The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs
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 Ke...
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ftosti:oai:osti.gov:1657940 2023-07-30T04:06:38+02:00 The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs Lemon, Cameron Suchyta, Eric D. 2022-05-30 application/pdf http://www.osti.gov/servlets/purl/1657940 https://www.osti.gov/biblio/1657940 https://doi.org/10.1093/mnras/staa652 unknown http://www.osti.gov/servlets/purl/1657940 https://www.osti.gov/biblio/1657940 https://doi.org/10.1093/mnras/staa652 doi:10.1093/mnras/staa652 2022 ftosti https://doi.org/10.1093/mnras/staa652 2023-07-11T09:46:33Z 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 percent of contaminant systems. Based on our spectroscopic follow-up, this variability information improves selection of lensed quasars and quasar pairs from 34-45 percent to 51–70 percent, 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 percent over a complete DES magnitude-limited sample, explained by the magnification bias and hence lower luminosity/more variable sources in quads. Other/Unknown Material sami SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Monthly Notices of the Royal Astronomical Society 494 3 3491 3511 |
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SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
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ftosti |
language |
unknown |
description |
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 percent of contaminant systems. Based on our spectroscopic follow-up, this variability information improves selection of lensed quasars and quasar pairs from 34-45 percent to 51–70 percent, 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 percent over a complete DES magnitude-limited sample, explained by the magnification bias and hence lower luminosity/more variable sources in quads. |
author |
Lemon, Cameron Suchyta, Eric D. |
spellingShingle |
Lemon, Cameron Suchyta, Eric D. The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs |
author_facet |
Lemon, Cameron Suchyta, Eric D. |
author_sort |
Lemon, Cameron |
title |
The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs |
title_short |
The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs |
title_full |
The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs |
title_fullStr |
The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs |
title_full_unstemmed |
The STRong lensing Insights into the Dark Energy Survey (STRIDES) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs |
title_sort |
strong lensing insights into the dark energy survey (strides) 2017/2018 follow-up campaign: discovery of 10 lensed quasars and 10 quasar pairs |
publishDate |
2022 |
url |
http://www.osti.gov/servlets/purl/1657940 https://www.osti.gov/biblio/1657940 https://doi.org/10.1093/mnras/staa652 |
genre |
sami |
genre_facet |
sami |
op_relation |
http://www.osti.gov/servlets/purl/1657940 https://www.osti.gov/biblio/1657940 https://doi.org/10.1093/mnras/staa652 doi:10.1093/mnras/staa652 |
op_doi |
https://doi.org/10.1093/mnras/staa652 |
container_title |
Monthly Notices of the Royal Astronomical Society |
container_volume |
494 |
container_issue |
3 |
container_start_page |
3491 |
op_container_end_page |
3511 |
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1772819417394053120 |