TY - JOUR
T1 - SN 2006aj associated with XRF 060218 at late phases
T2 - Nucleosynthesis signature of a neutron star-driven explosion
AU - Maeda, K.
AU - Kawabata, K.
AU - Tanaka, M.
AU - Nomoto, K.
AU - Tominaga, N.
AU - Hattori, T.
AU - Minezaki, T.
AU - Kuroda, T.
AU - Suzuki, T.
AU - Deng, J.
AU - Mazzali, P. A.
AU - Pian, E.
PY - 2007/3/20
Y1 - 2007/3/20
N2 - Optical spectroscopy and photometry of SN 2006aj have been performed with the Subaru telescope at t > 200 days after GRB 060218, the X-ray flash with which it was associated. Strong nebular emission lines with an expansion velocity of v ∼ 7300 km s-1 were detected. The peaked but relatively broad [O I] λλX6300, 6363 suggests the existence of ∼2 M⊙ of materials in which ∼1.3 M⊙ is oxygen. The core might be produced by a mildly asymmetric explosion. The spectra are unique among SNe Ic in (1) the absence of [Ca II] λλ7291, 7324 emission and (2) a strong emission feature at ∼7400 Å, which requires ∼0.05 M⊙ of newly synthesized 58Ni. Such a large amount of stable neutron-rich Ni strongly indicates the formation of a neutron star. The progenitor and the explosion energy are constrained to 18 M⊙ ≲ Mms ≲ 22 M⊙ and E ∼ (1-3) × 1051 ergs, respectively.
AB - Optical spectroscopy and photometry of SN 2006aj have been performed with the Subaru telescope at t > 200 days after GRB 060218, the X-ray flash with which it was associated. Strong nebular emission lines with an expansion velocity of v ∼ 7300 km s-1 were detected. The peaked but relatively broad [O I] λλX6300, 6363 suggests the existence of ∼2 M⊙ of materials in which ∼1.3 M⊙ is oxygen. The core might be produced by a mildly asymmetric explosion. The spectra are unique among SNe Ic in (1) the absence of [Ca II] λλ7291, 7324 emission and (2) a strong emission feature at ∼7400 Å, which requires ∼0.05 M⊙ of newly synthesized 58Ni. Such a large amount of stable neutron-rich Ni strongly indicates the formation of a neutron star. The progenitor and the explosion energy are constrained to 18 M⊙ ≲ Mms ≲ 22 M⊙ and E ∼ (1-3) × 1051 ergs, respectively.
KW - Gamma rays: bursts
KW - Nuclear reactions, nucleosynthesis, abundances
KW - Supernovae: general
KW - Supernovae: individual (SN 2006aj)
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U2 - 10.1086/513564
DO - 10.1086/513564
M3 - Article
AN - SCOPUS:34047198940
SN - 0004-637X
VL - 658
SP - L5-L8
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 II
ER -