Details

Autor(en) / Beteiligte

• Bufano, F.
• Pignata, G.
• Bersten, M.
• Mazzali, P. A.
• Ryder, S. D.
• Margutti, R.
• Milisavljevic, D.
• Morelli, L.
• Benetti, S.
• Cappellaro, E.
• Gonzalez-Gaitan, S.
• Romero-Cañizales, C.
• Stritzinger, M.
• Walker, E. S.
• Anderson, J. P.
• Contreras, C.
• de Jaeger, T.
• Förster, F.
• Gutierrez, C.
• Hamuy, M.
• Hsiao, E.
• Morrell, N.
• Olivares E., F.
• Paillas, E.
• Parker, S.
• Pian, E.
• Pickering, T. E.
• Sanders, N.
• Stockdale, C.
• Turatto, M.
• Valenti, S.
• Fesen, R. A.
• Maza, J.
• Nomoto, K.
• Phillips, M. M.
• Soderberg, A.

Titel

SN 2011hs: a fast and faint Type IIb supernova from a supergiant progenitor

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2014-04, Vol.439 (2), p.1807-1828

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Observations spanning a large wavelength range, from X-ray to radio, of the Type IIb supernova (SN) 2011hs are presented, covering its evolution during the first year after explosion. The optical light curve presents a narrower shape and a fainter luminosity at peak than previously observed for Type IIb SNe. High expansion velocities are measured from the broad absorption H i and He i lines. From the comparison of the bolometric light curve and the time evolution of the photospheric velocities with hydrodynamical models, we found that SN 2011hs is consistent with the explosion of a 3-4 M He-core progenitor star, corresponding to a main-sequence mass of 12-15 M, that ejected a mass of 56Ni of about 0.04 M, with an energy of E = 8.5 × 1050 ERG. Such a low-mass progenitor scenario is in full agreement with the modelling of the nebular spectrum taken at ∼215 d from maximum. From the modelling of the adiabatic cooling phase, we infer a progenitor radius of 500-600 R, clearly pointing to an extended progenitor star. The radio light curve of SN 2011hs yields a peak luminosity similar to that of SN 1993J, but with a higher mass-loss rate and a wind density possibly more similar to that of SN 2001ig. Although no significant deviations from a smooth decline have been found in the radio light curves, we cannot rule out the presence of a binary companion star.