Details

Autor(en) / Beteiligte

• Jerkstrand, A.
• Smartt, S. J.
• Inserra, C.
• Nicholl, M.
• Chen, T.-W.
• Krühler, T.
• Sollerman, J.
• Taubenberger, S.
• Gal-Yam, A.
• Kankare, E.
• Maguire, K.
• Fraser, M.
• Valenti, S.
• Sullivan, M.
• Cartier, R.
• Young, D. R.

Titel

LONG-DURATION SUPERLUMINOUS SUPERNOVAE AT LATE TIMES

Ist Teil von

• The Astrophysical journal, 2017-01, Vol.835 (1), p.13

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2017

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• ABSTRACT Nebular-phase observations and spectral models of Type Ic superluminous supernovae (SLSNe) are presented. LSQ14an and SN 2015bn both display late-time spectra similar to galaxy-subtracted spectra of SN 2007bi, and the class shows strong similarity with broad-lined SNe Ic such as SN 1998bw. Near-infrared observations of SN 2015bn show a strong Ca ii triplet, O i 9263, O i 1.13 m, and Mg i 1.50 m, but no distinct He, Si, or S emission. The high Ca ii NIR/[Ca ii] 7291, 7323 ratio of ∼2 indicates a high electron density of cm−3. Spectral models of oxygen-zone emission are investigated to put constraints on the emitting region. Models require M to produce enough [O i] 6300, 6364 luminosity, irrespective of the powering situation and the density. The high oxygen-zone mass, supported by high estimated magnesium masses, points to explosions of massive CO cores, requiring . Collisions of pair-instability pulsations do not provide enough mass to account for the emission. [O ii] and [O iii] lines emerge naturally in many models, which strengthens the identification of broad [O ii] 7320, 7330, [O iii] 4363, and [O iii] 4959, 5007 in some spectra. A small filling factor for the O/Mg zone is needed to produce enough luminosity in Mg i] 4571, Mg i 1.504 m, and O i recombination lines, which shows that the ejecta is clumped. We review the constraints from the nebular spectral modeling in the context of the various scenarios proposed for SLSNe.