The University of Southampton
University of Southampton Institutional Repository

First cosmology results using type IA Supernovae from the Dark Energy Survey: Effects of chromatic corrections to supernova photometry on measurements of cosmological parameters

First cosmology results using type IA Supernovae from the Dark Energy Survey: Effects of chromatic corrections to supernova photometry on measurements of cosmological parameters
First cosmology results using type IA Supernovae from the Dark Energy Survey: Effects of chromatic corrections to supernova photometry on measurements of cosmological parameters
ABSTRACT
Calibration uncertainties have been the leading systematic uncertainty in recent analyses using type Ia Supernovae (SNe Ia) to measure cosmological parameters. To improve the calibration, we present the application of Spectral Energy Distribution (SED)-dependent “chromatic corrections" to the supernova light-curve photometry from the Dark Energy Survey (DES). These corrections depend on the combined atmospheric and instrumental transmission function for each exposure, and they affect photometry at the 0.01 mag (1%) level, comparable to systematic uncertainties in calibration and photometry. Fitting our combined DES and low-z SN Ia sample with Baryon Acoustic Oscillation (BAO) and Cosmic Microwave Background (CMB) priors for the cosmological parameters m (the fraction of the critical density of the universe comprised of matter) and w (the dark energy equation of state parameter), we compare those parameters before and after applying the corrections. We find the change in w and m due to not including chromatic corrections are 􀀀0:002 and 0:000, respectively, for the DES-SN3YR sample with BAO and CMB priors, consistent with a larger DES-SN3YR-like simulation, which has a w-change of 0:0005 with an uncertainty of 0:008 and an m change of 0:000 with an uncertainty of 0:002 . However, when considering samples on individual CCDs we find large redshift-dependent biases ( 0:02 in distance modulus) for supernova distances.
Key words: cosmology: dark energy, cosmology: observations, supernovae, techniques: photometric
cosmology: dark energy, cosmology: observations, supernovae, techniques: photometric
0035-8711
5329-5344
Sullivan, Mark
2f31f9fa-8e79-4b35-98e2-0cb38f503850
DES Collaboration
Sullivan, Mark
2f31f9fa-8e79-4b35-98e2-0cb38f503850

Sullivan, Mark , DES Collaboration (2019) First cosmology results using type IA Supernovae from the Dark Energy Survey: Effects of chromatic corrections to supernova photometry on measurements of cosmological parameters. Monthly Notices of the Royal Astronomical Society, 485 (4), 5329-5344. (doi:10.1093/mnras/stz619).

Record type: Article

Abstract

ABSTRACT
Calibration uncertainties have been the leading systematic uncertainty in recent analyses using type Ia Supernovae (SNe Ia) to measure cosmological parameters. To improve the calibration, we present the application of Spectral Energy Distribution (SED)-dependent “chromatic corrections" to the supernova light-curve photometry from the Dark Energy Survey (DES). These corrections depend on the combined atmospheric and instrumental transmission function for each exposure, and they affect photometry at the 0.01 mag (1%) level, comparable to systematic uncertainties in calibration and photometry. Fitting our combined DES and low-z SN Ia sample with Baryon Acoustic Oscillation (BAO) and Cosmic Microwave Background (CMB) priors for the cosmological parameters m (the fraction of the critical density of the universe comprised of matter) and w (the dark energy equation of state parameter), we compare those parameters before and after applying the corrections. We find the change in w and m due to not including chromatic corrections are 􀀀0:002 and 0:000, respectively, for the DES-SN3YR sample with BAO and CMB priors, consistent with a larger DES-SN3YR-like simulation, which has a w-change of 0:0005 with an uncertainty of 0:008 and an m change of 0:000 with an uncertainty of 0:002 . However, when considering samples on individual CCDs we find large redshift-dependent biases ( 0:02 in distance modulus) for supernova distances.
Key words: cosmology: dark energy, cosmology: observations, supernovae, techniques: photometric

Text
stz619 - Accepted Manuscript
Available under License Other.
Download (2MB)

More information

Accepted/In Press date: 26 February 2019
e-pub ahead of print date: 5 March 2019
Published date: June 2019
Keywords: cosmology: dark energy, cosmology: observations, supernovae, techniques: photometric

Identifiers

Local EPrints ID: 429081
URI: https://eprints.soton.ac.uk/id/eprint/429081
ISSN: 0035-8711
PURE UUID: 2a82aa0e-2fe1-4b75-8376-8f72a088a967
ORCID for Mark Sullivan: ORCID iD orcid.org/0000-0001-9053-4820

Catalogue record

Date deposited: 20 Mar 2019 17:30
Last modified: 31 Jul 2019 00:34

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×