J/ApJ/815/58 Spectrophotometric time series obs. of twin SNIa (Fakhouri+, 2015)
Improving cosmological distance measurements using twin Type Ia supernovae.
Fakhouri H.K., Boone K., Aldering G., Antilogus P., Aragon C., Bailey S.,
Baltay C., Barbary K., Baugh D., Bongard S., Buton C., Chen J.,
Childress M., Chotard N., Copin Y., Fagrelius P., Feindt U., Fleury M.,
Fouchez D., Gangler E., Hayden B., Kim A.G., Kowalski M., Leget P.-F.,
Lombardo S., Nordin J., Pain R., Pecontal E., Pereira R., Perlmutter S.,
Rabinowitz D., Ren J., Rigault M., Rubin D., Runge K., Saunders C.,
Scalzo R., Smadja G., Sofiatti C., Strovink M., Suzuki N., Tao C.,
Thomas R.C., Weaver B.A., (the Nearby Supernova Factory)
<Astrophys. J., 815, 58 (2015)>
=2015ApJ...815...58F 2015ApJ...815...58F (SIMBAD/NED BibCode)
ADC_Keywords: Supernovae
Keywords: cosmology: observations; supernovae: general
Abstract:
We introduce a method for identifying "twin" Type Ia supernovae
(SNeIa) and using them to improve distance measurements. This novel
approach to SN Ia standardization is made possible by
spectrophotometric time series observations from the Nearby Supernova
Factory (SNfactory). We begin with a well-measured set of SNe, find
pairs whose spectra match well across the entire optical window, and
then test whether this leads to a smaller dispersion in their absolute
brightnesses. This analysis is completed in a blinded fashion,
ensuring that decisions made in implementing the method do not
inadvertently bias the result. We find that pairs of SNe with more
closely matched spectra indeed have reduced brightness dispersion. We
are able to standardize this initial set of SNfactory SNe to
0.083±0.012mag, implying a dispersion of 0.072±0.010mag in the
absence of peculiar velocities. We estimate that with larger numbers
of comparison SNe, e.g., using the final SNfactory spectrophotometric
data set as a reference, this method will be capable of standardizing
high-redshift SNe to within 0.06-0.07mag. These results imply that at
least 3/4 of the variance in Hubble residuals in current SN cosmology
analyses is due to previously unaccounted-for astrophysical
differences among the SNe.
Description:
The spectrophotometric time series used in this study were obtained by
the Nearby Supernova Factory using the SuperNova Integral Field
Spectrograph (SNIFS) mounted on the south bent Cassegrain port of the
University of Hawaii 2.2m telescope on Mauna Kea.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
sne.dat 15 49 List of the 49 supernovae in the final sample;
table added by CDS
table5.dat 59 1009 Full data for the best supernovae pairs from
the near-maximum RV=3.1 analysis
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/A+A/568/A22 : Joint analysis of the SDSS-II & SNLS SNe Ia (Betoule+, 2014)
J/MNRAS/444/3258 : Velocities and EW of PTF SNe Ia (Maguire+, 2014)
J/MNRAS/438/1391 : Host galaxies of Type Ia SN from PTF (Pan+, 2014)
J/ApJ/770/107 : Host galaxies of SNIa from SNfactory (Childress+, 2013)
J/A+A/549/A8 : Atmospheric extinction data above Mauna Kea (Buton+, 2013)
J/MNRAS/425/1789 : Berkeley supernova Ia program. I. (Silverman+, 2012)
J/ApJ/750/99 : The Pan-STARRS1 photometric system (Tonry+, 2012)
J/ApJ/746/85 : THe HST Cluster Supernova Survey. V. (Suzuki+, 2012)
J/A+A/529/L4 : Reddening law of type Ia supernovae (Chotard+, 2011)
J/ApJ/731/120 : Intrinsic SN Ia light curves (Mandel+, 2011)
J/ApJS/192/1 : Light-curve parameters from the SNLS (Conley+, 2011)
J/ApJ/722/566 : SNe Ia host galaxies in SDSS-II SN survey (Lampeitl+, 2010)
J/MNRAS/406/782 : Type Ia supernovae luminosities (Sullivan+, 2010)
J/ApJ/699/L139 : Spectral parameters of SNe Ia (Wang+, 2009)
J/A+A/500/L17 : Spectral flux ratio of SN Ia (Bailey+, 2009)
http://snfactory.lbl.gov/ : The Nearby Supernova Factory home page
Byte-by-byte Description of file: sne.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- SN Name of the supernova Ia
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- SNa Best Supernova Pair, Object A
17- 31 A15 --- SNb Best Supernova Pair, Object B
33- 40 F8.6 --- xi [0.1/4.6] Twinness value ξ (Equation 1)
42- 50 F9.6 mag dM [-0.6/0.6] Overall brightness difference,
ΔM=-2.5*log(κ)
52- 59 F8.5 mag dE(B-V) [-0.5/0.4] Color difference
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 07-Mar-2016