Formation and Evolution of Dust in Type IIb Supernova with Application to the Cassiopeia A Supernova Remnant - Astrophysics > Solar and Stellar AstrophysicsReport as inadecuate




Formation and Evolution of Dust in Type IIb Supernova with Application to the Cassiopeia A Supernova Remnant - Astrophysics > Solar and Stellar Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We investigate the formation of dust grains in the ejecta of a SN IIb andtheir evolution in the shocked gas in the SNR by considering the uniform andpower-law density structures for the CSM. Based on these calculations, we alsosimulate the time evolution of thermal emission from the shock-heated dust inthe SNR and compare the results with the observations of Cas A SNR. We findthat the total mass of dust formed in the SN IIb is as large as 0.167 M sun butthe average radius of dust is smaller than 0.01 mum and is significantlydifferent from those in SNe II-P with the massive H-envelope. In the explosionwith the small-mass H-envelope, the expanding He core undergoes littledeceleration, so that the gas density in the He core is too low for large-sizedgrains to form. In addition, the low-mass H-envelope of the SN IIb leads to theearly arrival of the reverse shock at the dust-forming region. If the CSM ismore or less spherical, therefore, the newly formed grains would be completelydestroyed in the relatively dense shocked gas for the CSM density of n H > 0.1cm^{-3}. However, the actual CSM is likely to be non-spherical, so that a partof grains could be ejected into the ISM without being shocked. We demonstratethat the time evolution of the SED by thermal dust emission is sensitive to theambient gas density and structure that affects the passage of the reverse shockinto the ejecta. Thus, the SED evolution well reflects the evolution of dustthrough erosion by sputtering and stochastic heating. For Cas A, we considerthe CSM produced by the steady mass loss of ~8x10^{-5} M sun-yr during thesupergiant phase. Then we find the infrared SED of Cas A is reasonablyreproduced by thermal emission from the newly formed dust of 0.08 M sun, whichconsists of 0.008 M sun shocked warm dust and 0.072 M sun unshocked cold dust.



Author: Takaya Nozawa, Takashi Kozasa, Nozomu Tominaga, Keiichi Maeda, Hideyuki Umeda, Ken'ichi Nomoto, Oliver Krause

Source: https://arxiv.org/



DOWNLOAD PDF




Related documents