# A novel 3D technique to study the kinematics of lensed galaxies

**Authors:** Francesca Rizzo, Simona Vegetti, Filippo Fraternali, Enrico Di Teodoro  
**arXiv:** [1809.07340](https://arxiv.org/abs/1809.07340)  
**Date:** 2018-09-19  
**Summary page:** https://www.summarizepaper.com/en/paper/1809.07340v1/

## Key points

- Rizzo et al. present a novel 3D Bayesian method for modeling the kinematics of strongly lensed galaxies using spatially-resolved emission-line observations
- The technique allows for simultaneous recovery of lens-mass distribution and source kinematics from the 3D data cube
- Simulations using OSIRIS observations were conducted on nine star-forming lensed galaxies with varying kinematic properties
- Results showed promising accuracy levels, with median relative accuracy at approximately 1% for inferred lens parameters and 2% for kinematic parameters
- The technique was tested against factors such as inclination angles, signal-to-noise ratios, and non-circular motions, with accuracy remaining within a few percent in most cases
- This new technique represents a significant advancement compared to previous methods used in this field
- It enables researchers to study degeneracies between lens parameters and source kinematics and estimate uncertainties on all model parameters consistently
- Rizzo et al.'s study provides valuable insights into understanding and modeling complex kinematics of strongly lensed galaxies
- Findings open up new possibilities for studying these systems in greater detail and improving our understanding of galaxy formation and evolution processes

## Summary

In their study, Rizzo et al. present a novel 3D Bayesian method for modeling the kinematics of strongly lensed galaxies using spatially-resolved emission-line observations. This technique allows for the simultaneous recovery of both the lens-mass distribution and the source kinematics directly from the 3D data cube. To test the effectiveness of their new method, the authors conducted simulations using OSIRIS observations for nine star-forming lensed galaxies with varying kinematic properties. The simulated rotation curves encompassed a range of shapes that represented different morphological galaxy types, ranging from dwarf to massive spiral galaxies. The results of their simulations demonstrated promising accuracy levels. The median relative accuracy on inferred lens and kinematic parameters was found to be at approximately 1% and 2%, respectively. Additionally, the authors tested the robustness of their technique against various factors such as inclination angles, signal-to-noise ratios, and the presence of warps or non-circular motions. In most cases, they found that the accuracy remained within a few percent. This new technique represents a significant advancement compared to previous methods used in this field. By deriving both the lens parameters and source kinematics from the same 3D data, it enables researchers to study potential degeneracies between these two aspects and estimate uncertainties on all model parameters consistently. Overall, Rizzo et al. 's study provides valuable insights into understanding and modeling complex kinematics of strongly lensed galaxies. Their findings open up new possibilities for studying these systems in greater detail and improving our understanding of galaxy formation and evolution processes.