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Paper: |
Late-Phase Observations of a Super-Chandrasekhar SN Ia |
Volume: |
458, Galactic Archaeology: Near-Field Cosmology and the Formation of the Milky Way |
Page: |
49 |
Authors: |
Yamanaka, M.; Kawabata, K. S.; Maeda, K.; Tanaka, M.; Yoshida, M.; Hattori, T.; Nomoto, K.; Komatsu, T.; Okushima, T. |
Abstract: |
A super-Chandrasekhar (SC) supernova (SN) has an extremely high luminosity and
a slow decline rate of the light curve in the early-phase. We present late-phase
observations of a SC SN 2009dc. We find that optical luminosity at a year after
maximum is much fainter than that expected from its early luminosity.
We attempt to fit the analytic light curve model to the observations
using Arnett's rule. The model successfully explains the light curves
until 120 days. This suggests that the extremely high luminosity originates
from the 56Ni decay. We suggest that the late-phase
decline would be caused by the dust formation.
The existence of strong carbon features in early-phase spectra
would support this scenario. We also find the blend of [Ca II] and
[Ni II] in its
late-phase spectrum. This indicates that the calcium is distributed
in the inner layer as nickel and iron. We conclude that the mixing may
occur in inner-part of the ejecta. |
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