J/A+A/694/A12ivo://CDS.VizieR/J/A+A/694/A12doi:10.26093/cds/vizier.36940012CDSDeckers M.Maguire K.Shingles L.Dimitriadis G.Rigault M.Smith M.,Goobar A.Nordin J.Johansson J.Amenouche M.Burgaz U.Dhawan S.,Ginolin M.Harvey L.Kenworthy W.D.Kim Y.-L.Laher R.R.Luo N.,Kulkarni S.R.Masci F.J.Galbany L.Mueller-Bravo T.E.Nugent P.E.,Pletskova N.Purdum J.Racine B.Sollerman J.Terwel J.H.2025-05-21T20:01:18Z2025-02-14T09:19:09ZCDS support team

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

cds-question@unistra.frsupernovaephotometryvisible-astronomyType Ia supernova (SN Ia) light curves have a secondary maximum that exists in the r, i, and near-infrared filters. The secondary maximum is relatively weak in the r band, but holds the advantage that it is accessible, even at high redshift. We used Gaussian Process fitting to parameterise the light curves of 893 SNe Ia from the Zwicky Transient Facility's (ZTF) second data release (DR2), and we were able to extract information about the timing and strength of the secondary maximum. We found >5{sigma} correlations between the light curve decline rate ({DELTA}m15(g)) and the timing and strength of the secondary maximum in the r band. Whilst the timing of the secondary maximum in the i band also correlates with {DELTA}m15(g), the strength of the secondary maximum in the i band shows significant scatter as a function of {DELTA}m15(g). We found that the transparency timescales of 97 per cent of our sample are consistent with double detonation models, and that SNe Ia with small transparency timescales (<32d) reside predominantly in locally red environments. We measured the total ejected mass for the normal SNe Ia in our sample using two methods, and both were consistent with medians of 1.3+/-0.3 and 1.2+/-0.2 solar masses. We find that the strength of the secondary maximum is a better standardisation parameter than the SALT light curve stretch (x1). Finally, we identified a spectral feature in the r band as FeII, which strengthens during the onset of the secondary maximum. The same feature begins to strengthen at <3d post maximum light in 91bg-like SNe. Finally, the correlation between x1 and the strength of the secondary maximum was best fit with a broken line, with a split at x0^1^=-0.5+/-0.2, suggestive of the existence of two populations of SNe Ia.2025A&A...694A..12Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/694/A12CatalogResearchIsServedByTAP 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)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/694/A12https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/694/A12http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/694/A12https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/694/A12https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/694/A12http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/694/A12GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/694/A12/2ndmax2 (Properties of the secondary maximum derived from the Gaussian process fits)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/694/A12/2ndmax2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/694/A12/2ndmax2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/694/A12/2ndmax2?GETtext/xml+votable180.050000true153.4511288938.763123060.0055555555555555566/24 36 73 87-88 106 176 188 192 231 235 246 248 255 380 387 523 551 574 580 635 754 769 887 911 928 960 969 972 981 988 991-992 1006 1016 1042 1156 1174 1194 1208 1524 1563 1583 1598 1642 1667-1668 1672 1685 1703 1716 1728 1819 1847 1861 1881 1888 1916 2041 2058 2071 2128 2200 2236 2270 2286 2292 2308 2315 2317 2372 2396 2418 2466 2504-2505 2527 2616 2651 2694 2738 2811 2846 2884 2937 3074 3082 3106 3493 3573 3630 3791 3941 3956 3977 4246 4287 4314 4369 4376 4408 4442 4449 4500 4505 4637 4739 4796 4928 5120 5150 5184 5204 5209 5272 5342 5355 5359 5392 5394 5422 5424 5470 5514 5529 5553 5564 5575 5583 5603 5629 5668 5700-5701 5703 5716 5725 5754 5839 5884 5900 5905 5920 5922 5936 5957 5982-5983 6042 6057 6081 6089 6104 6112 6119 6121 6131 6184 6220 6234 6275-6276 6302 6331 6473 6499 6558 6585 6743 6749-6751 6779 6846 6852 6888 6900 6990-6991 7010 7012 7020 7022 7024 7041 7051 7061 7066 7076 7089 7106 7156 7160 7247 7263 7268 7275 7278 7280 7291 7295 7345 7401 7424 7485 7501 7523 7539 7572 7653 7674 7683 7687 7712 7806 7959 7978 8016 8027 8029 8050 8170 8210 8215 8230-8231 8239 8242 8253 8264 8267 8273 8335 8346 8356 8386 8426 8443 8453 8512 8514 8520-8521 8526 8537 8543 8545 8550 8557 8567 8580 8586 8626 8735 8747 8757-8758 8764 8778 8789 8831 8857 8908 