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Title: Multi-color light curves of type Ia supernovae on thecolor-magnitude diagram: A novel step toward more precise distance andextinction estimates

Abstract

We show empirically that fits to the color-magnituderelation of Type Ia supernovae after optical maximum can provide accuraterelative extragalactic distances. We report the discovery of an empiricalcolor relation for Type Ia light curves: During much of the first monthpast maximum, the magnitudes of Type Ia supernovae defined at a givenvalue of color index have a very small magnitude dispersion; moreover,during this period the relation between B magnitude and B-V color (or B-Ror B-I color) is strikingly linear, to the accuracy of existingwell-measured data. These linear relations can provide robust distanceestimates, in particular, by using the magnitudes when the supernovareaches a given color. After correction for light curve stretch factor ordecline rate, the dispersion of the magnitudes taken at the intercept ofthe linear color-magnitude relation are found to be around 0^m .08 forthe sub-sample of supernovae with (B_max - V_max) ?= 0^m 0.5, andaround 0^m.11 for the sub-sample with (B_max - V_max) ?= 0^m .2.This small dispersion is consistent with being mostly due toobservational errors. The method presented here and the conventionallight curve fitting methods can be combined to further improvestatistical dispersions of distance estimates. It can be combined withthe magnitude at maximum to deduce dust extinction. Theslopes of thecolor-magnitude relationmore » may also be used to identify intrinsicallydifferent SN Ia systems. The method provides a tool that is fundamentalto using SN Ia to estimate cosmological parameters such as the Hubbleconstant and the mass and dark energy content of theuniverse.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US)
Sponsoring Org.:
USDOE Director. Office of Science. Office of High EnergyPhysics
OSTI Identifier:
900774
Report Number(s):
LBNL-52341; astro-ph/0303341
R&D Project: PSUOPS; BnR: KA1301020; TRN: US0702380
DOE Contract Number:  
DE-AC02-05CH11231
Resource Type:
Journal Article
Journal Name:
The Astrophysical Journal
Additional Journal Information:
Journal Volume: 590; Journal Issue: 2; Related Information: Journal Publication Date: June 20,2003
Country of Publication:
United States
Language:
English
Subject:
72; ACCURACY; COLOR; DUSTS; SUPERNOVAE; UNIVERSE; supernova cosmology

Citation Formats

Wang, Lifan, Goldhaber, Gerson, Aldering, Greg, and Perlmutter, Saul. Multi-color light curves of type Ia supernovae on thecolor-magnitude diagram: A novel step toward more precise distance andextinction estimates. United States: N. p., 2003. Web. doi:10.1086/375020.
Wang, Lifan, Goldhaber, Gerson, Aldering, Greg, & Perlmutter, Saul. Multi-color light curves of type Ia supernovae on thecolor-magnitude diagram: A novel step toward more precise distance andextinction estimates. United States. doi:10.1086/375020.
Wang, Lifan, Goldhaber, Gerson, Aldering, Greg, and Perlmutter, Saul. Fri . "Multi-color light curves of type Ia supernovae on thecolor-magnitude diagram: A novel step toward more precise distance andextinction estimates". United States. doi:10.1086/375020. https://www.osti.gov/servlets/purl/900774.
@article{osti_900774,
title = {Multi-color light curves of type Ia supernovae on thecolor-magnitude diagram: A novel step toward more precise distance andextinction estimates},
author = {Wang, Lifan and Goldhaber, Gerson and Aldering, Greg and Perlmutter, Saul},
abstractNote = {We show empirically that fits to the color-magnituderelation of Type Ia supernovae after optical maximum can provide accuraterelative extragalactic distances. We report the discovery of an empiricalcolor relation for Type Ia light curves: During much of the first monthpast maximum, the magnitudes of Type Ia supernovae defined at a givenvalue of color index have a very small magnitude dispersion; moreover,during this period the relation between B magnitude and B-V color (or B-Ror B-I color) is strikingly linear, to the accuracy of existingwell-measured data. These linear relations can provide robust distanceestimates, in particular, by using the magnitudes when the supernovareaches a given color. After correction for light curve stretch factor ordecline rate, the dispersion of the magnitudes taken at the intercept ofthe linear color-magnitude relation are found to be around 0^m .08 forthe sub-sample of supernovae with (B_max - V_max) ?= 0^m 0.5, andaround 0^m.11 for the sub-sample with (B_max - V_max) ?= 0^m .2.This small dispersion is consistent with being mostly due toobservational errors. The method presented here and the conventionallight curve fitting methods can be combined to further improvestatistical dispersions of distance estimates. It can be combined withthe magnitude at maximum to deduce dust extinction. Theslopes of thecolor-magnitude relation may also be used to identify intrinsicallydifferent SN Ia systems. The method provides a tool that is fundamentalto using SN Ia to estimate cosmological parameters such as the Hubbleconstant and the mass and dark energy content of theuniverse.},
doi = {10.1086/375020},
journal = {The Astrophysical Journal},
number = 2,
volume = 590,
place = {United States},
year = {2003},
month = {1}
}