DESI-253.2534+26.8843: A New Einstein Cross Spectroscopically Confirmed with VLT/MUSE and Modeled with GIGA-Lens

Abstract

Gravitational lensing provides unique insights into astrophysics and cosmology, including the determination of galaxy mass profiles and constraining cosmological parameters. We present spectroscopic confirmation and lens modeling of the strong lensing system DESI-253.2534+26.8843, discovered in the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys data. This system consists of a massive elliptical galaxy surrounded by four blue images forming an Einstein Cross pattern. We obtained spectroscopic observations of this system using the Multi Unit Spectroscopic Explorer (MUSE) on ESO's Very Large Telescope (VLT) and confirmed its lensing nature. The main lens, which is the elliptical galaxy, has a redshift of $z_{L1}=0.636\pm 0.001$, while the spectra of the background source images are typical of a starburst galaxy and have a redshift of $z_s=2.597\pm 0.001$. Additionally, we identified a faint galaxy foreground of one of the lensed images, with a redshift of $z_{L2}=0.386$. We employed the GIGA-Lens modeling code to characterize this system and determined the Einstein radius of the main lens to be ${\theta }_E=2.520{{}^{\prime \prime }}_{-0.031}^{+0.032}$, which corresponds to a velocity dispersion of $\sigma$ = 379 $\pm$ 2 km s${}^{-1}$. Our study contributes to a growing catalog of this rare kind of strong lensing systems and demonstrates the effectiveness of spectroscopic integral field unit observations and advanced modeling techniques in understanding the properties of these systems.

Accepted for publication in ApJL

References in corpus (17)

• Improving the full spectrum fitting method: accurate convolution with Gauss-Hermite functions
• The MUSE second-generation VLT instrument
• UV-extended E-MILES stellar population models: young components in massive early-type galaxies
• The Data Processing Pipeline for the MUSE Instrument
• Cosmological Constraints from Strong Gravitational Lensing in Galaxy Clusters
• An excess of small-scale gravitational lenses observed in galaxy clusters
• Quenching of Star Formation in SDSS Groups: Centrals, Satellites, and Galactic Conformity
• Galaxy And Mass Assembly (GAMA): Environmental Quenching of Centrals and Satellites in Groups
• Strong lens systems search in the Dark Energy Survey using Convolutional Neural Networks
• Line-of-sight effects in strong gravitational lensing
• Substructure Detection Reanalyzed: Dark Perturber shown to be a Line-of-Sight Halo
• Gaia GraL: Gaia DR2 Gravitational Lens Systems. VI. Spectroscopic Confirmation and Modeling of Quadruply-Imaged Lensed Quasars
• Quantifying the Line-of-Sight Halo Contribution to the Dark Matter Convergence Power Spectrum from Strong Gravitational Lenses
• GIGA-Lens: Fast Bayesian Inference for Strong Gravitational Lens Modeling
• A New Einstein Cross: A Highly Magnified, Intrinsically Faint Lyman-Alpha Emitter at z=2.7
• A new Einstein Cross gravitational lens of a Lyman-break galaxy
• Discovery of two Einstein crosses from massive post--blue nugget galaxies at z>1 in KiDS

Cited by in corpus (2)

• A compact group lens modeled with GIGA-Lens: Enhanced inference for complex systems
• HerS-3: An Exceptional Einstein Cross Reveals a Massive Dark Matter Halo