Three-Dimensional Explosion Geometry of Stripped-Envelope Core-Collapse Supernovae. I. Spectropolarimetric Observations
Abstract
We study the multi-dimensional geometry of supernova (SN) explosions by means of spectropolarimetric observations of stripped-envelope SNe, i.e., SNe without a H-rich layer. We perform spectropolarimetric observations of 2 stripped-envelope SNe, the Type Ib SN 2009jf and the Type Ic SN 2009mi. Both objects show non-zero polarization at the wavelength of the strong lines. They also show a loop in the Stokes Q-U diagram, which indicates a non-axisymmetric, three-dimensional ion distribution in the ejecta. We show that five out of six stripped-envelope SNe which have been observed spectropolarimetrically so far show such a loop. This implies that a three-dimensional geometry is common in stripped-envelope SNe. We find that stronger lines tend to show higher polarization. This effect is not related to the geometry, and must be corrected to compare the polarization of different lines or different objects. Even after the correction, however, there remains a dispersion of polarization degree among different objects. Such a dispersion might be caused by three-dimensional clumpy ion distributions viewed from different directions.
Keywords
Cite
@article{arxiv.1205.4111,
title = {Three-Dimensional Explosion Geometry of Stripped-Envelope Core-Collapse Supernovae. I. Spectropolarimetric Observations},
author = {Masaomi Tanaka and Koji S. Kawabata and Takashi Hattori and Paolo A. Mazzali and Kentaro Aoki and Masanori Iye and Keiichi Maeda and Ken'ichi Nomoto and Elena Pian and Toshiyuki Sasaki and Masayuki Yamanaka},
journal= {arXiv preprint arXiv:1205.4111},
year = {2015}
}
Comments
Accepted for publication in ApJ, 10 pages