J/ApJ/787/29ivo://CDS.VizieR/J/ApJ/787/29doi:10.26093/cds/vizier.17870029CDSBrown P.J.Kuin P.Scalzo R.Smitka M.T.De Pasquale M.Holland S.,Krisciunas K.Milne P.Wang L.2017-09-04T08:04:38Z2017-07-13T15:47:23ZCDS support team

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

cds-question@unistra.frsupernovaeultraviolet-photometryAmong Type Ia supernovae (SNe Ia), a class of overluminous objects exist whose ejecta mass is inferred to be larger than the canonical Chandrasekhar mass. We present and discuss the UV/optical photometric light curves, colors, absolute magnitudes, and spectra of three candidate Super-Chandrasekhar mass SNe - 2009dc, 2011aa, and 2012dn - observed with the Swift Ultraviolet/Optical Telescope. The light curves are at the broad end for SNe Ia, with the light curves of SN 2011aa being among the broadest ever observed. We find all three to have very blue colors which may provide a means of excluding these overluminous SNe from cosmological analysis, though there is some overlap with the bluest of "normal" SNe Ia. All three are overluminous in their UV absolute magnitudes compared to normal and broad SNe Ia, but SNe 2011aa and 2012dn are not optically overluminous compared to normal SNe Ia. The integrated luminosity curves of SNe 2011aa and 2012dn in the UVOT range (1600-6000 {AA}) are only half as bright as SN 2009dc, implying a smaller ^56^Ni yield. While it is not enough to strongly affect the bolometric flux, the early time mid-UV flux makes a significant contribution at early times. The strong spectral features in the mid-UV spectra of SNe 2009dc and 2012dn suggest a higher temperature and lower opacity to be the cause of the UV excess rather than a hot, smooth blackbody from shock interaction. Further work is needed to determine the ejecta and ^56^Ni masses of SNe 2011aa and 2012dn and to fully explain their high UV luminosities.2014ApJ...787...29Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/787/29CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/339 : Swift/UVOT Serendipitous Source Catalog (Yershov, 2015)J/AJ/137/4517 : UVOT light curves of supernovae (Brown+, 2009)J/ApJ/721/1608 : Absolute UV magnitudes of type Ia SNe (Brown+, 2010)J/MNRAS/410/585 : SN 2009dc BVRI light curves (Silverman+, 2011)J/ApJ/749/18 : Swift/UVOT observations of 12 nearby SN-Ia (Brown+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/787/29https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/787/29http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/787/29https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/787/29https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/787/29http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/787/29GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/787/29/stars (List of studied supernovae)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/787/29/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/787/29/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/787/29/stars?GETtext/xml+votable180.050000true237.800525.70777780.0055555555555555566/8072 8667 48302https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/787/29?format=asciiUVdefaultJ/ApJ/787/29/table1UVOT photometryrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSNSupernova identifier (SN YYYYaa in Simbad)meta.id;meta.maincharFilterSwift/UVOT filter used in the observationinstr.setup;obscharMJDModified Julian Date of observationdtime.epochdoublemag? Observed magnitude in Filtermagphot.magfloatnullablee_mag? Error in magmagstat.error;phot.magfloatnullableCR? Count ratect/sphot.count;em.X-rayfloatnullablee_CR? Error in CRct/sstat.errorfloatnullableJ/ApJ/787/29/starsList of studied supernovaeSNSupernova identifiermeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Simbad Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Simbad Declination (J2000)pos.eq.dec;meta.mainLCLight curvesmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar