4 papers
The Equatorial Outflow of SS433
Z. Paragi, I. Fejes, R. C. Vermeulen +3
We present VLBI imaging results for SS433 from the period 1995-2000. An equatorial emission region is detected and confirmed in 7 experiments at 1.6 and 5 GHz. The structure of the…
Gravitational lensing statistics with extragalactic surveys. I. A lower limit on the cosmological constant
Ralf Quast, Phillip Helbig
We reanalyse optical gravitational lens surveys from the literature in order to determine relative probabilities in the - plane, using a softened singular isothermal…
Gravitational lensing statistics with extragalactic surveys. III. Joint constraints on lambda_0 and Omega_0 from lensing statistics and the m-z relation for type Ia supernovae
Phillip Helbig
I present constraints on cosmological parameters in the lambda_0-Omega_0 plane from a joint analysis of gravitational lensing statistics (astro-ph/9904175) and the magnitude-redshi…
Lensing galaxies: light or dark?
N. Jackson, P. Helbig, I. W. A. Browne +4
In a recent paper, Hawkins (1997) argues on the basis of statistical studies of double-image gravitational lenses and lens candidates that a large population of dark lenses exists…