J/ApJ/815/58ivo://CDS.VizieR/J/ApJ/815/58doi:10.26093/cds/vizier.18150058CDSFakhouri 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)2018-01-05T08:56:32Z2016-04-01T07:56:57ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frsupernovaeWe 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.2015ApJ...815...58Fhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/815/58CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/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 pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/815/58https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/815/58http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/815/58https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/815/58https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/815/58http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/815/58GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/815/58/sne (List of the 49 supernovae in the final sample; table added by CDS)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/815/58/sne?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/815/58/sne?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/815/58/sne?GETtext/xml+votable180.050000true326.6256.41858330.0055555555555555566/166 4430 5999 8217 8344 8537 8573 8764 8788 9539 10040 10120 10144 10158 10401 11287 12349 13059 13334 13572 15096 17237 17315 17438 17513 17591 17644 17818 18017 19161 19187 19283 19387 19393 20051 20061 20080 21857 30174 31049 31418 32482 44635 44706 48346 48604 48925https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/815/58?format=asciidefaultJ/ApJ/815/58/table5Full data for the best supernovae pairs from the near-maximum R_V_=3.1 analysisrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSNaBest Supernova Pair, Object Ameta.id;meta.maincharSNbBest Supernova Pair, Object Bmeta.id.assoccharxi[0.1/4.6] Twinness value {xi} (Equation 1)stat.fit.paramdoubledM[-0.6/0.6] Overall brightness difference, {Delta}M=-2.5*log({kappa})magphot.mag;arith.diffdoubledE(B-V)[-0.5/0.4] Color differencemagphot.color;arith.diffdoubleJ/ApJ/815/58/sneList of the 49 supernovae in the final sample; table added by CDSSNName of the supernova Iameta.id;meta.maincharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintC13Display data from Childress+, 2013, J/ApJ/770/107, within 1"meta.ref.urlintnullableANumber of best pair with this object (A component)meta.numberintnullableBNumber of best pair with this object (B component)meta.numberintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.mainnullable_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainnullable