The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs

Journal Article · Mon Mar 09 00:00:00 EDT 2020 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/staa652· OSTI ID:1638183

Lemon, C.  ^[1]; Auger, M. W. ^[2]; McMahon, R. ^[2]; Anguita, T.  ^[3]; Apostolovski, Y. ^[4]; Chen, G. C-F  ^[5]; Fassnacht, C. D. ^[5]; Melo, A. D. ^[6]; Motta, V. ^[6]; Shajib, A.  ^[7]; Treu, T. ^[7]; Agnello, A. ^[8]; Buckley-Geer, E. ^[9]; Schechter, P. L. ^[10]; Birrer, S. ^[11]; Collett, T.  ^[12]; Courbin, F. ^[13]; Rusu, C. E.  ^[14]; Abbott, T. M. C. ^[15]; Allam, S. ^[9] ; Annis, J. ^[9]; Avila, S.  ^[16]; Bertin, E. ^[17]; Brooks, D. ^[18]; Burke, D. L. ^[19]; Carnero Rosell, A.  ^[20]; Carrasco Kind, M.  ^[21]; Carretero, J. ^[22]; Costanzi, M. ^[23]; da Costa, L. N. ^[24]; De Vicente, J. ^[25]; Desai, S. ^[26]; Eifler, T. F. ^[27]; Flaugher, B. ^[9]; Frieman, J. ^[28]; García-Bellido, J. ^[16]; Gaztanaga, E.  ^[29]; Gerdes, D. W. ^[30]; Gruen, D.  ^[31]; Gruendl, R. A. ^[21]; Gschwend, J. ^[24]; Gutierrez, G. ^[9]; Honscheid, K. ^[32]; James, D. J. ^[33]; Kim, A.  ^[34]; Krause, E. ^[35]; Kuehn, K. ^[36]; Kuropatkin, N. ^[9]; Lahav, O. ^[18]; Lima, M. ^[37]; Lin, H. ^[9]; Maia, M. A. G. ^[24]; March, M.  ^[38]; Marshall, J. L. ^[39]; Menanteau, F. ^[21]; Miquel, R. ^[40]; Palmese, A.  ^[28]; Paz-Chinchón, F. ^[21]; Plazas, A. A.  ^[41]; Roodman, A. ^[19]; Sanchez, E. ^[25]; Schubnell, M. ^[42]; Serrano, S. ^[29]; Smith, M.  ^[43]; Soares-Santos, M.  ^[44]; Suchyta, E.  ^[45]; Tarle, G. ^[42]; Walker, A. R. ^[15]

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1. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK; Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK; Institute of Physics, Laboratoire d’Astrophysique, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, CH-1290 Versoix, Switzerland
2. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK; Kavli Institute for Cosmology, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
3. Departamento de Ciencias Fisicas, Universidad Andres Bello, Fernandez Concha 700, Las Condes, Santiago, Chile; Millennium Institute of Astrophysics, Monseñor Nuncio Sotero Sanz 100, Oficina 104, Providencia 7500011, Santiago, Chile
4. Departamento de Ciencias Fisicas, Universidad Andres Bello, Fernandez Concha 700, Las Condes, Santiago, Chile
5. Physics Department, UC Davis, 1 Shields Ave., Davis, CA 95616, USA
6. Instituto de Física y Astronomía, Universidad de Valparaíso, Avda. Gran Bretaña 1111, Playa Ancha, Valparaíso 2360102, Chile
7. Physics and Astronomy Department, University of California, Los Angeles, CA, 90095, USA
8. DARK, Niels Bohr Institute, University of Copenhagen, Lyngbyvej 2, DK-2100 Copenhagen, Denmark
9. Fermi National Accelerator Laboratory, PO Box 500, Batavia, IL 60510, USA
10. MIT Kavli Institute for Astrophysics and Space Research, Cambridge, MA 02139, USA
11. Physics and Astronomy Department, University of California, Los Angeles, CA, 90095, USA; Department of Physics, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA
12. Institute of Cosmology & Gravitation, University of Portsmouth, Portsmouth PO1 3FX, UK
13. Institute of Physics, Laboratoire d’Astrophysique, Ecole Polytechnique Fédérale de Lausanne (EPFL), Observatoire de Sauverny, CH-1290 Versoix, Switzerland
14. National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan; Subaru Telescope, National Astronomical Observatory of Japan, 650 N Aohoku Pl, Hilo, HI 96720, USA
15. Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatory, Casilla 603, La Serena, Chile
16. Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid, E-28049 Madrid, Spain
17. CNRS, UMR 7095, Institut d’Astrophysique de Paris, F-75014 Paris, France; Institut d’Astrophysique de Paris, Sorbonne Universités, UPMC Univ Paris 06, UMR 7095, F-75014 Paris, France
18. Department of Physics & Astronomy, University College London, Gower Street, London WC1E 6BT, UK
19. Department of Physics, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA; SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
20. Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain; Laboratório Interinstitucional de e-Astronomia – LIneA, Rua Gal. José Cristino 77, Rio de Janeiro, RJ 20921-400, Brazil
21. Department of Astronomy, University of Illinois at Urbana-Champaign, 1002 W. Green Street, Urbana, IL 61801, USA; National Center for Supercomputing Applications, 1205 West Clark St., Urbana, IL 61801, USA
22. Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, E-08193 Bellaterra (Barcelona), Spain
23. INAF – Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-34143 Trieste, Italy; Institute for Fundamental Physics of the Universe, Via Beirut 2, I-34014 Trieste, Italy
24. Laboratório Interinstitucional de e-Astronomia – LIneA, Rua Gal. José Cristino 77, Rio de Janeiro, RJ 20921-400, Brazil; Observatório Nacional, Rua Gal. José Cristino 77, Rio de Janeiro, RJ 20921-400, Brazil
25. Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
26. Department of Physics, IIT Hyderabad, Kandi, Telangana 502285, India
27. Department of Astronomy/Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA; Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91109, USA
28. Fermi National Accelerator Laboratory, PO Box 500, Batavia, IL 60510, USA; Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637, USA
29. Institut d’Estudis Espacials de Catalunya (IEEC), E-08034 Barcelona, Spain; Institute of Space Sciences (ICE, CSIC), Campus UAB, Carrer de Can Magrans, s/n, E-08193 Barcelona, Spain
30. Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA; Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA
31. Department of Physics, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA; SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA; Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305, USA
32. Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210, USA; Department of Physics, The Ohio State University, Columbus, OH 43210, USA
33. Center for Astrophysics | Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA
34. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
35. Department of Astronomy/Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065, USA
36. Australian Astronomical Optics, Macquarie University, North Ryde, NSW 2113, Australia; Lowell Observatory, 1400 Mars Hill Rd, Flagstaff, AZ 86001, USA
37. Laboratório Interinstitucional de e-Astronomia – LIneA, Rua Gal. José Cristino 77, Rio de Janeiro, RJ 20921-400, Brazil; Departamento de Física Matemática, Instituto de Física, Universidade de São Paulo, CP 66318, São Paulo, SP 05314-970, Brazil
38. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA
39. Department of Physics and Astronomy, George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A&M University, College Station, TX 77843, USA
40. Institut de Física d’Altes Energies (IFAE), The Barcelona Institute of Science and Technology, Campus UAB, E-08193 Bellaterra (Barcelona), Spain; Institució Catalana de Recerca i Estudis Avançats, E-08010 Barcelona, Spain
41. Department of Astrophysical Sciences, Princeton University, Peyton Hall, Princeton, NJ 08544, USA
42. Department of Physics, University of Michigan, Ann Arbor, MI 48109, USA
43. School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK
44. Physics Department, Brandeis University, 415 South Street, Waltham, MA 02453, USA
45. Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA

