Discovery of 19 strongly lensed, dual, or projected quasars in DESI-LS
We report the results of a follow-up spectroscopic confirmation of two lensed quasars, six dual quasars, and eleven projected quasars that had previously been identified as lensed-quasar candidates in our earlier work. The spectroscopic data were obtained from two different sources: Palomar 200-inch Double Spectrograph (P200/DBSP) in California and publicly available datasets, including SDSS and DESI-EDR. The two lensed quasars (both pairs) have the following properties: θ E = 1.″208, z s = 3.105; θ E = 0.″749, and z s = 2.395. The six dual quasars have redshifts ranging from 0.58 to 3.28 and projected separations ranging from 15.44 to 22.54 kpc, with a mean separation of 17.95 kpc. The eleven projected quasars have projected separations ranging from 10.96 to 39.07 kpc, with a mean separation of 22.64 kpc. Additionally, there are three likely lensed quasars that cannot be definitively confirmed, included for two reasons. Firstly, their image separations (0.″83, 0.″98, and 0.″93) are small compared to the seeing conditions during our observations (around 1.″2). Secondly, no high signal-to-noise (S/N) lensing galaxy can be feasibly detected in Legacy Survey Imaging. Improved spectroscopy and/or imaging would be needed to confirm their lensing nature.
Authors
- Dongdong Shi (ORCID: https://orcid.org/0000-0002-1991-1782)
- Zizhao He (ORCID: https://orcid.org/0000-0001-8554-9163)
- Libin Deng (ORCID: https://orcid.org/0000-0001-5863-3829)
- Y. Shu (ORCID: https://orcid.org/0000-0002-9063-698X)
- Rui Li (ORCID: https://orcid.org/0000-0002-3490-4089)
- Guoliang Li (ORCID: https://orcid.org/0000-0003-3798-8422)
- Qihang Chen (ORCID: https://orcid.org/0009-0008-4182-9401)
- Nan Li (ORCID: https://orcid.org/0000-0002-5588-4865)
Institutions
- University of Science and Technology of China (CN)
- Anhui University of Science and Technology (CN)
- Beijing Normal University (CN)
- Purple Mountain Observatory (CN)
- Zhengzhou University (CN)
- National Astronomical Observatories (CN)
Publication Details
- Journal
- Astronomy and Astrophysics
- Published
- 2025-02-01
- DOI
- https://doi.org/10.1051/0004-6361/202452731
- Citations
- 3
- Primary Topic
- Astronomy and Astrophysical Research
- Type
- article
- Field-Weighted Citation Impact
- 3.58
Funders
- National Science Foundation
- U.S. Department of Energy
- University of Pennsylvania
- Ohio State University
- University of Chicago
- University of Portsmouth
- University College London
- University of Sussex
- Deutsche Forschungsgemeinschaft
- National Natural Science Foundation of China
- Chinese Academy of Sciences
- Sun Yat-sen University
- China Postdoctoral Science Foundation
- Government of Jiangsu Province
- Financiadora de Estudos e Projetos
- University of Science and Technology of China
- University of Illinois at Urbana-Champaign
- Science and Technology Facilities Council
- Integrated Electronics Engineering Center, Binghamton University
- Argonne National Laboratory
- Fermilab
- Lawrence Berkeley National Laboratory
- SLAC National Accelerator Laboratory