TY - JOUR
T1 - Dust and the Type II-plateau Supernova 2004dj
AU - Meikle..[et al.], W.P.S.
AU - Kotak, R.
AU - Frarrah, D.
AU - Andersen, Anja C.
AU - Sollerman, Jesper Olof
PY - 2011/5/10
Y1 - 2011/5/10
N2 - We present mid-infrared (MIR) spectroscopy of a Type II-plateau supernova, SN2004dj, obtained with the Spitzer Space Telescope, spanning 106-1393days after explosion. MIR photometry plus optical/near-IR observations are also reported. An early-time MIR excess is attributed to emission from non-silicate dust formed within a cool dense shell (CDS). Most of the CDS dust condensed between 50days and 165days, reaching a mass of 0.3 × 10-5 M⊙. Throughout the observations, much of the longer wavelength (>10 μm) part of the continuum is explained as an IR echo from interstellar dust. The MIR excess strengthened at later times. We show that this was due to thermal emission from warm, non-silicate dust formed in the ejecta. Using optical/near-IR line profiles and the MIR continua, we show that the dust was distributed as a disk whose radius appeared to be shrinking slowly. The disk radius may correspond to a grain destruction zone caused by a reverse shock which also heated the dust. The dust-disk lay nearly face-on, had high opacities in the optical/near-IR regions, but remained optically thin in the MIR over much of the period studied. Assuming a uniform dust density, the ejecta dust mass by 996days was (0.5 ± 0.1) × 10-4 M ⊙ and exceeded 10-4 M⊙ by 1393days. For a dust density rising toward the center the limit is higher. Nevertheless, this study suggests that the amount of freshly synthesized dust in the SN2004dj ejecta is consistent with that found from previous studies and adds further weight to the claim that such events could not have been major contributors to the cosmic dust budget.
AB - We present mid-infrared (MIR) spectroscopy of a Type II-plateau supernova, SN2004dj, obtained with the Spitzer Space Telescope, spanning 106-1393days after explosion. MIR photometry plus optical/near-IR observations are also reported. An early-time MIR excess is attributed to emission from non-silicate dust formed within a cool dense shell (CDS). Most of the CDS dust condensed between 50days and 165days, reaching a mass of 0.3 × 10-5 M⊙. Throughout the observations, much of the longer wavelength (>10 μm) part of the continuum is explained as an IR echo from interstellar dust. The MIR excess strengthened at later times. We show that this was due to thermal emission from warm, non-silicate dust formed in the ejecta. Using optical/near-IR line profiles and the MIR continua, we show that the dust was distributed as a disk whose radius appeared to be shrinking slowly. The disk radius may correspond to a grain destruction zone caused by a reverse shock which also heated the dust. The dust-disk lay nearly face-on, had high opacities in the optical/near-IR regions, but remained optically thin in the MIR over much of the period studied. Assuming a uniform dust density, the ejecta dust mass by 996days was (0.5 ± 0.1) × 10-4 M ⊙ and exceeded 10-4 M⊙ by 1393days. For a dust density rising toward the center the limit is higher. Nevertheless, this study suggests that the amount of freshly synthesized dust in the SN2004dj ejecta is consistent with that found from previous studies and adds further weight to the claim that such events could not have been major contributors to the cosmic dust budget.
U2 - 10.1088/0004-637X/732/2/109
DO - 10.1088/0004-637X/732/2/109
M3 - Journal article
SN - 0004-637X
VL - 732
SP - 109
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
ER -