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Title: Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2

Abstract

We present an updated version of the Multicolor Light Curve Shape method to measure distances to type Ia supernovae (SN Ia), incorporating new procedures for K-correction and extinction corrections. We also develop a simple model to disentangle intrinsic color variations and reddening by dust, and expand the method to incorporate U-band light curves and to more easily accommodate prior constraints on any of the model parameters. We apply this method to 133 nearby SN Ia, including 95 objects in the Hubble flow (cz {ge} 2500 km s{sup -1}), which give an intrinsic dispersion of less than 7% in distance. The Hubble flow sample, which is of critical importance to all cosmological uses of SN Ia, is the largest ever presented with homogeneous distances. We find the Hubble flow supernovae with H{sub 0}d{sub SN} {ge} 7400 km s{sup -1} yield an expansion rate that is 6.5 {+-} 1.8% lower than the rate determined from supernovae within that distance, and this can have a large effect on measurements of the dark energy equation of state with SN Ia. Peculiar velocities of SN Ia host galaxies in the rest frame of the Local Group are consistent with the dipole measured in the Cosmicmore » Microwave Background. Direct fits of SN Ia that are significantly reddened by dust in their host galaxies suggest their mean extinction law may be described by R{sub V} {approx_equal} 2.7, but optical colors alone provide weak constraints on R{sub V}.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
896923
Report Number(s):
SLAC-PUB-12273
TRN: US200705%%69
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COLOR; DIPOLES; DUSTS; GALAXIES; RELICT RADIATION; SHAPE; SUPERNOVAE; ASTROPHYSICS; Astrophysics,ASTRO

Citation Formats

Jha, Saurabh, /KIPAC, Menlo Park, Riess, Adam G., /Baltimore, Space Telescope Sci., Kirshner, Robert P., and /Harvard-Smithsonian Ctr. Astrophys. Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2. United States: N. p., 2007. Web. doi:10.1086/512054.
Jha, Saurabh, /KIPAC, Menlo Park, Riess, Adam G., /Baltimore, Space Telescope Sci., Kirshner, Robert P., & /Harvard-Smithsonian Ctr. Astrophys. Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2. United States. doi:10.1086/512054.
Jha, Saurabh, /KIPAC, Menlo Park, Riess, Adam G., /Baltimore, Space Telescope Sci., Kirshner, Robert P., and /Harvard-Smithsonian Ctr. Astrophys. Fri . "Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2". United States. doi:10.1086/512054. https://www.osti.gov/servlets/purl/896923.
@article{osti_896923,
title = {Improved Distances to Type Ia Supernovae withMulticolor Light Curve Shapes: MLCS2k2},
author = {Jha, Saurabh and /KIPAC, Menlo Park and Riess, Adam G. and /Baltimore, Space Telescope Sci. and Kirshner, Robert P. and /Harvard-Smithsonian Ctr. Astrophys.},
abstractNote = {We present an updated version of the Multicolor Light Curve Shape method to measure distances to type Ia supernovae (SN Ia), incorporating new procedures for K-correction and extinction corrections. We also develop a simple model to disentangle intrinsic color variations and reddening by dust, and expand the method to incorporate U-band light curves and to more easily accommodate prior constraints on any of the model parameters. We apply this method to 133 nearby SN Ia, including 95 objects in the Hubble flow (cz {ge} 2500 km s{sup -1}), which give an intrinsic dispersion of less than 7% in distance. The Hubble flow sample, which is of critical importance to all cosmological uses of SN Ia, is the largest ever presented with homogeneous distances. We find the Hubble flow supernovae with H{sub 0}d{sub SN} {ge} 7400 km s{sup -1} yield an expansion rate that is 6.5 {+-} 1.8% lower than the rate determined from supernovae within that distance, and this can have a large effect on measurements of the dark energy equation of state with SN Ia. Peculiar velocities of SN Ia host galaxies in the rest frame of the Local Group are consistent with the dipole measured in the Cosmic Microwave Background. Direct fits of SN Ia that are significantly reddened by dust in their host galaxies suggest their mean extinction law may be described by R{sub V} {approx_equal} 2.7, but optical colors alone provide weak constraints on R{sub V}.},
doi = {10.1086/512054},
journal = {Astrophysical Journal},
number = ,
volume = ,
place = {United States},
year = {Fri Jan 05 00:00:00 EST 2007},
month = {Fri Jan 05 00:00:00 EST 2007}
}