J/ApJ/902/47ivo://CDS.VizieR/J/ApJ/902/47doi:10.26093/cds/vizier.19020047CDSMiller A.A.Yao Y.Bulla M.Pankow C.Bellm E.C.Cenko S.B.,Dekany R.Fremling C.Graham M.J.Kupfer T.Laher R.R.Mahabal A.A.,Masci F.J.Nugent P.E.Riddle R.Rusholme B.Smith R.M.Shupe D.L.,van Roestel J.Kulkarni S.R.2022-09-08T12:53:02Z2022-05-02T12:02:37ZCDS support team

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

cds-question@unistra.frsupernovaesurveysredshiftedWhile it is clear that Type Ia supernovae (SNe) are the result of thermonuclear explosions in C/O white dwarfs (WDs), a great deal remains uncertain about the binary companion that facilitates the explosive disruption of the WD. Here, we present a comprehensive analysis of a large, unique data set of 127 SNe Ia with exquisite coverage by the Zwicky Transient Facility (ZTF). High-cadence (six observations per night) ZTF observations allow us to measure the SN rise time and examine its initial evolution. We develop a Bayesian framework to model the early rise as a power law in time, which enables the inclusion of priors in our model. For a volume-limited subset of normal SNe Ia, we find that the mean power-law index is consistent with 2 in the rZTF-band ({alpha}_r_=2.01+/-0.02), as expected in the expanding fireball model. There are, however, individual SNe that are clearly inconsistent with {alpha}_r_=2. We estimate a mean rise time of 18.9 days (with a range extending from ~15 to 22d), though this is subject to the adopted prior. We identify an important, previously unknown, bias whereby the rise times for higher-redshift SNe within a flux-limited survey are systematically underestimated. This effect can be partially alleviated if the power-law index is fixed to {alpha}=2, in which case we estimate a mean rise time of 21.7 days (with a range from ~18 to 23d). The sample includes a handful of rare and peculiar SNe Ia. Finally, we conclude with a discussion of lessons learned from the ZTF sample that can eventually be applied to observations from the Vera C. Rubin Observatory.2020ApJ...902...47Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/902/47CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/716/712 : HST light curves of six SNe and Union2 (Amanullah+, 2010)J/MNRAS/410/585 : SN 2009dc BVRI light curves (Silverman+, 2011)J/MNRAS/446/3895 : The rising light curves of Type Ia supernovae (Firth+, 2015)J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)J/ApJ/826/144 : Follow-up observations of SNIa ASASSN-14lp (Shappee+, 2016)J/ApJ/859/101 : The supernovae Ia Pantheon sample (Scolnic+, 2018)J/ApJ/870/L1 : K2 obs. of type Ia supernova SN 2018oh (Dimitriadis+, 2019)J/ApJ/870/13 : K2 LC alternative analysis of ASASSN-18bt (Shappee+, 2019)J/ApJ/886/152 : ZTF early observations of Type Ia SNe. I. LCs (Yao+, 2019)J/A+A/634/A37 : TURTLS Light curves of ^56^Ni distributions (Magee+, 2020)J/ApJ/898/56 : UVOT, ZTF gri LCs & sp. of the SN Ia 2019yvq (Miller+, 2020)J/ApJ/902/48 : ZTF early obs. of type Ia supernovae. III. (Bulla+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/902/47https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/902/47http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/902/47https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/902/47https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/902/47http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/902/47GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/902/47/table3 (90% credible regions for marginalized model parameters (uninformative prior))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/902/47/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/902/47/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/902/47/table3?GETtext/xml+votable180.050000true214.202079758.48540860.0055555555555555566/2615 5622 9052 9067 9170 9178 9204-9205 9212 9223 9239 9268 9326 9361 9386 9424 9430 9470 9489 9520 9540 9564-9565 9608 9619 9639 9644 9678 9706 9726 9759 9768 9793 9808 9811 9824 9840 9971 10000 10004 10044 10060 10074-10075 10092 10112 10120 10154 10159 10175 10187 10200 10210 10595 10619 10637 10674 10710 10717 10728 10873 10944 11046 11109 11186 11199 11204 11222 11267 11269 11273 11297 11333 11385 11409 11451 11505 11534 11548 11551 11584 11614-11615 11619 11643 11668 11670 11685 11796 12037 12118 12124 12776 14526 14858 14874 14896 14973 15007 15018 15050 15054 15068 15070 15235 15258 15270-15271 15299 15308 15338 15349 15932 16060 16074 16079 16102 20223 32380 32486 32498 32520 32614 32670https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/902/47?format=asciidefaultJ/ApJ/902/47/table390% credible regions for marginalized model parameters (uninformative prior)trise5[9.68/21.15] The 5th percentile rise time (3)(2)dtime.intervalfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintZTFZTF identifiermeta.idcharprimaryNameTNS identifiermeta.id;meta.maincharz[0.018/0.17] Spectroscopic redshiftsrc.redshiftfloatn_zFlag on z (1)meta.notechartrise50[10/23.3] The 50th percentile rise time (2)(3)dtime.intervalfloattrise95[10.4/24.9] The 95th percentile rise time (3)(2)dtime.intervalfloatalphag5[0.02/3.15] The 5th percentile power-law index of g-band rise (2)(4)spect.indexfloatalphag50[0.26/4.4] The 50th percentile power-law index of g-band rise (2)(4)spect.indexfloatalphag95[1/6.5] The 95th percentile power-law index of g-band rise (2)(4)spect.indexfloatSimbadSimbad column added by the CDSmeta.ref.urlcharalphar5[0.02/3] The 5th percentile power-law index of r-band rise (2)(4)spect.indexfloatalphar50[0.2/5.3] The 50th percentile power-law index of r-band rise (2)(4)spect.indexfloatalphar95[0.84/6.9] The 95th percentile power-law index of r-band rise (2)(4)spect.indexfloatar-ag5[-3.3/0.7] The 5th percentile power-law index of g-r color evolution (2)(4)spect.indexfloatar-ag50[-2.9/2.6] The 50th percentile power-law index of g-r color evolution (2)(4)spect.indexfloatar-ag95[-1.5/3.9] The 95th percentile power-law index of g-r color evolution (2)(4)spect.indexfloatRelReliable model parameters flag; see Appendix B (y=reliable group; 51 occurrences)meta.codecharNormNormal SNe Ia flag; see Appendix C (n=peculiar; 7 occurrences)meta.codecharPapIDisplay data from Paper I (Yao+, 2019, J/ApJ/886/152)meta.ref.urlchar_RAPositions from Paper I (Yao+, 2019, J/ApJ/886/152) (right ascension part)degpos.eq.ra;meta.main_DEPositions from Paper I (Yao+, 2019, J/ApJ/886/152) (declination part)degpos.eq.dec;meta.mainJ/ApJ/902/47/table590% credible region for t_rise_ ({alpha}=2 prior)ZTFZTF identifiermeta.idcharprimaryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameTNS identifiermeta.id;meta.mainchartrise5[12.78/26.94] The 5th percentile rise time (1)dtime.intervalfloattrise50[13.16/28.56] The 50th percentile rise time (1)dtime.intervalfloattrise95[13.55/29.78] The 95th percentile rise time (1)dtime.intervalfloatRelReliable model parameters flag (y: 122 occurrences) (2)meta.codechar