TY - JOUR
T1 - Direct observation of cosmic strings via their strong gravitational lensing effect - I. Predictions for high-resolution imaging surveys
AU - Gasparini, M. Alice
AU - Marshall, Phil
AU - Treu, Tommaso
AU - Morganson, Eric
AU - Dubath, Florian
PY - 2008/4
Y1 - 2008/4
N2 - 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 Gμ/c2 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 Gμ/c2 ∼ 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 Gμ/c2 ∼ 10-8. These limits will not be improved significantly by increasing the solid angle of the survey.
AB - 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 Gμ/c2 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 Gμ/c2 ∼ 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 Gμ/c2 ∼ 10-8. These limits will not be improved significantly by increasing the solid angle of the survey.
KW - Cosmology: observations
KW - Gravitational lensing
KW - Surveys
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U2 - 10.1111/j.1365-2966.2007.12657.x
DO - 10.1111/j.1365-2966.2007.12657.x
M3 - Article
AN - SCOPUS:41849133162
SN - 0035-8711
VL - 385
SP - 1959
EP - 1964
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 4
ER -