Time-delay quasars: scales and orders of magnitudes

Abstract

We can think of a lensed quasar as taking the Hubble time, shrinking it by \~10^{-11}, and then presenting the result to us as a time delay; the shrinking factor is of the order of fractional sky-area that the lens occupies. This cute fact is a straightforward consequence of lensing theory, and enables a simple rescaling of time delays. Observed time delays have a 40-fold range, but after rescaling the range reduces to 5-fold. The latter range depends on details of the lens and lensing configuration--for example, quads have systematically shorter rescaled time delays than doubles--and is as expected from a simple model. The hypothesis that observed time-delay lenses all come from a generalized-isothermal family can be ruled out. But there is no indication of drastically different populations either.

To appear in A&A

References in corpus (3)

• The time delay of the quadruple quasar RX J0911.4+0551
• Qualitative Theory for Lensed QSOs
• Is B1422+231 a Golden Lens?

Cited by in corpus (8)

• Gravitational Lens Time Delays: A Statistical Assessment of Lens Model Dependences and Implications for the Global Hubble Constant
• The Hubble time inferred from 10 time-delay lenses
• Gravitational lensing model degeneracies: Is steepness all-important?
• Models of the giant quadruple quasar SDSS J1004+4112
• Radial density profiles of time-delay lensing galaxies
• Discovering Gravitational Lenses Through Measurements Of Their Time Delays
• How accurate are the time delay estimates in gravitational lensing?
• COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses IV. Models of prospective time-delay lenses