1998/10/12 by L. Wisotzki, Lutz Wisotzki, Wisotzki, Lutz +8
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomy and Astrophysical Research #Astrophysics (astro-ph) #FOS: Physical sciences #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9810181
4 pages, 4 figures, accepted for A&A, Letters to the editor
arxiv created 1998/10/12 · openalex publication_date 1998/10/12 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present first results from five years of spectrophotometric monitoring of the bright double QSO and gravitational lens HE 1104-1805. The quasar has varied considerably over this time, while the emission line fluxes appear to have remained constant. We have constructed monochromatic continuum light curves for components A and B, finding that B leads the variability. A quantitative analysis with the Pelt method gives a best estimate for the light travel time delay of about 0.73 years, although a value as low as 0.3 cannot yet be excluded. We discuss possible models for the QSO-lens configuration and use our measured time delay to predict the redshift of the lens, zd. Finding that most likely zd < 1, we can rule out the hitherto favoured values of zd = 1.32 or 1.66. A new candidate is an absorption system at z=0.73, but the lens could also be an elliptical not detected in absorption.