Late-time spectroscopy of SN 2002cx: The prototype of a new subclass of Type Ia supernovae

Saurabh Jha, David Branch, Ryan Chornock, Ryan J. Foley, Weidong Li, Brandon J. Swift, Darrin Casebeer, Alexei V. Filippenko

Research output: Contribution to journalArticlepeer-review


We present Keck optical spectra of SN 2002cx, the most peculiar known Type Ia supernova (SN Ia), taken 227 and 277 days past maximum light. Astonishingly, the spectra are not dominated by the forbidden emission lines of iron that are a hallmark of thermonuclear SNe in the nebular phase. Instead, we identify numerous P Cygni profiles of Fe II at very low expansion velocities of ∼700 km s -1, which are without precedent in SNe Ia. We also report the tentative identification of low-velocity O I in these spectra, suggesting the presence of unbumed material near the center of the exploding white dwarf. SN 2002cx is the prototype of a new subclass of SNe Ia, with spectral characteristics that may be consistent with recent pure deflagration models of Chandrasekhar-mass thermonuclear SNe. These are distinct from the majority of SNe Ia, for which an alternative explosion mechanism, such as a delayed detonation, may be required.

Original languageEnglish (US)
Pages (from-to)189-196
Number of pages8
JournalAstronomical Journal
Issue number1
StatePublished - Jul 2006
Externally publishedYes


  • Supernovae: general
  • Supernovae: individual (SN 2002cx)

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Late-time spectroscopy of SN 2002cx: The prototype of a new subclass of Type Ia supernovae'. Together they form a unique fingerprint.

Cite this