On the nature of rapidly fading Type II supernovae
Number of Authors: 4
2016 (English)In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 455, no 1, 423-430 p.Article in journal (Refereed) Published
It has been suggested that Type II supernovae with rapidly fading light curves (a.k.a. Type IIL supernovae) are explosions of progenitors with low-mass hydrogen-rich envelopes which are of the order of 1M(circle dot.) We investigate light-curve properties of supernovae from such progenitors. We confirm that such progenitors lead to rapidly fading Type II supernovae. We find that the luminosity of supernovae from such progenitors with the canonical explosion energy of 10(51) erg and Ni-56 mass of 0.05 M-circle dot can increase temporarily shortly before all the hydrogen in the envelope recombines. As a result, a bump appears in their light curves. The bump appears because the heating from the nuclear decay of Ni-56 can keep the bottom of hydrogen-rich layers in the ejecta ionized, and thus the photosphere can stay there for a while. We find that the light-curve bump becomes less significant when we make explosion energy larger (greater than or similar to 2 x 10(51) erg), Ni-56 mass smaller (less than or similar to 0.01 M-circle dot), Ni-56 mixed in the ejecta, or the progenitor radius larger. Helium mixing in hydrogen-rich layers makes the light-curve decline rates large but does not help reducing the light-curve bump. Because the light-curve bump we found in our light-curve models has not been observed in rapidly fading Type II supernovae, they may be characterized by not only low-mass hydrogen-rich envelopes but also higher explosion energy, larger degrees of Ni-56 mixing, and/or larger progenitor radii than slowly fading Type II supernovae, so that the light-curve bump does not become significant.
Place, publisher, year, edition, pages
2016. Vol. 455, no 1, 423-430 p.
stars: evolution, stars: massive, stars: mass-loss, supernovae: general
IdentifiersURN: urn:nbn:se:su:diva-126780DOI: 10.1093/mnras/stv2336ISI: 000368005900055OAI: oai:DiVA.org:su-126780DiVA: diva2:944218