J/ApJ/924/35ivo://CDS.VizieR/J/ApJ/924/35doi:10.26093/cds/vizier.19240035CDSLi L.Zhang J.Dai B.Li W.Wang X.Zhai Q.Bai J.2023-10-03T13:06:40Z2023-08-28T09:45:40ZCDS support team

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

cds-question@unistra.frsupernovaevisible-astronomyspectroscopyWe present optical and ultraviolet (UV) observations of a luminous type Ia supernova (SN Ia) SN 2015bq characterized by early flux excess. This SN reaches a B-band absolute magnitude at M_B_=-19.68+/-0.41mag and a peak bolometric luminosity at L=(1.75+/-0.37)x10^43^erg/s, with a relatively small post-maximum decline rate [{Delta}m_15_(B)=0.82+/-0.05mag]. The flux excess observed in the light curves of SN 2015bq a few days after the explosion, especially seen in the UV bands, might be due to the radioactive decay of ^56^Ni mixed into the surface. The radiation from the decay of the surface ^56^Ni heats the outer layer of this SN. It produces blue U-B color followed by monotonically reddening in the early phase, dominated iron-group lines, and weak intermediate-mass element absorption features in the early spectra. The scenario of enhanced ^56^Ni in the surface is consistent with a large amount of ^56^Ni (M_56Ni_=0.97+/-0.20M_{sun}_) synthesized during the explosion. The properties of SN 2015bq are found to locate between SN 1991T and SN 1999aa, suggesting the latter two subclasses of SNe Ia may have a common origin.2022ApJ...924...35Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/924/35CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/AJ/131/527 : UBVRI light curves of 44 type Ia supernovae (Jha+, 2006)J/ApJ/645/488 : SN type Ia luminosities (Wang+, 2006)J/ApJ/700/331 : Light curves of type Ia supernovae (CfA3) (Hicken+, 2009)J/ApJ/699/L139 : Spectral parameters of SNe Ia (Wang+, 2009)J/AJ/143/126 : Spectroscopy of 462 nearby Type Ia supernovae (Blondin+, 2012)J/ApJ/753/22 : Swift/UVOT observations of SN 2011fe (Brown+, 2012)J/A+A/554/A27 : 2011fe spectrophotometric time series (Pereira+, 2013)J/AJ/148/1 : Optical and ultraviolet photometry of SN 2012fr (Zhang+, 2014)J/ApJ/813/30 : UV-Optical light curves of the SNIa iPTF14bdn (Smitka+, 2015)J/ApJS/220/20 : Si and Ca high-velocity features in SNe Ia (Zhao+, 2015)J/AJ/151/125 : Optical and UV photometry of SN 2013dy (Zhai+, 2016)J/MNRAS/491/2902 : Sub-Chandrasekhar progenitors for Type Ia SNe (Flors+, 2020)J/A+A/634/A37 : TURTLS Light curves of ^56^Ni distributions (Magee+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/924/35https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/924/35http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/924/35https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/924/35https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/924/35http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/924/35GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/924/35/tablea4Spectroscopic observation journal of SN 2015bqrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateDate of observation (UT)time.epochnullableMJD[57071.9/57164.7] Modified Julian Datedtime.epochdoubleEpoch[-12.19/80.55] Epoch; referring to the peak of B band on March 03.12 2015, JD2457084.62dtime.epochfloatRes[18/49] Resolution in {AA}/pixelnm/pixpos.angResolutionfloatlam1[3500/3800] Wavelength upper range in {AA}0.1nmem.wl;stat.maxintlam2[8700/9100] Wavelength lower range in {AA}0.1nmem.wl;stat.minintExp[1415/3000] Exposure timestime.duration;obs.exposureintAirMass[1/1.44] Air massobs.airMassfloatTelTelescope / Instrument (Lijiang 2.4m telescope (LJT) or Xing-Long 2.16m telescope (XLT))instrcharFileNameName of the ASCII file in subdirectory "sp"; column added by CDSmeta.id;meta.filecharspInteractive spectrum plotmeta.ref.urlchar