Multiepoch Spectropolarimetry of SN 2011fe

Peter A. Milne, George G Williams, Amber Porter, Paul S. Smith, Nathan Smith, Mark D. Leising, Buell Tomasson Jannuzi, E. M. Green

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

We present multiple spectropolarimetric observations of the nearby Type Ia supernova (SN) 2011fe in M101, obtained before, during, and after the time of maximum apparent visual brightness. The excellent time coverage of our spectropolarimetry has allowed better monitoring of the evolution of polarization features than is typical, which has allowed us new insight into the nature of normal SNe Ia. SN 2011fe exhibits time-dependent polarization in both the continuum and strong absorption lines. At early epochs, red wavelengths exhibit a degree of continuum polarization of up to 0.4%, likely indicative of a mild asymmetry in the electron-scattering photosphere. This behavior is more common in subluminous SNe Ia than in normal events, such as SN 2011fe. The degree of polarization across a collection of absorption lines varies dramatically from epoch to epoch. During the earliest epoch, a λ4600-5000 Å complex of absorption lines shows enhanced polarization at a different position angle than the continuum. We explore the origin of these features, presenting a few possible interpretations, without arriving at a single favored ion. During two epochs near maximum, the dominant polarization feature is associated with the Si ii λ6355 Å absorption line. This is common for SNe Ia, but for SN 2011fe the polarization of this feature increases after maximum light, whereas for other SNe Ia, that polarization feature was strongest before maximum light.

Original languageEnglish (US)
Article number100
JournalAstrophysical Journal
Volume835
Issue number1
DOIs
StatePublished - Jan 20 2017

Fingerprint

supernovae
polarization
time measurement
continuums
photosphere
asymmetry
electron scattering
brightness
scattering
wavelength
electron
ion
monitoring
wavelengths
ions

Keywords

  • supernovae: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

Milne, P. A., Williams, G. G., Porter, A., Smith, P. S., Smith, N., Leising, M. D., ... Green, E. M. (2017). Multiepoch Spectropolarimetry of SN 2011fe. Astrophysical Journal, 835(1), [100]. https://doi.org/10.3847/1538-4357/835/1/100

Multiepoch Spectropolarimetry of SN 2011fe. / Milne, Peter A.; Williams, George G; Porter, Amber; Smith, Paul S.; Smith, Nathan; Leising, Mark D.; Jannuzi, Buell Tomasson; Green, E. M.

In: Astrophysical Journal, Vol. 835, No. 1, 100, 20.01.2017.

Research output: Contribution to journalArticle

Milne, Peter A. ; Williams, George G ; Porter, Amber ; Smith, Paul S. ; Smith, Nathan ; Leising, Mark D. ; Jannuzi, Buell Tomasson ; Green, E. M. / Multiepoch Spectropolarimetry of SN 2011fe. In: Astrophysical Journal. 2017 ; Vol. 835, No. 1.
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