Searching for Imprints of Circumstellar Material in the Ultraviolet Spectra of Type Ia Supernovae

Beaudoin, Aaron T.; Foley, Ryan J.

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Description

Title

Searching for Imprints of Circumstellar Material in the Ultraviolet Spectra of Type Ia Supernovae

Author(s)

• Beaudoin, Aaron T.
• Foley, Ryan J.

Contributor(s)

Foley, Ryan

Issue Date

2015-05

Keyword(s)

• Astronomy
• Stellar
• Astrophysics
• Supernovae
• sn2011fe
• sn2014J

Abstract

Type Ia supernovae (SNe Ia), having large and standard luminosities, are our primary dark energy probe. Although we believe that SNe Ia are produced by white dwarfs (WDs) in binary systems, the type of companion star is still unclear. Using a SN as a backlight, we can probe the gas along the line-of-sight to a SN Ia, including possible circumstellar gas from the companion star. For a handful of SNe Ia, repeated measurements of the narrow Na D doublet have shown variable absorption that we interpret as the recombination of circumstellar Na atoms after being ionized by the initial UV SN flash. This is perhaps the best evidence that at least some SNe Ia have a main-sequence or red-giant companion. Using Hubble Space Telescope ultraviolet spectroscopy, we probe several additional species with varying ionization potentials for 8 SNe Ia. Since these features have different ionization potentials from species seen in the optical, they probe new physical regions of the circumstellar system. Although these features can potentially reveal previously hidden circumstellar gas, we do not detect any variable features in our best examples, indicating that these systems had no circumstellar gas or that the gas was particularly distant.

Type of Resource

• text
• image

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http://hdl.handle.net/2142/75951

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Copyright 2015 is held by the authors.

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