Three-dimensional simulations of the interaction between Type Ia supernova ejecta and their main sequence companions

Abstract

Context. The identity of the progenitor systems of Type Ia supernovae (SNe Ia) is still uncertain. In the single-degenerate scenario, the interaction between the supernova blast wave and the outer layers of a main sequence companion star strips off hydrogen-rich material which is then mixed into the ejecta. Strong contamination of the supernova ejecta with stripped material could lead to a conflict with observations of SNe Ia. This constrains the single-degenerate progenitor model. Aims. In this work, our previous simulations based on simplified progenitor donor stars have been updated by adopting more realistic progenitor-system models that result from fully detailed, state-of-the-art binary evolution calculations. Methods. We use Eggleton's stellar evolution code including the optically thick accretion wind model and taking into account the possibility of the effects of accretion disk instabilities to obtain realistic models of companion stars for different progenitor systems. The impact of the supernova blast wave on these companion stars is followed in three-dimensional hydrodynamic simulations employing the smoothed particle hydrodynamics code GADGET3. Results. For a suite of main sequence companions, we find that the mass of the material stripped from the companions range from 0.11 M to 0.18 M . The kick velocity delivered by the impact is between 51 km s −1 and 105 km s −1 . We find that the stripped mass and kick velocity depend on the ratio of the orbital separation to the radius of a companion, a f /R. They can be fitted in good approximation by a power law for a given companion model. However, we do not find a single power law relation holding for different companion models. This implies that the structure of the companion star is also important for the amount of stripped material. Conclusions. With more realistic companion star models than those employed in previous studies, our simulations show that the hydrogen masses stripped from companions are inconsistent with the best observational limits ( 0.01 M ) derived from SN Ia nebular spectra. However, a rigorous forward modeling from the results of impact simulations with radiation transfer is required to reliably predict observable signatures of the stripped hydrogen and to conclusively assess the viability of the considered SN Ia progenitor scenario.

Constraining the progenitor of the Type Ia Supernova SN 2012cg

“…Most interestingly, Maguire et al (2016) constrained the removed H-mass in SN 2012cg to be 0.005 − 0.008 M ⊙ , which is much less massive than the removed H-rich mass predicted from recent hydrodynamical simulations for the MS and RG donor scenario ( 0.1 M ⊙ with a typical velocity of 1000 km s −1 , e.g., Liu et al 2012Liu et al , 2013aPan, Ricker & Taam 2012). This poses a serious challenge to the MS/RG donor binary system as the progenitor of SN 2012cg.…”

“…However, as discussed by Maguire et al (2016), the observed flux at the position of H α was converted to the mass with one-dimensional models by Mattila et al (2005), and Lundqvist et al (2013) who performed spectral synthesis modelling based on the earliest two-dimensional impact simulation of Marietta, Burrows & Fryxell (2000), which might lead to some uncertainties of the results. To place a more stringent constraint on the upper-limit mass for non-detection of swept-up H in latetime spectra of SNe Ia, future multi-dimensional radiative transfer modelling with ejecta structures obtained from updated threedimensional impact simulations such as those of Liu et al (2012) and Pan, Ricker & Taam (2012) is still needed.…”

“…6, the surviving MS star would be expected to become more luminous than the SN itself around 2 000 days after the maximum B-band brightness. Also, this surviving star is predicted to move with a peculiar spatial velocity that is dominated by its pre-explosion orbital velocity and possibly show some peculiar abundances signatures due to enrichment by heavy elements from SN ejecta (Liu et al 2012;Pan, Ricker & Taam 2012). However, no surviving star is expected in the DD scenario.…”

“…Even for the same progenitor scenario, it was found that fitting parameters are also dependent on the details of the structure of the companion star due to the history of mass transfer (Liu et al 2012). For example, for the MS donor scenario, the fitting parameters could be slightly different if the detailed structures of the MS companion star are somewhat different (see Table 3 of Liu et al 2012). However, we expect that the peak of removed H-rich mass in Fig.…”

Evolution towards and beyond accretion-induced collapse of massive white dwarfs and formation of millisecond pulsars

“…These models can be used in future work to study the impact of the SN Ia explosion on the donor star and thus help predict the expected properties of former companions stars when searching for these in SN Ia remnants (see e.g. Marietta et al 2000;Di Stefano & Kilic 2012;Liu et al 2012;Pan et al 2010Pan et al , 2012Pan et al , 2013. These authors demonstrated that whereas helium star donors may only lose about 5% of their mass, and main-sequence star donors lose some 10-20%, giant star donors may lose most of their envelope because of the SN impact.…”