# Gravitational lensing of the farthest known supernova SN1997ff

**Authors:** Edvard Moertsell, Christofer Gunnarsson, Ariel Goobar  
**arXiv:** [astro-ph/0105355](https://arxiv.org/abs/astro-ph/0105355)  
**Date:** 2001-05-21  
**Summary page:** https://www.summarizepaper.com/en/paper/astro-ph--0105355v2/

## Key points

- Gravitational lensing effects on Type Ia supernova SN1997ff investigated
- Adjusting mass and velocity dispersion of lensing galaxies allows for a wide range of magnifications
- Main objective is to constrain the redshift-distance relation using SN1997ff
- Detailed modeling of intervening galaxies necessary to control for systematic effects from gravitational lensing
- Current limited knowledge about lensing galaxies makes it challenging to accurately determine values of Omega_M and Omega_Lambda, grey dust obscuration, or luminosity evolution in Type Ia supernovae
- Understanding and accounting for gravitational lensing effects is crucial when using distant supernovae as cosmological probes
- More comprehensive modeling techniques and improved knowledge about intervening galaxies needed for accurate measurements and meaningful conclusions about fundamental cosmological parameters.

## Summary

In their study, Edvard Moertsell, Christofer Gunnarsson, and Ariel Goobar investigate the effects of gravitational lensing caused by intervening galaxies on a Type Ia supernova known as SN1997ff. This supernova was discovered in the Hubble Deep Field North and has a redshift value of z=1.7. The researchers find that by adjusting the mass and/or velocity dispersion normalization of the lensing galaxies, it is possible to obtain a wide range of magnifications. The main objective of this study is to use SN1997ff to constrain the redshift-distance relation. Detailed modeling of the intervening galaxies is necessary to control for systematic effects from gravitational lensing; however, due to our current limited knowledge about these lensing galaxies, it is challenging to accurately determine values of Omega_M and Omega_Lambda or place strict constraints on grey dust obscuration or luminosity evolution in Type Ia supernovae. Overall, this research highlights the importance of understanding and accounting for gravitational lensing effects when using distant supernovae as cosmological probes. It emphasizes the need for more comprehensive modeling techniques and improved knowledge about intervening galaxies in order to make accurate measurements and draw meaningful conclusions about fundamental cosmological parameters.