Spectropolarimetry of the Type Ia SN 2007sr Two Months After Maximum Light

TL;DR

This paper reports late-time spectropolarimetric observations of SN 2007sr, revealing strong line polarization in calcium features, suggesting asymmetries in the supernova ejecta at 63 days post-maximum.

Contribution

It provides new late-time spectropolarimetric data of a Type Ia supernova, highlighting polarization features associated with high velocity ejecta.

Findings

Strong line polarization in CaII features at late times

High velocity features may be linked to polarization behavior

SN 2007sr exhibits polarization patterns similar to some normal Type Ia SNe

Abstract

We present late time spectropolarimetric observations of SN 2007sr, obtained with the VLT telescope at ESO Paranal Observatory when the object was 63 days after maximum light. The late time spectrum displays strong line polarization in the CaII absorption features. SN 2007sr adds to the case of some normal Type Ia SNe that show high line polarization or repolarization at late times, a fact that might be connected with the presence of high velocity features at early times.