8917 8948 8957 9004-9005 9020 9067 9098 9102 9122 9178-9180 9197 9205 9239 9246 9282 9296 9327 9386 9402 9454 9470 9480 9495 9535 9542-9543 9567 9621 9644 9666 9672 9686 9693 9695 9706-9707 9734 9746 9759 9763-9764 9806 9812 9820 9825 9835 9837 9847 9859 9878 9938-9939 9947 9981 9984 9989 9994 10000 10004 10030 10058 10115 10124 10159 10178 10200 10204 10207 10280 10329 10343 10345 10364 10373 10381 10403 10446 10481 10484 10486 10520 10534 10593 10637 10665-10666 10670 10720 10794 10825 10858 10873 10879 10904 10925 10951 10968 10981 11012 11056 11062-11063 11105 11178 11181 11186 11198 11214 11223 11246 11360 11362 11379 11396 11405 11414-11415 11433 11441 11476 11514 11522 11551 11564 11568 11592 11614 11630 11643 11712 11715 11720 11730 11734 11794-11796 11820 11822-11823 11826 11854-11855 11908 11938 11975 12008 12048 12122 12138 12154 12188 12199 12209-12210 12216 12256 12267 12372 12449 12477 12497 12508 12572 12579 12617 12642 12646-12647 12668 12905 13021 13065 13100 13206 13321 13324 13326 13468 13472 13619 13631 13635 13677 13714 13720 13737 13757 13761 13784 13789 13817 13832 13851 13917 13931 13944-13945 14020 14103 14499 14523 14582-14583 14764 14768 14815 14829 14841 14874 14892-14893 14903 14925 14937 15007 15014 15032 15037 15070-15071 15096 15100 15107 15154 15162 15175 15194 15203 15211 15235 15271-15272 15299 15338 15543 15551 15746 15917-15918 16058 16079 16111 16122 16126 16138 16141 16291 16296 16304 16312 16605 16610 16693 16718 16781 16852 16860 17069 17310 17360 17495 17523 17573 17598 17636 17658 17725 17741-17742 17745 17752 17787 17796 17810 17909 17924 17956 17986 17991 17994 18009 18018 18036 18038 18066 18077 18122 18156 18168 18175 18182 18185-18186 18201 18269 18313 18315 18327 18365 18375 18379 18409 18420 18429 18479 18510 18535 18653 18680 18703 18894-18895 18901 18903 18905 18922 18935 18939-18940 18949 19034 19041 19090 19107 19122 19130 19148 19175 19189 19199 19206 19214 19224 19242 19336 19362 19379 19432 19499 19522 19550 19625 19708 19729 19761 19790 19802 19807 19824 19830 19847 19903 19917 19927 19979 20007 20033 20050 20083-20084 20127 20171 20218 20223 20236 20270 20334 20353 20359 20362 20390-20391 20436 21097 21141 21143-21144 21230 21270 21280 21378 21772-21773 21790-21791 21817 21826 21847 21862 21865 21942 21960 22313 22357 22365 22555 22557 22588 22676 22696 22850 22904 22921 23026 23032 23038 23078-23079 23184 23201 23217 23229 23233 23242 23247 23265 23271 23291 23383 23420 23705 23777 23873 23957 23988 24040 24056 24070 24140 24145 24166 24226 24372 24388 24399 24910 24954 24989 25040 25054 25063 25086 25511 25650 25959 26028 26061 26078 26144 26155 26247 26284 26366 26444 26556 26559 26561 26580 26742 26781 26796 26950 27024 27067 27079 27186 27207 27471 27541 27588 27605 27634 27645 27714 27729 27820 28004 28027 28075 28080 28146 28202 28251 28285 28313 28319 28335 28374 28414 28422 28454 28460 28468 28490 28531 28554 28587 28612-28613 28660-28661 29673 29838 29906 30034 30122 30131 30137 30545 30578 30954 31055 31171 31319 31326 31373 31384 31462 31515 31568 31661 31674 31693 31703 31721 31787 31891 31955 31958 31964 31975 31983 31990 32131-32132 32143 32196 32288 32333 32336 32380 32401 32413 32426 32456 32465 32471 32486 32494 32511 32513 32520 32546 32555 32602 32605 32618 32689 32704-32705 32739 32760 35695 35820 35828 36028 36106 36159 36276 36330 36491 36513 36539 36567 36625 36667 36712-36713 36755 36761 36854 40327 40412 40751 40895 44359 44487 45049 48430 48483 48485 48545 48594 48688 49005 49094 49136https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/694/A12?format=asciiOpticaldefaultJ/A+A/694/A12/2ndmax2Properties of the secondary maximum derived from the Gaussian process fitsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintt2r? Timing of secondary maximum in the r banddtime.intervalfloatnullablee_t2r? Timing of secondary maximum in the r band errordstat.errordoublenullablet2i? Timing of secondary maximum in the i banddtime.intervalfloatnullablee_t2i? Timing of secondary maximum in the i band errordstat.errordoublenullableF2r? Integrated flux under the secondary maximum in the r band (1)phot.flux.density;em.opt.Rdoublenullablee_F2r? Integrated flux under the secondary maximum in the r band errorstat.errordoublenullableF2i? Integrated flux under the secondary maximum in the r band (1)phot.flux.density;em.opt.Idoublenullablee_F2i? Integrated flux under the secondary maximum in the r band errorstat.errordoublenullableRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainNameZTF name (ZTFNNaaaaaaa)meta.id;meta.mainchar