BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Yossef Zenati (Johns Hopkins U.) DTSTART:20210311T143000Z DTEND:20210311T153000Z DTSTAMP:20260423T035731Z UID:CENTRA/32 DESCRIPTION:Title: The physical mechanism behind normal and peculiar SN Ia\nby Yossef Zen ati (Johns Hopkins U.) as part of CENTRA Seminar\n\n\nAbstract\nType Ia su pernovae (SNe) are thought to originate from the thermonuclear explosions of carbon-oxygen (CO) white dwarfs (WDs). The proposed progenitors of stan dard type Ia SNe have been studied for decades and can be\, generally\, di vided into explosions of CO WDs accreting material from stellar non-degene rate companions (single-degenerate\; SD models)\, and those arising from t he explosive interaction of two CO WDs (double-degenerate\; DD models). Ho wever\, current models for the progenitors of such SNe fail to reproduce t he diverse properties of the observed explosions\, nor do they explain the inferred rates and the characteristics of the observed populations of typ e Ia SNe and their expected progenitors. Here we show that the little-stud ied mergers of CO-WDs with hybrid Helium-CO (He-CO) WDs can provide for a significant fraction of the normal type Ia SNe. Here we use detailed therm onuclear-hydrodynamical and radiative-transfer models to show that a wide range of mergers of CO WDs with hybrid He-CO WDs can give rise to normal t ype Ia SNe. We find that such He-enriched mergers give rise to explosions for which the synthetic light-curves and spectra resemble those of observe d type Ia SNe\, and in particular\, they can produce a wide range of peak- luminosities\, MB(MR)~ 18.4 to 19.2 (~ 18.5 to 19:45)\, consistent with th ose observed for normal type Ia SNe. Moreover\, our population synthesis m odels show that\, together with the contribution from mergers of massive d ouble CO-WDs (producing the more luminous SNe)\, they can potentially repr oduce the full range of type Ia SNe\, their rate and delay-time distributi on.\n LOCATION:https://researchseminars.org/talk/CENTRA/32/ END:VEVENT END:VCALENDAR