Explaining the Early Excess Emission of the Type Ia Supernova 2018oh by the Interaction of the Ejecta with Disk-originated Matter

TY - JOUR

T1 - Explaining the Early Excess Emission of the Type Ia Supernova 2018oh by the Interaction of the Ejecta with Disk-originated Matter

AU - Levanon, Naveh

AU - Soker, Noam

N1 - Publisher Copyright: © 2019. The American Astronomical Society. All rights reserved..

PY - 2019/2/10

Y1 - 2019/2/10

N2 - We explain the early excess emission of the Type Ia supernova 2018oh by an interaction of the supernova ejecta with disk-originated matter (DOM). Such DOM can form in the merger process of two white dwarfs in the double-degenerate scenario of Type Ia supernovae (SNe Ia). We find that an ejecta-DOM interaction can fit the early light curve of SN 2018oh better than an ejecta-companion interaction in the single-degenerate scenario. By composing the DOM from two components that were ejected in the merger process with two different velocities, we show that the ejecta-DOM interaction can account for the linear rise in the light curve, while the ejecta-companion interaction predicts too steep of a rise. In addition, the ejecta-DOM interaction does not predict the presence of hydrogen and helium lines in nebular spectra, and hence does not suffer from this major drawback of the ejecta-companion model. We consider the ejecta-DOM interaction to be the most likely explanation for the early excess emission in SN 2018oh. By that we show that the double-degenerate scenario can account for early excess emission in SNe Ia.

AB - We explain the early excess emission of the Type Ia supernova 2018oh by an interaction of the supernova ejecta with disk-originated matter (DOM). Such DOM can form in the merger process of two white dwarfs in the double-degenerate scenario of Type Ia supernovae (SNe Ia). We find that an ejecta-DOM interaction can fit the early light curve of SN 2018oh better than an ejecta-companion interaction in the single-degenerate scenario. By composing the DOM from two components that were ejected in the merger process with two different velocities, we show that the ejecta-DOM interaction can account for the linear rise in the light curve, while the ejecta-companion interaction predicts too steep of a rise. In addition, the ejecta-DOM interaction does not predict the presence of hydrogen and helium lines in nebular spectra, and hence does not suffer from this major drawback of the ejecta-companion model. We consider the ejecta-DOM interaction to be the most likely explanation for the early excess emission in SN 2018oh. By that we show that the double-degenerate scenario can account for early excess emission in SNe Ia.

KW - supernovae: general

KW - white dwarfs

UR - http://www.scopus.com/inward/record.url?scp=85062026154&partnerID=8YFLogxK

U2 - 10.3847/2041-8213/ab0285

DO - 10.3847/2041-8213/ab0285

M3 - 文章

AN - SCOPUS:85062026154

VL - 872

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 1

M1 - L7

ER -