MaNGA Strong Gravitational Lens Candidates

DR17
MaNGA
GALAXY
Michael S. Talbot, Joel R. Brownstein

This catalog contains information for strong galaxy-galaxy gravitational lens candidates and background galaxy candidates found within MaNGA galaxies contained within DR17 (see Talbot et al. 2018; Talbot et al. 2022 (preprint)). The candidates are spectroscopically detected within co-added foreground subtracted row-stacked-spectra (RSS), in which spectra are stacked across exposures from the same fiber located at the same dither position so a sigma-clipping method can reject transient signals. The target and candidate overview information, spectra information, and emission-line analysis information are split into three extensions. Nearly all candidate background galaxies are highly assured but only source grade A through C represent if a candidate is suspected to be lensed.

The summary file (silo_manga_detections-[SILO_VER].fits, available here) contains information on each candidate system, detections for each source or background candidate, and measurements for candidate emission lines. Data on spectra used in the lens search and spaxels constructed by SILO are recorded in files within each plate directory ([PLATE]/manga_[PLATE]_[IFU]_stack_data.fits). Plots of candidate emission lines with a signal-to-noise (SN) greater than four (flux-[PLATE]-[IFU]-[FIBER_POSITION]-[DETECTION_ID].pdf), SDSS images of the target (silo_manga_image-[PLATE]-[IFU]-[BACKGROUND_ID].pdf), and SN narrowband images of the candidate source plane (silo_manga_narrowband_image-[PLATE]-[IFU]-[BACKGROUND_ID].pdf) are located within the respective plate directory within the image directory (image/[PLATE]/).'

Note that SILO_VER was 1.0.3, released with DR17 in December 2021; it is still available here, but has been updated to version 1.0.4 in June 2022. Version 1.0.4 improves the computation of the probable strong lensing regime to evaluate which background galaxy candidates are spatially located within these new projections, and thus the low-resolution images and summary fits file are updated with both the new projection and grade information. We also recommend that you use the latest version available.