J/A+A/695/A264ivo://CDS.VizieR/J/A+A/695/A264doi:10.26093/cds/vizier.36950264CDSHarvey L.Maguire K.Burgaz U.Dimitriadis G.Sollerman J.Goobar A.,Johansson J.Nordin J.Rigault M.Smith M.Aubert M.Cartier R.,Chen P.Deckers M.Dhawan S.Galbany L.Ginolin M.Kenworthy W.D.,Kim Y.-L.Liu C.Miller A.Rosnet P.Senzel R.Terwel J.H.,Tomasella L.Kasliwal M.Laher R.R.Purdum J.Rusholme B.Smith R.2026-03-03T20:01:18Z2025-03-25T08:16:18ZCDS support team

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

cds-question@unistra.frsupernovaespectroscopyThe Zwicky Transient Facility SN Ia Data Release 2 provides a perfect opportunity to perform a thorough search for, and subsequent analysis of, high-velocity components in the SiII {lambda}6355 feature in the pre-peak regime. The source of such features remains unclear, with potential origins in circumstellar material or density/abundance enhancements intrinsic to the SN ejecta. Therefore, they may provide clues to the elusive progenitor and explosion scenarios of SNe Ia. We employ a Markov-Chain Monte Carlo fitting method followed by Bayesian Information Criterion testing to classify single and double SiII {lambda}6355 components in the DR2. The detection efficiency of our classification method is investigated through the fitting of simulated features, allowing us to place cuts upon spectral quality required for reliable classification. These simulations were also used to perform an analysis of the recovered parameter uncertainties and potential biases in the measurements.Within the 329 spectra sample that we investigate, we identify 85 spectra exhibiting SiII {lambda}6355 HVFs. We find that HVFs decrease in strength with phase relative to their photospheric counterparts - however, this decrease can occur at different phases for different objects. HVFs with larger velocity separations from the photosphere are seen to fade earlier leaving only the double components with smaller separations as we move towards maximum light. Our findings suggest that around three quarters of SN Ia spectra before ~11d show high-velocity components in the SiII {lambda}6355 with this dropping to around one third in the six days before maximum light. We observe no difference between the populations of SNe Ia that do and do not form SiII {lambda}6355 HVFs in terms of SALT2 light-curve parameter x1, peak magnitude, decline rate, host mass, or host colour, supporting the idea that these features are ubiquitous across the SN Ia population.2025A&A...695A.264Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/695/A264CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/694/A9 : Spectral Measurements of ZTF SN Ia DR2 (Burgaz+, 2025)J/A+A/694/A10 : ZTF SN Ia DR2 (Dimitriadis+, 2025)J/A+A/694/A11 : SN 2020alm spectrum (Terwel+, 2025)J/A+A/694/A12 : ZTF SN Ia DR2. secondary maximum in Type Ia SN (Deckers+, 2025)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/695/A264https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/695/A264http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/695/A264https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/695/A264https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/695/A264http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/695/A264GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/695/A264/pvf (Measurements of the 244 spectra not containing a HV feature in the SiII 6355 (table B1))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/695/A264/pvf?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/695/A264/pvf?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/695/A264/pvf?GETtext/xml+votable180.050000true66.0889438977.944803060.005555555555555556Cone search capability for table J/A+A/695/A264/hvf (Measurements of the 85 spectra containing a HV feature in the SiII 6355 (table B2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/695/A264/hvf?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/695/A264/hvf?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/695/A264/hvf?GETtext/xml+votable180.050000true112.0972030653.232946110.0055555555555555566/36 106 246 255 566 733 928 960 1006 1703 2089 2114 2185 2286 2292 2315 2418 2694 3919 4225 4390 4402 4452 4504-4505 4533 4836 4864 4928 4968 5129 5170 5183 5190 5342 5424 5564 5575 5583 5785 5905 5920 6089 6104 6112 6275 6331 6449 6509 6551 6558 6779 6900 6990 7106 7160 7183 7247 7256 7275 7424 7572 7674 7687 8095 8230 8239 8254 8267 8335 8543 8547 8567 8675 8876 8926 9005 9009 9031 9037 9072 9180 9197 9246 9354 9693 9695 9707 9763 9783 9806 9877 10000 10004 10124 10200 10207 10280 10373 10381 10389 10410 10434 10558 10637 10817 10944 10968 11186 11198 11204 11312 11573 11709 11715 11750 11794 11823 11826 11938 12210 12216 12256 12372 12394 12436 12572 13468 13472 13548 13617 13695 13714 13851 15007 15014 15035 15299 15917 16079 16571 16598 16727 16734 16765 16767 16781 16915 16981 17022 17138 17554 17598 17741 17745 17924 17941 17956 17991 18009 18036 18066 18182 18185 18214 18246 18429 18510 18663 18782 18818 18895 18901 18919 18971 19193 19214 19379 19625 19708 19891 19903 19941 20033 20159 20194 20236 20353 20359 20362 21095 21097 21181 21206 21208 21377 21814 21817 22357 22365 22374 22518 22561 22609 22676 22711 22716 22789 22980 23032 23051 23184 23226 