Magnification Bias Corrections to Galaxy-Lensing Cross-Correlations
| dc.creator | Ziour, R. | |
| dc.creator | Hui, L. | |
| dc.date | 2008-09-18 | |
| dc.date | 2009-05-05 | |
| dc.date.accessioned | 2026-07-07T13:11:09Z | |
| dc.date.available | 2026-07-07T13:11:09Z | |
| dc.description | Galaxy-galaxy or galaxy-quasar lensing can provide important information on the mass distribution in the Universe. It consists of correlating the lensing signal (either shear or magnification) of a background galaxy/quasar sample with the number density of a foreground galaxy sample. However, the foreground galaxy density is inevitably altered by the magnification bias due to the mass between the foreground and the observer, leading to a correction to the observed galaxy-lensing signal. The aim of this paper is to quantify this correction. The single most important determining factor is the foreground redshift z: the correction is small if the foreground galaxies are at low redshifts but can become non-negligible for sufficiently high redshifts. For instance, we find that for the multipole l=1000, the correction is above 1%*(5s-2)/b for z<0.37, and above 5%*(5s-2)/b for z<0.67, where s is the number count slope of the foreground sample, and b its galaxy bias. These considerations are particularly important for geometrical measures, such as the Jain and Taylor ratio or its generalization by Zhang et al. Assuming (5s-2)/b=1, we find that the foreground redshift should be limited to z<0.45 in order to avoid biasing the inferred dark energy equation of state w by more than 5%, and that even for a low foreground redshift (< 0.45), the background samples must be well separated from the foreground to avoid incurring a bias of similar magnitude. Lastly, we briefly comment on the possibility of obtaining these geometrical measures without using galaxy shapes, using instead magnification bias itself. | |
| dc.description | 10 pages, 7 figures; v2: minor revisions, as accepted for publication in Physical Review D | |
| dc.identifier | https://arxiv.org/abs/0809.3101 | |
| dc.identifier | http://arxiv.org/abs/0809.3101 | |
| dc.identifier | Phys.Rev.D78:123517,2008 | |
| dc.identifier | doi:10.1103/PhysRevD.78.123517 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/229199 | |
| dc.subject | Astrophysics | |
| dc.title | Magnification Bias Corrections to Galaxy-Lensing Cross-Correlations | |
| dc.type | text |