title: No signature of ejecta interaction with a stellar companion in three type Ia supernovae.
abstract: Type Ia supernovae are thought to be the result of a thermonuclear runaway in carbon/oxygen white dwarfs, but it is uncertain whether the explosion is triggered by accretion from a non-degenerate companion star or by a merger with another white dwarf. Observations of a supernova immediately following the explosion provide unique information on the distribution of ejected material and the progenitor system. Models predict that the interaction of supernova ejecta with a companion star or circumstellar debris lead to a sudden brightening lasting from hours to days. Here we present data for three supernovae that are likely to be type Ia observed during the Kepler mission with a time resolution of 30 minutes. We find no signatures of the supernova ejecta interacting with nearby companions. The lack of observable interaction signatures is consistent with the idea that these three supernovae resulted from the merger of binary white dwarfs or other compact stars such as helium stars.
authors.affiliation: Astronomy Department, University of Maryland, College Park, Maryland 20742-2421, USA.
authors.forename: Rob P
authors.initials: RP
authors.lastname: Olling
authors.affiliation: Astronomy Department, University of Maryland, College Park, Maryland 20742-2421, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Mushotzky
authors.affiliation: Astronomy Department, University of Maryland, College Park, Maryland 20742-2421, USA.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Shaya
authors.affiliation: Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, Maryland 21218, USA.
authors.forename: Armin
authors.initials: A
authors.lastname: Rest
authors.affiliation: Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, USA.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Garnavich
authors.affiliation: 1] Mt Stromlo Observatory, The Australian National University, via Cotter Road, Weston Creek, Australian Capital Territory 2611, Australia [2] Department of Astronomy, University of California, Berkeley, California 94720-3411, USA.
authors.forename: Brad E
authors.initials: BE
authors.lastname: Tucker
authors.affiliation: 1] Department of Astronomy, University of California, Berkeley, California 94720-3411, USA [2] Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Kasen
authors.affiliation: Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena, Chile.
authors.forename: Steve
authors.initials: S
authors.lastname: Margheim
authors.affiliation: Department of Astronomy, University of California, Berkeley, California 94720-3411, USA.
authors.forename: Alexei V
authors.initials: AV
authors.lastname: Filippenko