TY - JOUR
T1 - A strong-lens survey in AEGIS
T2 - The influence of large-scale structure
AU - Moustakas, Leonidas A.
AU - Marshall, Phil
AU - Newman, Jeffrey A.
AU - Coil, Alison L.
AU - Cooper, Michael C.
AU - Davis, Marc
AU - Fassnacht, Christopher D.
AU - Guhathakurta, Puragra
AU - Hopkins, Andrew
AU - Koekemoer, Anton
AU - Konidaris, Nicholas P.
AU - Lotz, Jennifer M.
AU - Willmer, Christopher N.A.
PY - 2007/5/1
Y1 - 2007/5/1
N2 - We report on a visual search for galaxy-scale strong gravitational lenses over 650 arcmin2 of HST ACS (V606 and I814) imaging in the DEEP2 Extended Groth Strip. This field has Keck DEIMOS spectroscopy of ∼ 14,000 galaxies (∼ 75% complete to RAB < 24.1). We identify three strong galaxy-galaxy lenses: HST J141735+522646 is a previously known four-image lens (the "Cross"; zl, = 0.8106, zs = 3.40); HST J141820+523611 (the "Dewdrop"; zl = 0.5798, zs = 0.9818) features two pairs of arcs; and HST J141833+524352 (the "Anchor"; zl = 0.4625, no z s,) has one pair of arcs. Based on a normalized local density (1 + δ3), lenses are found to be in both under- and overdense local environments. All three lenses are fit well by singular isothermal ellipsoid models including external shear, with Xv2 ∼ 1. The model shears are ∼ 10%. Approximating all line-of-sight galaxies as singular isothermal sphere halos truncated at 200 h-1 kpc, with masses estimated through the Faber-Jackson relation, infers shears of ∼ 2%, much smaller than those required by the models. Therefore, the corresponding convergence estimates must also be suspect. If more realistic treatment of galaxies (and the large-scale structure that they are embedded in) were to match the inferred shears to the model shears, then the true convergence could be measured and the mass-sheet degeneracy broken.
AB - We report on a visual search for galaxy-scale strong gravitational lenses over 650 arcmin2 of HST ACS (V606 and I814) imaging in the DEEP2 Extended Groth Strip. This field has Keck DEIMOS spectroscopy of ∼ 14,000 galaxies (∼ 75% complete to RAB < 24.1). We identify three strong galaxy-galaxy lenses: HST J141735+522646 is a previously known four-image lens (the "Cross"; zl, = 0.8106, zs = 3.40); HST J141820+523611 (the "Dewdrop"; zl = 0.5798, zs = 0.9818) features two pairs of arcs; and HST J141833+524352 (the "Anchor"; zl = 0.4625, no z s,) has one pair of arcs. Based on a normalized local density (1 + δ3), lenses are found to be in both under- and overdense local environments. All three lenses are fit well by singular isothermal ellipsoid models including external shear, with Xv2 ∼ 1. The model shears are ∼ 10%. Approximating all line-of-sight galaxies as singular isothermal sphere halos truncated at 200 h-1 kpc, with masses estimated through the Faber-Jackson relation, infers shears of ∼ 2%, much smaller than those required by the models. Therefore, the corresponding convergence estimates must also be suspect. If more realistic treatment of galaxies (and the large-scale structure that they are embedded in) were to match the inferred shears to the model shears, then the true convergence could be measured and the mass-sheet degeneracy broken.
KW - Galaxies: high-redshift
KW - Gravitational lensing
KW - Large-scale structure of universe
UR - https://www.scopus.com/pages/publications/34249056521
UR - https://www.scopus.com/pages/publications/34249056521#tab=citedBy
U2 - 10.1086/517930
DO - 10.1086/517930
M3 - Article
AN - SCOPUS:34249056521
SN - 0004-637X
VL - 660
SP - L31-L34
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 II
ER -