J/ApJ/948/27ivo://CDS.VizieR/J/ApJ/948/27doi:10.26093/cds/vizier/ba-xm-vCDSLu J.Hsiao E.Y.Phillips M.M.Burns C.R.Ashall C.Morrell N.,Ng L.Kumar S.Shahbandeh M.Hoeflich P.Baron E.Uddin S.,Stritzinger M.D.Suntzeff N.B.Baltay C.Davis S.Diamond T.R.,Folatelli G.Forster F.Gagne J.Galbany L.Gall C.,Gonzalez-Gaitan S.Holmbo S.Kirshner R.P.Krisciunas K.Marion G.H.,Perlmutter S.Pessi P.J.Piro A.L.Rabinowitz D.Ryder S.D.,Sand D.J.2026-02-20T20:01:54Z2025-05-30T15:02:44ZCDS support team

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

cds-question@unistra.frsupernovaesurveysinfrared-astronomyspectroscopyredshiftedWe present the largest and most homogeneous collection of near-infrared (NIR) spectra of Type Ia supernovae (SNe Ia): 339 spectra of 98 individual SNe obtained as part of the Carnegie Supernova Project-II. These spectra, obtained with the FIRE spectrograph on the 6.5m Magellan Baade telescope, have a spectral range of 0.8-2.5{mu}m. Using this sample, we explore the NIR spectral diversity of SNe Ia and construct a template of spectral time series as a function of the light-curve-shape parameter, color stretch sBV. Principal component analysis is applied to characterize the diversity of the spectral features and reduce data dimensionality to a smaller subspace. Gaussian process regression is then used to model the subspace dependence on phase and light-curve shape and the associated uncertainty. Our template is able to predict spectral variations that are correlated with sBV, such as the hallmark NIR features: MgII at early times and the H-band break after peak. Using this template reduces the systematic uncertainties in K-corrections by ~90% compared to those from the Hsiao template. These uncertainties, defined as the mean K-correction differences computed with the color-matched template and observed spectra, are on the level of 4x10^-4^mag on average. This template can serve as the baseline spectral energy distribution for light-curve fitters and can identify peculiar spectral features that might point to compelling physics. The results presented here will substantially improve future SN Ia cosmological experiments, for both nearby and distant samples.2023ApJ...948...27Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/948/27CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/689/377 : SNIa as NIR standard candles from PAIRITEL (Wood-Vasey+, 2008)J/AJ/139/519 : Carnegie supernova project. SNe Ia (Contreras+, 2010)J/AJ/139/120 : Low-redshift Type-Ia supernovae (Folatelli+, 2010)J/ApJ/731/120 : Intrinsic SN Ia light curves (Mandel+, 2011)J/AJ/142/156 : The CSP (DR2): photometry of SNe Ia (Stritzinger+, 2011)J/ApJ/746/85 : THe HST Cluster Supernova Survey. V. (Suzuki+, 2012)J/A+A/578/A9 : Optical and NIR spectra of SN iPTF13ebh (Hsiao+, 2015)J/AJ/154/211 : The CSP (DR3): photometry of low-z SNe Ia (Krisciunas+, 2017)J/ApJ/848/56 : Relationships between SNe Ia & the host galaxies (Uddin+, 2017)J/ApJ/869/56 : Updated calibration of the CSP-I SNe Ia sample (Burns+, 2018)J/ApJ/859/101 : The supernovae Ia Pantheon sample (Scolnic+, 2018)J/A+A/615/A45 : NIR K-corrections (Stanishev+, 2018)J/A+A/630/A76 : SN2016hnk photometry and spectroscopy (Galbany+, 2019)J/ApJ/882/120 : CfA, CSP, BSP and LOSS spec. & phot. of SNe Ia (Wang+, 2019)J/ApJ/905/94 : Classif. for PS1-MDS SNe with SuperRAENN (Villar+, 2020)J/ApJ/923/237 : Opt and NIR phot. follow-up of iPTF SNIa (Johansson+, 2021)J/ApJ/914/57 : Follow-up Opt. and NIR obs. of the SNIa SN2015bp (Wyatt+, 2021)J/ApJ/938/110 : The Pantheon+ analysis: cosmological constraints (Brout+, 2022)J/ApJ/928/103 : Phot. and sp. obs. of type Ia SN 2015bo (Hoogendam+, 2022)J/ApJ/933/172 : NIR HST phot. of SNIa from the RAISIN survey (Jones+, 2022)J/ApJ/927/142 : Type Ia SN 2012ij opt. & NIR spectra (Li+, 2022)J/ApJ/938/83 : Multiepoch opt. obs. of 91T/99aa-like SNe Ia (Yang+, 2022)http://csp.obs.carnegiescience.edu/data : CSP data homepagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/948/27https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/948/27http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/948/27https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/948/27https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/948/27http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/948/27GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/948/27/tablea1 (Summary of SNe Ia and spectra used in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/948/27/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/948/27/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/948/27/tablea1?GETtext/xml+votable180.050000true190.0462518.05911110.0055555555555555566/24 425 928 2311 4288 4369 8196 8203 8323 8346 8763 12497 16612 17031 18011 18854 19993-19994 20712 21010 21175 21264 21833 22685 23027 23077 24227 24926 24957 25051 25070 25520 25675 25715 25749 25770 25782 26175 26451 26791 27239 27384 27418 27654 27738 27849 27926 27960 27966 28067 28230 28234 28241 28251 28294 30865 31348 31537 33387 33487 33681 33704 33971 34161 34531 34534 34884 35052 35717 35885 36128 37062 37429 37509 37537 37579 38621 38704 38723 38956 39664 40506 40805 40825 43339 43447 43873 43877 43991 45016 45126 45277 45746 46104 46636 46642 47382https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/948/27?format=asciiInfrareddefaultJ/ApJ/948/27/tablea1Summary of SNe Ia and spectra used in this workrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSupernova namemeta.id;meta.maincharTargetTargeted or untargeted?meta.codecharzhelio[0.0036/0.1] Heliocentric redshiftsrc.redshift;pos.heliocentricfloatTbmax[55893.24/57151.6] Time of B-band maximum, Modified Julian datedtime.epoch;em.opt.Bdoublee_Tbmax[0.02/1.01] Uncertainty in Tbmaxdstat.error;time.epoch;em.opt.BfloatsBV[0.48/1.3] Color-stretch parameter, B-V; obtained by fitting multi-band CSP light curves with SNooPyphot.color;obs.paramfloate_sBV[0.04/0.06] Uncertainty in sBVstat.error;phot.color;obs.paramfloatNsp[1/26] Spectra countsmeta.numberintDateUT Date, YYYY-MM-DDtime.epochcharMJD-sp[55911/57175.3] Modified Julian Date of spectral observationdtime.epochdoublePhase[-13.4/96.4] Epoch (phase, days since Tbmax) of spectral observationdtime.phasefloatExpTime[42.4/3804] Total on-target exposure time excluding overheadstime.duration;obs.exposuredoubleSNR-H[1.6/280] H-band signal-to-noise of spectrumstat.snr;em.IR.HfloatContWhether the spectrum is contaminated by host galaxymeta.codecharNEDNED column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainSimbadNameSimbad column added by the CDSmeta.idcharnullable