The SDSS Discovery of a Strongly Lensed Post-Starburst Galaxy at z=0.766

TL;DR

This paper reports the discovery of a strongly lensed post-starburst galaxy at redshift 0.766 using SDSS data, demonstrating a method to identify galaxy-galaxy lenses from photometric surveys for future large-scale studies.

Contribution

First demonstration of identifying strong galaxy-galaxy lenses from SDSS photometric data using color and positional criteria, with implications for future surveys.

Findings

Discovered a lensing system with a post-starburst galaxy at z=0.766

Estimated the lensing galaxy's mass as approximately 1.2 x 10^12 solar masses

Showed that photometry-based selection can effectively find strong lenses in large surveys

Abstract

We present the first result of a survey for strong galaxy-galaxy lenses in Sloan Digital Sky Survey (SDSS) images. SDSS J082728.70+223256.4 was selected as a lensing candidate using selection criteria based on the color and positions of objects in the SDSS photometric catalog. Follow-up imaging and spectroscopy showed this object to be a lensing system. The lensing galaxy is an elliptical at z = 0.349 in a galaxy cluster. The lensed galaxy has the spectrum of a post-starburst galaxy at z = 0.766. The lensing galaxy has an estimated mass of $\sim 1.2 \times 10^{12} M_{\odot}$ and the corresponding mass to light ratio in the B-band is $\sim 26 M_{\odot}/L_{\odot}$ inside 1.1 effective radii of the lensing galaxy. Our study shows how catalogs drawn from multi-band surveys can be used to find strong galaxy-galaxy lenses having multiple lens images. Our strong lensing candidate selection based on photometry-only catalogs will be useful in future multi-band imaging surveys such as SNAP and LSST.