Is QSO1146+111B,C due to lensing by a cosmic string?
Abstract
A predicted consequence of cosmic strings is that they should produce equal-brightness double-lens images of distant quasars (QSOs), with separations of up to several minutes of arc (see refs 1, 2). Here I discuss a newly discovered lens candidate3-6: QSO1146+111B,C which appears to consist of two images of equal brightness (B is 1.02 times as bright as C, with virtually identical spectra over the observed range) of a quasar at redshift z = 1.01, which are separated by 2.6 arc min. If this is produced by a cosmic string, its mass per unit length is µ>=4.0×1023 g cm-1, a value large enough to be interesting for string-assisted galaxy formation7-9 and near the upper limits implied by the isotropy of the cosmic microwave background2,10 and constraints on gravitational radiation11. But note that four other QSOs, also close enough to be double-imaged, have thus far not been detected. Searches for these and for the microwave background temperature shift across the string2,10 would be useful.
- Publication:
-
Nature
- Pub Date:
- May 1986
- DOI:
- 10.1038/321420a0
- Bibcode:
- 1986Natur.321..420G
- Keywords:
-
- Gravitational Lenses;
- Quasars;
- String Theory;
- Mass Distribution;
- Astrophysics