Is every strong lens model unhappy in its own way? Uniform modelling of a sample of 13 quadruply+ imaged quasars

Shajib, AJ; Birrer, S; Treu, T; Auger, MW; Agnello, A; Anguita, T; Buckley-Geer, EJ; Chan, JHH; Collett, TE; Courbin, F; Fassnacht, CD; Frieman, J; Kayo, I; Lemon, C; Lin, H; Marshall, PJ; McMahon, R; More, A; Morgan, ND; Motta, V; Oguri, M; Ostrovski, F; Rusu, CE; Schechter, PL; Shanks, T; Suyu, SH; Meylan, G; Abbott, TMC; Allam, S; Annis, J; Avila, S; Bertin, E; Brooks, D; Carnero Rosell, A; Carrasco Kind, M; Carretero, J; Cunha, CE; da Costa, LN; De Vicente, J; Desai, S; Doel, P; Flaugher, B; Fosalba, P; García-Bellido, J; Gerdes, DW; Gruen, D; Gruendl, RA; Gutierrez, G; Hartley, WG; Hollowood, DL; Hoyle, B; James, DJ; Kuehn, K; Kuropatkin, N; Lahav, O; Lima, M; Maia, MAG; March, M; Marshall, JL; Melchior, P; Menanteau, F; Miquel, R; Plazas, AA; Sanchez, E; Scarpine, V; Sevilla-Noarbe, I; Smith, M; Soares-Santos, M; Sobreira, F; Suchyta, E; Swanson, MEC; Tarle, G; Walker, AR

Abstract

Strong-gravitational lens systems with quadruply imaged quasars (quads) are unique probes to address several fundamental problems in cosmology and astrophysics. Although they are intrinsically very rare, ongoing and planned wide-field deep-sky surveys are set to discover thousands of such systems in the next decade. It is thus paramount to devise a general framework to model strong-lens systems to cope with this large influx without being limited by expert investigator time. We propose such a general modelling framework (implemented with the publicly available software LENSTRONOMY) and apply it to uniformly model three-band Hubble Space Telescope Wide Field Camera 3 images of 13 quads. This is the largest uniformly modelled sample of quads to date and paves the way for a variety of studies. To illustrate the scientific content of the sample, we investigate the alignment between the mass and light distribution in the deflectors. The position angles of these distributions are well-aligned, except when there is strong external shear. However, we find no correlation between the ellipticity of the light and mass distributions. We also show that the observed flux-ratios between the images depart significantly from the predictions of simple smooth models. The departures are strongest in the bluest band, consistent with microlensing being the dominant cause in addition to millilensing. Future papers will exploit this rich data set in combination with ground-based spectroscopy and time delays to determine quantities such as the Hubble constant, the free streaming length of dark matter, and the normalization of the initial stellar mass function.

Citation

Shajib, A., Birrer, S., Treu, T., Auger, M., Agnello, A., Anguita, T., Buckley-Geer, E., Chan, J., Collett, T., Courbin, F., Fassnacht, C., Frieman, J., Kayo, I., Lemon, C., Lin, H., Marshall, P., McMahon, R., More, A., Morgan, N., Motta, V., …Walker, A. (2019). Is every strong lens model unhappy in its own way? Uniform modelling of a sample of 13 quadruply+ imaged quasars. Monthly Notices of the Royal Astronomical Society, 483(4), 5649-5671. https://doi.org/10.1093/mnras/sty3397

• Journal Article Type: Article
• Acceptance Date: Dec 9, 2018
• Online Publication Date: Dec 17, 2018
• Publication Date: Mar 11, 2019
• Deposit Date: Mar 14, 2019
• Publicly Available Date: Mar 14, 2019
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Royal Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 483
• Issue: 4
• Pages: 5649-5671
• DOI: https://doi.org/10.1093/mnras/sty3397
• Public URL: https://durham-repository.worktribe.com/output/1301003