(Proposal ID) S11B-046

(PI) Maeda, Keiichi

(Proposal Title)
Type Ia Supernova Explosion Mechanism Through NIR Spectroscopy

(Abstract)
We propose to take J & H band spectra and photometry for Type Ia Supernova 
(SN Ia) 2011ae at ~ 300 days after the explosion, using IRCS and LGS-AO. SN Ia 
2011ae is exceptionally nearby for a SN Ia (27 Mpc), and intensive follow up 
has been performed in the early phase. Late-time spectra can be used to probe 
distributions of different elements/isotopes synthesized at the explosion, 
thus providing so far the only tool to tackle how the thermonuclear ignition 
starts. The investigation has been mostly restricted to optical wavelength, 
indicating the offset asymmetry. NIR late-time spectroscopy is more 
challenging, but provides even more detailed information. In the wavelength 
range near [Fe II] J & H, there are virtually no contamination from other ions 
and other levels, allowing the detailed line profiles being investigated. 
Also, the NIR lines are more sensitive to the region processed by the 
thermonuclear sparks at the very beginning than in optical. The proposed 
observation will allow to investigate a relation between the detailed 
explosion mechanism and the standard-candle-natures of SNe Ia, with 
qualitatively different information from those previously obtained by 
conventional SN observations.