J/ApJ/914/57ivo://CDS.VizieR/J/ApJ/914/57doi:10.26093/cds/vizier.19140057CDSWyatt S.D.Sand D.J.Hsiao E.Y.Burns C.R.Valenti S.Bostroem K.A.,Lundquist M.Galbany L.Lu J.Ashall C.Diamond T.R.Filippenko A.V.,Graham M.L.Hoeflich P.Kirshner R.P.Krisciunas K.Marion G.H.,Morrell N.Persson S.E.Phillips M.M.Stritzinger M.D.Suntzeff N.B.,Taddia F.2023-05-26T09:13:12Z2022-12-29T09:42:04ZCDS support team

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

cds-question@unistra.frsupernovaephotometryvisible-astronomyspectroscopyinfrared-astronomyUnburned carbon is potentially a powerful probe of Type Ia supernova (SN) explosion mechanisms. We present comprehensive optical and near-infrared (NIR) data on the "transitional" Type Ia SN 2015bp. An early NIR spectrum (t=-9.9 days with respect to B-band maximum) displays a striking CI 1.0693{mu}m line at 11.9x10^3^km/s, distinct from the prominent Mg ii 1.0927 {mu}m feature, which weakens toward maximum light. SN 2015bp also displays a clear CII 6580{AA} notch early (t=-10.9 days) at 13.2x10^3^km/s, consistent with our NIR carbon detection. At M_B_=-18.46, SN 2015bp is less luminous than a normal SNIa and, along with iPTF 13ebh, is the second member of the transitional subclass to display prominent early-time NIR carbon absorption. We find it unlikely that the CI feature is misidentified HeI 1.0830{mu}m because this feature grows weaker toward maximum light, while the helium line produced in some double-detonation models grows stronger at these times. Intrigued by these strong NIR carbon detections, but lacking NIR data for other SNe Ia, we investigated the incidence of optical carbon in the sample of nine transitional SNe Ia with early-time data (t<~-4 days). We find that four display CII6580{AA}, while two others show tentative detections, in line with the SN Ia population as a whole. We conclude that at least ~50% of transitional SNe Ia in our sample do not come from sub-Chandrasekhar-mass explosions due to the clear presence of carbon in their NIR and optical spectra.2021ApJ...914...57Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/914/57CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/eso : ESO Science Archive Catalog (ESO, 1991-2022)II/183 : UBVRI Photometric Standards (Landolt 1992)J/MNRAS/377/1531 : Optical & IR photometry of SN 2004eo (Pastorello+, 2007)J/A+A/465/71 : 21cm observations of 452 galaxies (Theureau+, 2007)J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)J/ApJ/699/L139 : Spectral parameters of SNe Ia (Wang+, 2009)J/AJ/139/519 : Carnegie supernova project. SNe Ia (Contreras+, 2010)J/AJ/139/120 : Low-redshift Type-Ia supernovae (Folatelli+, 2010)J/MNRAS/413/813 : ATLAS3D project. I. (Cappellari+, 2011)J/ApJS/192/1 : Light-curve parameters from the SNLS (Conley+, 2011)J/MNRAS/410/585 : SN 2009dc BVRI light curves (Silverman+, 2011)J/AJ/143/126 : Spectroscopy of 462 nearby Type Ia SNe (Blondin+, 2012)J/ApJ/745/74 : Pre-maximum spectra of type Ia SNe (Folatelli+, 2012)J/MNRAS/425/1819 : Berkeley supernova Ia program. II. (Silverman+, 2012)J/ApJ/746/85 : THe HST Cluster Supernova Survey. V. (Suzuki+, 2012)J/ApJ/773/53 : Type Ia SNe spectroscopy by the CSP (Folatelli+, 2013)J/A+A/554/A27 : 2011fe spectrophotometric time series (Pereira+, 2013)J/MNRAS/444/3258 : Velocities and EW of PTF SNe Ia (Maguire+, 2014)J/A+A/578/A9 : Optical and NIR spectra of SN iPTF13ebh (Hsiao+, 2015)J/A+A/579/A40 : PESSTO catalog (Smartt+, 2015)J/ApJ/869/56 : Updated calibration of the CSP-I SNIa sample (Burns+, 2018)J/A+A/611/A58 : SN 2007on and SN 2011iv light curves (Gall+, 2018)J/ApJ/874/150 : The first 3yrs of DES-SN (DES-SN3YR) (Brout+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/914/57https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/914/57http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/914/57https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/914/57https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/914/57http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/914/57GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tap2.381800341673347e-19 6.090060298487514e-19OpticalInfrareddefaultJ/ApJ/914/57/table1Optical photometry of SN 2015bp in the natural Swope systeme_Vmag[0.005/0.02] Uncertainty on the Vmagmagstat.error;phot.magfloatrmag[13.73/19.25] Sloan r-band magnitudemagphot.mag;em.opt.Rfloate_rmag[0.005/0.03] Uncertainty on the rmagmagstat.error;phot.magfloatimag[14.19/19.08] Sloan i-band magnitudemagphot.mag;em.opt.Ifloate_imag[0.005/0.04] Uncertainty on the imagmagstat.error;phot.magfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateDate of observation (UT)time.epochnullableMJD[57100.3/57249.1] Modified Julian Datedtime.epochdoublePhase[-11.38/137.31] Orbital phasetime.phasefloatumag[13.88/18.8]? Sloan u-band magnitudemagphot.mag;em.opt.Ufloatnullablee_umag[0.005/0.03]? Uncertainty on the umagmagstat.error;phot.magfloatnullableBmag[13.79/18.62] Johnson B magnitudemagphot.mag;em.opt.Bfloate_Bmag[0.005/0.02] Uncertainty on the Bmagmagstat.error;phot.magfloatgmag[14.44/20.88] Sloan g-band magnitudemagphot.mag;em.opt.Bfloate_gmag[0.005/0.15] Uncertainty on the gmagmagstat.error;phot.magfloatVmag[13.78/18.57] Johnson V magnitudemagphot.mag;em.opt.VfloatJ/ApJ/914/57/table3Journal of optical spectroscopic observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation date (UT)time.epoch;obsnullableMJD[57101.3/57281] Modified Julian Datedtime.epochfloatInstInstrument (1)meta.id;instrchartmaxB[-10.9/168.8] Time relative to B_max_ (JD-2457112.71)dtime.intervalfloattint[10/45]? Total integration timemintime.expofloatnullablef_tintFlag on tint (2)meta.codecharFileNameName of the CSV file in subdirectory "spopt"meta.id;meta.filecharSpInteractive optical spectrum plotmeta.ref.urlcharJ/ApJ/914/57/table4Journal of NIR spectroscopic observationsFileNameName of the CSV file in subdirectory "spnir"meta.id;meta.filecharSpInteractive NIR spectrum plotmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateObservation date (UT)time.epoch;obsnullableMJD[57102.3/57174.2] Modified Julian Datedtime.epochfloatInstInstrument (1)meta.id;instrchartmaxB[-9.9/62]? Time relative to B_max_ (JD-2457112.71)dtime.intervalfloatnullabletint[8.4/50]? Total integration timemintime.expofloatnullable