hydrodynamically driven turbulence at the critical effective Reynolds number. This approach is consistent wi…
The nature of strings in the nebula around Eta Carinae
Kerstin Weis, Wolfgang J. Duschl, You-Hua Chu
Eta Carinae is one of the most extreme cases of a Luminous Blue Variable star. A bipolar nebula of 17" size surrounds the central object. Even further out, a large amount of filame…
Diffraction-limited 76 mas Speckle Masking Observations of the Core of NGC 1068 with the SAO 6m Telescope
M. Wittkowski, Y. Balega, T. Beckert +3
We present the first K-band bispectrum speckle interferometry of NGC 1068 with an angular resolution of 76 mas (~5.5pc). This angular resolution allows us to attribute the measured…
Synchrotron radiation from quasi-monoenergetic electrons - Modelling the spectrum of Sgr A*
T. Beckert, W. J. Duschl
We investigate the spectrum of a quasi-monoenergetic ensemble of relativistic electrons, especially for the mildly relativistic case, and discuss the effect of inclination of the m…
Two Ring Nebulae around Blue Supergiants in the Large Magellanic Cloud
K. Weis, Y. -H. Chu, W. J. Duschl +1
Ring nebulae are often found around massive stars such as Wolf-Rayet stars, OB and Of stars and Luminous Blue Variables (LBVs). In this paper we report on two ring nebulae around b…
The bipolar structure of the LBV nebula around HR Carinae
K. Weis, W. J. Duschl, D. J. Bomans +2
HR Carinae is one of the few Luminous Blue Variables (LBVs) in the Galaxy. It has a nebula that appears bipolar. We have obtained imaging and high-dispersion, long-slit echelle dat…