(Proposal ID) S11B-049

(PI) Tanaka, Masaomi

(Proposal Title)
Revealing 3D Structure of Core-Collapse Supernovae

(Abstract)
We propose Target of Opportunity (ToO) spectropolarimetric observations of 
stripped-envelope core-collapse supernovae (SNe) and SNe associated with gamma-
ray bursts (GRB-SNe, a special class of stripped-envelope SNe) to study their 
3D explosion geometry. Probing asphericity of stripped-envelope SNe gives 
crucial constraints on the explosion mechanism of SNe, which is one of the 
most important, unsolved questions in the modern astronomy. By obtaining high-
quality, multi-epoch spectropolarimetric data, we derive a typical 3D 
distribution of various elements in the SN ejecta. The number of 
spectropolarimetric observations of stripped-envelope SNe so far is too 
small to study common properties and diversity among stripped-envelope SNe. 
We aim to double the number of multi-epoch spectropolarimetric samples of 
stripped-envelope SNe. The number of observable stripped-envelope SNe 
discovered with magnitude sufficiently bright enough for spectropolarimetry 
is expected to be ~ 2 per half a year and they are bright enough only for 
about 20 days. Thus, we need ToO observation.