Details

Autor(en) / Beteiligte

• Tomasella, L.
• Cappellaro, E.
• Fraser, M.
• Pumo, M. L.
• Pastorello, A.
• Pignata, G.
• Benetti, S.
• Bufano, F.
• Dennefeld, M.
• Harutyunyan, A.
• Iijima, T.
• Jerkstrand, A.
• Kankare, E.
• Kotak, R.
• Magill, L.
• Nascimbeni, V.
• Ochner, P.
• Siviero, A.
• Smartt, S.
• Sollerman, J.
• Stanishev, V.
• Taddia, F.
• Taubenberger, S.
• Turatto, M.
• Valenti, S.
• Wright, D. E.
• Zampieri, L.

Titel

Comparison of progenitor mass estimates for the Type IIP SN 2012A

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2013, Vol.434 (2), p.1636-1657

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2013

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We present the one-year long observing campaign of SN 2012A which exploded in the nearby (9.8 Mpc) irregular galaxy NGC 3239. The photometric evolution is that of a normal Type IIP supernova, but the plateau is shorter and the luminosity not as constant as in other supernovae of this type. The absolute maximum magnitude, with M B = −16.23 ± 0.16 mag, is close to the average for SN IIP. Thanks also to the strong UV flux in the early phase, SN 2012A reached a peak luminosity of about 2 × 1042 erg s−1, which is brighter than those of other SNe with a similar 56Ni mass. The latter was estimated from the luminosity in the exponential tail of the light curve and found to be M(56Ni) = 0.011 ± 0.004 M, which is intermediate between standard and faint SN IIP. The spectral evolution of SN 2012A is also typical of SN IIP, from the early spectra dominated by a blue continuum and very broad (∼104 km s−1) Balmer lines, to the late-photospheric spectra characterized by prominent P-Cygni features of metal lines (Fe ii, Sc ii, Ba ii, Ti ii, Ca ii, Na i D). The photospheric velocity is moderately low, ∼3 × 103 km s−1 at 50 d, for the low optical depth metal lines. The nebular spectrum obtained 394 d after the shock breakout shows the typical features of SNe IIP and the strength of the [O i] doublet suggests a progenitor of intermediate mass, similar to SN 2004et (∼15 M). A candidate progenitor for SN 2012A has been identified in deep, pre-explosion K ′-band Gemini North Near-InfraRed Imager and Spectrometer images, and found to be consistent with a star with a bolometric magnitude −7.08 ± 0.36 (log L/L = 4.73 ± 0.14 dex). The magnitude of the recovered progenitor in archival images points towards a moderate-mass star as the precursor of SN 2012A. The explosion parameters and progenitor mass were also estimated by means of a hydrodynamical model, fitting the bolometric light curve, the velocity and the temperature evolution. We found a best fit for a kinetic energy of 0.48 foe, an initial radius of 1.8 × 1013 cm and ejecta mass of 12.5 M. Even including the mass for the compact remnant, this appears fully consistent with the direct measurements given above.