23233 23271 23376 23790 23988 24070 24166 24399 24854 24871 25040 25244 25316 25511 25518 25650 25712 25894 26001 26028 26273 26574 26945 27031 27082 27092 27207 27271 27423 27471 27588 27671 27801 27826 27843 28004 28045 28075 28080 28137 28173 28247 28269 28313 28352 28374 28415 28661 30017 30037 30954 31060 31182 31515 31787 32165 32288 32322 32456 34793 34815 35828 36073 36159 36276 36470 36489 36755 38868 40283 40318 40360 40386 40415 40424 40804 40895 44541 44596 44645 44769 44792 45049 48110 48245 48426 48485 48963 49025 49136https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/695/A264?format=asciidefaultJ/A+A/695/A264/pvfMeasurements of the 244 spectra not containing a HV feature in the SiII 6355 (table B1)SimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintZTFInternal name within ZTF (ztf_name)meta.id;meta.maincharNameIAU designated name (iau_name)meta.idcharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainMJDModified Julian Date of spectrum (mjd)dtime.epochfloatPhasePhase of spectrum relative to date of maximum light (phase)dtime.phasefloate_PhaseUncertainty of phase (phase_err)dstat.error;time.phasefloataPVDepth of PV component (a_pv) (G1)stat.fit.paramfloate_aPVLower uncertainty of depth of PV component (a_pv_err_low)stat.errorfloatE_aPVUpper uncertainty of depth of PV component (a_pv_err_upp)stat.error;stat.maxfloatbPVCentroid of PV component (b_pv) (G1)0.1nmstat.fit.paramfloate_bPVLower uncertainty of centroid of PV component (b_pv_err_low)0.1nmstat.errorfloatE_bPVUpper uncertainty of centroid of PV component (b_pv_err_upp)0.1nmstat.error;stat.maxfloatcPVWidth of PV component (c_pv) (G1)0.1nmstat.fit.paramfloate_cPVLower uncertainty of width of PV component (c_pv_err_low)0.1nmstat.errorfloatE_cPVUpper uncertainty of width of PV component (c_pv_err_upp)0.1nmstat.error;stat.maxfloatpewPVPseudo equivalent width of PV component (pew_pv)0.1nmspect.line.eqWidthfloate_pewPVLower uncertainty of pseudo equivalent width of PV component (pew_pv_err_low)0.1nmstat.errorfloatE_pewPVUpper uncertainty of pseudo equivalent width of PV component (pew_pv_err_upp)0.1nmstat.error;stat.maxfloatTelSource telescope for spectrum (telescope)instr.telcharInstSource spectrograph for spectrum (instrument)meta.id;instrcharJ/A+A/695/A264/hvfMeasurements of the 85 spectra containing a HV feature in the SiII 6355 (table B2)SimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainMJDModified Julian Date of spectrum (mjd)dtime.epochfloatPhasePhase of spectrum relative to date of maximum light (phase)dtime.phasefloate_PhaseUncertainty of phase (phase_err)dstat.error;time.phasefloataPVDepth of PV component (a_pv) (G1)stat.fit.paramfloate_aPVLower uncertainty of depth of PV component (a_pv_err_low)stat.errorfloatE_aPVUpper uncertainty of depth of PV component (a_pv_err_upp)stat.error;stat.maxfloatbPVCentroid of PV component (b_pv) (G1)0.1nmstat.fit.paramfloate_bPVLower uncertainty of centroid of PV component (b_pv_err_low)0.1nmstat.errorfloatE_bPVUpper uncertainty of centroid of PV component (b_pv_err_upp)0.1nmstat.error;stat.maxfloatcPVWidth of PV component (c_pv) (G1)0.1nmstat.fit.paramfloate_cPVLower uncertainty of width of PV component (c_pv_err_low)0.1nmstat.errorfloatE_cPVUpper uncertainty of width of PV component (c_pv_err_upp)0.1nmstat.error;stat.maxfloataHVDepth of HV component (a_hv) (G1)stat.fit.paramfloate_aHVLower uncertainty of depth of HV component (a_hv_err_low)stat.errorfloatE_aHVUpper uncertainty of depth of HV component (a_hv_err_upp)stat.error;stat.maxfloatbHVCentroid of HV component (b_hv) (G1)0.1nmstat.fit.paramfloate_bHVLower uncertainty of centroid of HV component (b_hv_err_low)0.1nmstat.errorfloatE_bHVUpper uncertainty of centroid of HV component (b_hv_err_upp)0.1nmstat.error;stat.maxfloatcHVWidth of HV component (c_hv) (G1)0.1nmstat.fit.paramfloate_cHVLower uncertainty of width of HV component (c_hv_err_low)0.1nmstat.errorfloatE_cHVUpper uncertainty of width of HV component (c_hv_err_upp)0.1nmstat.error;stat.maxfloatpewPVPseudo equivalent width of PV component (pew_pv)0.1nmspect.line.eqWidthfloate_pewPVLower uncertainty of pseudo equivalent width of PV component (pew_pv_err_low)0.1nmstat.errorfloatE_pewPVUpper uncertainty of pseudo equivalent width of PV component (pew_pv_err_upp)0.1nmstat.error;stat.maxfloatpewHVPseudo equivalent width of HV component (pew_hv)0.1nmspect.line.eqWidthfloate_pewHVLower uncertainty of pseudo equivalent width of HV component (pew_hv_err_low)0.1nmstat.errorfloatE_pewHVUpper uncertainty of pseudo equivalent width of HV component (pew_hv_err_upp)0.1nmstat.error;stat.maxfloatRRatio of pews (pew_hv/pew_pv) (R)phot.flux;arith.ratiofloate_RLower uncertainty of pew ratio (R_err_low)stat.errorfloatE_RUpper uncertainty of pew ratio (R_err_upp)stat.error;stat.maxfloatVsepVelocity separation between the PV and HV components (vsep)km/sphys.velocfloate_VsepLower uncertainty of velocity separation (vsep_err_low)km/sstat.errorfloatE_VsepUpper uncertainty of velocity separation (vsep_err_upp)km/sstat.error;stat.maxfloatTelSource telescope for spectrum (telescope)instr.telcharInstSource spectrograph for spectrum (instrument)meta.id;instrcharZTFInternal name within ZTF (ztf_name)meta.id;meta.maincharNameIAU designated name (iau_name)meta.idchar