Here, we report the results of the STRong lensing Insights into the Dark Energy Survey (STRIDES) follow-up campaign of the late 2017/early 2018 season. We obtained spectra of 65 lensed quasar candidates with ESO Faint Object Spectrograph and Camera 2 on the NTT and Echellette Spectrograph and Imager on Keck, confirming 10 new lensed quasars and 10 quasar pairs. Eight lensed quasars are doubly imaged with source redshifts between 0.99 and 2.90, one is triply imaged (DESJ0345-2545, z = 1.68), and one is quadruply imaged (quad: DESJ0053-2012, z = 3.8). Singular isothermal ellipsoid models for the doubles, based on high-resolution imaging from SAMI on Southern Astrophysical Research Telescope or Near InfraRed Camera 2 on Keck, give total magnifications between 3.2 and 5.6, and Einstein radii between 0.49 and 1.97 arcsec. After spectroscopic follow-up, we extract multi-epoch grizY photometry of confirmed lensed quasars and contaminant quasar + star pairs from DES data using parametric multiband modelling, and compare variability in each system’s components. By measuring the reduced χ² associated with fitting all epochs to the same magnitude, we find a simple cut on the less variable component that retains all confirmed lensed quasars, while removing 94 per cent of contaminant systems. Based on our spectroscopic follow-up, this variability information improves selection of lensed quasars and quasar pairs from 34-45 per cent to 51–70 per cent, with most remaining contaminants being star-forming galaxies. Using mock lensed quasar light curves we demonstrate that selection based only on variability will over-represent the quad fraction by 10 per cent over a complete DES magnitude-limited sample, explained by the magnification bias and hence lower luminosity/more variable sources in quads.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Michigan, Ann Arbor, MI (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); USDOE Office of Science (SC), High Energy Physics (HEP); Swiss National Science Foundation (SNSF); European Research Council (ERC); National Science Foundation (NSF)
• Contributing Organization: STRIDES Collaboration
• Grant/Contract Number: SC0019193; AC02-76SF00515; AC05-00OR22725; AC02-05CH11231; AST-1138766; AST-1536171; AST-1715611; AST-1450141; AST-1906976; AYA2015-71825; ESP2015-66861; FPA2015-68048; SEV-2016-0588; SEV-2016-0597; MDM-2015-0509; 240672; 291329; 306478; 465376/2014-2; 787886; 16599; 6108-00470; 1190335; HST-GO-15320; 21171499; AC02-07CH11359
• OSTI ID: 1638183
• Alternate ID(s): OSTI ID: 1592143; OSTI ID: 1657940; OSTI ID: 1682237; OSTI ID: 1737615; OSTI ID: 1785350
• Report Number(s): DES-2018-0354; FERMILAB-PUB-19-627-AE; arXiv:1912.09133; TRN: US2201747
• Journal Information: Monthly Notices of the Royal Astronomical Society, Vol. 494, Issue 3; ISSN 0035-8711
• Publisher: Royal Astronomical Society
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
gravitational lensing: strong
quasars: general
methods: observational