Properties of Newly Formed Dust Grains in the Luminous Type IIn Supernova 2010jl

MAEDA; NOZAWA; SAHU; MINOWA; MOTOHARA; UENO ; FOLATELLI ; PYO ; KITAGAWA ; KAWABATA ; ANUPAMA ; KOZASA ; MORIYA ; YAMANAKA; NOMOTO; BERSTEN

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Londres; Año: 2013 vol. 776 p. 5 - 21

0004-637X

Supernovae (SNe) have been proposed to be the main production sites ofdust grains in the universe. However, our knowledge of theirimportance to dust production is limited by observationally poorconstraints on the nature and amount of dust particles produced byindividual SNe. In this paper, we present a spectrum covering opticalthrough near-Infrared (NIR) light of the luminous Type IIn supernova2010jl around one and a half years after the explosion. This uniquedata set reveals multiple signatures of newly formed dustparticles. The NIR portion of the spectrum provides a rare examplewhere thermal emission from newly formed hot dust grains is clearlydetected. We determine the main population of the dust species to becarbon grains at a temperature of ~1350-1450 K at this epoch. The massof the dust grains is derived to be ~(7.5-8.5) × 10^-4 Msun. Hydrogenemission lines show wavelength-dependent absorption, which provides agood estimate of the typical size of the newly formed dust grains(< 0.1 um, and most likely <~ 0.01 um). We believe the dust grainswere formed in a dense cooling shell as a result of a strongSN-circumstellar media (CSM) interaction. The dust grains occupy ~10%of the emitting volume, suggesting an inhomogeneous, clumpystructure. The average CSM density must be >~ 3 × 10^7 cm^-3,corresponding to a mass loss rate of >~ 0.02 Msun yr^-1 (for a mass losswind velocity of ~100 km s-1). This strongly supports a scenario inwhich SN 2010jl and probably other luminous SNe IIn are powered bystrong interactions within very dense CSM, perhaps created byLuminous-Blue-Variable-like eruptions within the last century beforethe explosion.