GausSN: Bayesian Time-Delay Estimation for Strongly Lensed Supernovae

Fuente: arXiv
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Main Authors: Hayes, Erin E., Thorp, Stephen, Mandel, Kaisey S., Arendse, Nikki, Grayling, Matthew, Dhawan, Suhail
Format: Preprint
Published: 2023
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author Hayes, Erin E.
Thorp, Stephen
Mandel, Kaisey S.
Arendse, Nikki
Grayling, Matthew
Dhawan, Suhail
author_facet Hayes, Erin E.
Thorp, Stephen
Mandel, Kaisey S.
Arendse, Nikki
Grayling, Matthew
Dhawan, Suhail
contents We present GausSN, a Bayesian semi-parametric Gaussian Process (GP) model for time-delay estimation with resolved systems of gravitationally lensed supernovae (glSNe). GausSN models the underlying light curve non-parametrically using a GP. Without assuming a template light curve for each SN type, GausSN fits for the time delays of all images using data in any number of wavelength filters simultaneously. We also introduce a novel time-varying magnification model to capture the effects of microlensing alongside time-delay estimation. In this analysis, we model the time-varying relative magnification as a sigmoid function, as well as a constant for comparison to existing time-delay estimation approaches. We demonstrate that GausSN provides robust time-delay estimates for simulations of glSNe from the Nancy Grace Roman Space Telescope and the Vera C. Rubin Observatory's Legacy Survey of Space and Time (Rubin-LSST). We find that up to 43.6% of time-delay estimates from Roman and 52.9% from Rubin-LSST have fractional errors of less than 5%. We then apply GausSN to SN Refsdal and find the time delay for the fifth image is consistent with the original analysis, regardless of microlensing treatment. Therefore, GausSN maintains the level of precision and accuracy achieved by existing time-delay extraction methods with fewer assumptions about the underlying shape of the light curve than template-based approaches, while incorporating microlensing into the statistical error budget. GausSN is scalable for time-delay cosmography analyses given current projections of glSNe discovery rates from Rubin-LSST and Roman.
format Preprint
id arxiv_https___arxiv_org_abs_2311_17997
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle GausSN: Bayesian Time-Delay Estimation for Strongly Lensed Supernovae
Hayes, Erin E.
Thorp, Stephen
Mandel, Kaisey S.
Arendse, Nikki
Grayling, Matthew
Dhawan, Suhail
Cosmology and Nongalactic Astrophysics
Instrumentation and Methods for Astrophysics
We present GausSN, a Bayesian semi-parametric Gaussian Process (GP) model for time-delay estimation with resolved systems of gravitationally lensed supernovae (glSNe). GausSN models the underlying light curve non-parametrically using a GP. Without assuming a template light curve for each SN type, GausSN fits for the time delays of all images using data in any number of wavelength filters simultaneously. We also introduce a novel time-varying magnification model to capture the effects of microlensing alongside time-delay estimation. In this analysis, we model the time-varying relative magnification as a sigmoid function, as well as a constant for comparison to existing time-delay estimation approaches. We demonstrate that GausSN provides robust time-delay estimates for simulations of glSNe from the Nancy Grace Roman Space Telescope and the Vera C. Rubin Observatory's Legacy Survey of Space and Time (Rubin-LSST). We find that up to 43.6% of time-delay estimates from Roman and 52.9% from Rubin-LSST have fractional errors of less than 5%. We then apply GausSN to SN Refsdal and find the time delay for the fifth image is consistent with the original analysis, regardless of microlensing treatment. Therefore, GausSN maintains the level of precision and accuracy achieved by existing time-delay extraction methods with fewer assumptions about the underlying shape of the light curve than template-based approaches, while incorporating microlensing into the statistical error budget. GausSN is scalable for time-delay cosmography analyses given current projections of glSNe discovery rates from Rubin-LSST and Roman.
title GausSN: Bayesian Time-Delay Estimation for Strongly Lensed Supernovae
topic Cosmology and Nongalactic Astrophysics
Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2311.17997