A Model-Independent Characterisation of Strong Gravitational Lensing by Observables
When light from a distant source object, like a galaxy or a supernova, travels towards us, it is deflected by massive objects that lie in its path. When the mass density of the deflecting object exceeds a certain threshold, multiple, highly distorted images of the source are observed. This strong gr...
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doaj-a4dd20d8c9164580aebd84a04142256d2020-11-25T01:26:24ZengMDPI AGUniverse2218-19972019-07-015717710.3390/universe5070177universe5070177A Model-Independent Characterisation of Strong Gravitational Lensing by ObservablesJenny Wagner0Astronomisches Rechen-Institut, Universität Heidelberg, Zentrum für Astronomie, Mönchhofstr. 12–14, 69120 Heidelberg, GermanyWhen light from a distant source object, like a galaxy or a supernova, travels towards us, it is deflected by massive objects that lie in its path. When the mass density of the deflecting object exceeds a certain threshold, multiple, highly distorted images of the source are observed. This strong gravitational lensing effect has so far been treated as a model-fitting problem. Using the observed multiple images as constraints yields a self-consistent model of the deflecting mass density and the source object. As several models meet the constraints equally well, we develop a lens characterisation that separates data-based information from model assumptions. The observed multiple images allow us to determine local properties of the deflecting mass distribution on any mass scale from one simple set of equations. Their solution is unique and free of model-dependent degeneracies. The reconstruction of source objects can be performed completely model-independently, enabling us to study galaxy evolution without a lens-model bias. Our approach reduces the lens and source description to its data-based evidence that all models agree upon, simplifies an automated treatment of large datasets, and allows for an extrapolation to a global description resembling model-based descriptions.https://www.mdpi.com/2218-1997/5/7/177cosmologydark mattergravitational lensingstrongmethodsanalyticalgalaxy clustersgeneralgalaxiesmass functionmethodsdata analysiscosmologydistance scale |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jenny Wagner |
spellingShingle |
Jenny Wagner A Model-Independent Characterisation of Strong Gravitational Lensing by Observables Universe cosmology dark matter gravitational lensing strong methods analytical galaxy clusters general galaxies mass function methods data analysis cosmology distance scale |
author_facet |
Jenny Wagner |
author_sort |
Jenny Wagner |
title |
A Model-Independent Characterisation of Strong Gravitational Lensing by Observables |
title_short |
A Model-Independent Characterisation of Strong Gravitational Lensing by Observables |
title_full |
A Model-Independent Characterisation of Strong Gravitational Lensing by Observables |
title_fullStr |
A Model-Independent Characterisation of Strong Gravitational Lensing by Observables |
title_full_unstemmed |
A Model-Independent Characterisation of Strong Gravitational Lensing by Observables |
title_sort |
model-independent characterisation of strong gravitational lensing by observables |
publisher |
MDPI AG |
series |
Universe |
issn |
2218-1997 |
publishDate |
2019-07-01 |
description |
When light from a distant source object, like a galaxy or a supernova, travels towards us, it is deflected by massive objects that lie in its path. When the mass density of the deflecting object exceeds a certain threshold, multiple, highly distorted images of the source are observed. This strong gravitational lensing effect has so far been treated as a model-fitting problem. Using the observed multiple images as constraints yields a self-consistent model of the deflecting mass density and the source object. As several models meet the constraints equally well, we develop a lens characterisation that separates data-based information from model assumptions. The observed multiple images allow us to determine local properties of the deflecting mass distribution on any mass scale from one simple set of equations. Their solution is unique and free of model-dependent degeneracies. The reconstruction of source objects can be performed completely model-independently, enabling us to study galaxy evolution without a lens-model bias. Our approach reduces the lens and source description to its data-based evidence that all models agree upon, simplifies an automated treatment of large datasets, and allows for an extrapolation to a global description resembling model-based descriptions. |
topic |
cosmology dark matter gravitational lensing strong methods analytical galaxy clusters general galaxies mass function methods data analysis cosmology distance scale |
url |
https://www.mdpi.com/2218-1997/5/7/177 |
work_keys_str_mv |
AT jennywagner amodelindependentcharacterisationofstronggravitationallensingbyobservables AT jennywagner modelindependentcharacterisationofstronggravitationallensingbyobservables |
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