Direct observation of cosmic strings via their strong gravitational lensing effect - I. Predictions for high-resolution imaging surveys

作者：Gasparini M Alice^*; Marshall Phil; Treu Tommaso; Morganson Eric; Dubath Florian

来源：Monthly Notices of the Royal Astronomical Society, 2008, 385(4): 1959-1964.

DOI：10.1111/j.1365-2966.2007.12657.x

• gravitational lensing
• surveys
• cosmology : observations

We use present theoretical estimates for the density of long cosmic strings to predict the number of strong gravitational lensing events in astronomical imaging surveys as a function of the angular resolution and survey area. We show that angular resolution is the single most important factor, and that interesting limits on the dimensionless string tension G mu/c(2) can be obtained by existing and planned surveys. At the resolution of the Hubble Space Telescope (HST) (0.14 arcsec), it is sufficient to survey of the order of a few square degrees - well within reach of the current HST archive - to probe the regime G mu/c(2) similar to 10(-7). If lensing by cosmic strings is not detected, such a survey would improve the limit on the string tension by a factor of two over that available from the cosmic microwave background. Future high resolution imaging surveys, covering a few hundred square degrees or more, either from space in the optical or from large-format radio telescopes on the ground, would be able to further lower this limit to G mu/c(2) similar to 10(-8). These limits will not be improved significantly by increasing the solid angle of the survey.

• 出版日期2008-4-21