Details

Autor(en) / Beteiligte

• Chornock, Ryan
• Filippenko, Alexei V.
• Branch, David
• Foley, Ryan J.
• Jha, Saurabh
• Li, Weidong

Titel

Spectropolarimetry of the Peculiar Type Ia Supernova 2005hk

Ist Teil von

• Publications of the Astronomical Society of the Pacific, 2006-05, Vol.118 (843), p.722-732

Ort / Verlag

Chicago, IL: The University of Chicago Press

Erscheinungsjahr

2006

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We present Keck spectropolarimetry of the unusual Type Ia supernova (SN Ia) 2005hk several days before maximum light. An analysis of the high signal‐to‐noise ratio total‐flux spectrum shows the object’s extreme similarity to the peculiar SN 2002cx. SN 2005hk has an optical spectrum dominated by Feiiilines and only weak lines of intermediate‐mass elements, unlike a normal SN Ia at this epoch. The photospheric velocity measured from the minima of strong absorption lines is very low for an SN Ia (∼6000 km s−1), solidifying the connection to SN 2002cx. The spectrum‐synthesis code SYNOW was used to identify the presence of iron‐peak elements, intermediate‐mass elements, and possibly unburned carbon at similar velocities in the outer ejecta of SN 2005hk. Many weak spectral features remain unidentified. The spectropolarimetry shows a low level of continuum polarization (∼0.4%) after correction for the interstellar component, and only a weak Feiiiline feature is detected. The level of continuum polarization is normal for an SN Ia, implying that the unusual features of SN 2005hk cannot be readily explained by large asymmetries.