DES meets Gaia: discovery of strongly lensed quasars from a multiplet search. Issue 4 (4th June 2018)

• Record Type: Journal Article
• Authors: Agnello, A; Lin, H; Kuropatkin, N; Buckley-Geer, E; Anguita, T; Schechter, P L; Morishita, T; Motta, V; Rojas, K; Treu, T; Amara, A; Auger, M W; Courbin, F; Fassnacht, C D; Frieman, J; More, A; Marshall, P J; McMahon, R G; Meylan, G; Suyu, S H; Glazebrook, K; Morgan, N; Nord, B; Abbott, T M C; Abdalla, F B; Annis, J; Bechtol, K; Benoit-Lévy, A; Bertin, E; Bernstein, R A; Brooks, D; Burke, D L; Rosell, A Carnero; Carretero, J; Cunha, C E; D'Andrea, C B; da Costa, L N; Desai, S; Drlica-Wagner, A; Eifler, T F; Flaugher, B; García-Bellido, J; Gaztanaga, E; Gerdes, D W; Gruen, D; Gruendl, R A; Gschwend, J; Gutierrez, G; Honscheid, K; James, D J; Kuehn, K; Lahav, O; Lima, M; Maia, M A G; March, M; Menanteau, F; Miquel, R; Ogando, R L C; Plazas, A A; Sanchez, E; Scarpine, V; Schindler, R; Schubnell, M; Sevilla-Noarbe, I; Smith, M; Soares-Santos, M; Sobreira, F; Suchyta, E; Swanson, M E C; Tarle, G; Tucker, D; Wechsler, R;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 479:Issue 4(2018)
• Page Start: 4345
• Page End: 4354
• Publication Date: 2018-06-04
• Subjects: gravitational lensing: strong -- methods: statistical -- techniques: image processing -- surveys; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/sty1419
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We report the discovery, spectroscopic confirmation, and first lens models of the first, strongly lensed quasars from a combined search in WISE and Gaia-DR1 over the DES footprint. Their Einstein radii span a range between ≈2.0 arcsec and ≈0.4 arcsec. Two of these (WGD2038-4008, RA = 20:38:02.65, Dec. = −40:08:14.64; WGD2021-4115, RA = 20:21:39.45, Dec. = −41:15:57.11) also have confirmed deflector redshifts. The four-image lens WGD2038-4008, with source and deflector redshifts s = 0.777 ± 0.001 and zl = 0.230 ± 0.002, respectively, has a deflector with radius R eff ≈ 3.4 arcsec, stellar mass $\log (M_{\star }/M_{\odot })=11.64^{+0.20}_{-0.43}$, and extended isophotal shape variation. Simple lens models yield Einstein radii R E = (1.30 ± 0.04) arcsec, axis ratio q = 0.75 ± 0.1 (compatible with that of the starlight) and considerable shear-ellipticity degeneracies. The two-image lens WGD2021-4115 has zs = 1.390 ± 0.001 and zl = 0.335 ± 0.002, and Einstein radius R E = (1.1 ± 0.1) arcsec, but higher-resolution imaging is needed to accurately separate the deflector and faint quasar image. Analogous lens model degeneracies hold for the other six lenses (J0146-1133, J0150-4041, J0235-2433, J0245-0556, J0259-2338, and J0508-2748) shown in this paper.