Optical and radio transients after collapse of super-Chandrasekhar white dwarf merger remnants. (arXiv:1812.06631v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Yu_Y/0/1/0/all/0/1">Yun-Wei Yu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_A/0/1/0/all/0/1">Aming Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_B/0/1/0/all/0/1">Bo Wang</a>
Super-Chandrasekhar remnants of double white dwarf mergers could sometimes
collapse into a rapidly rotating neutron star, accompanying with a mass
ejection of a few times $0.01M_{odot}$. Bright optical transient emission can
be produced by the ejecta due to heating by radioactivities and particularly by
energy injection from the neutron star. Since the merger remnants before
collapse resemble a star evolving from asymptotic giant branch phase to
planetary nebula phase, an intense dusty wind is considered to be driven about
several thousand years ago before the collapse and surround the remnant at
large radii. Therefore, the optical transient emission can be somewhat absorbed
and scattered by the dusty wind, which can suppress the peak emission and cause
a scattering plateau in optical light curves. Several years later, as the
ejecta finally catches up with the wind material, the shock interaction between
them can further give rise to a detectable radio transient emission on a
timescale of several ten days. Discovery of and observations to such
dust-affected optical transients and shock-driven radio transients can help to
explore the nature of super-Chandrasekhar merger remnants and as well as the
density and type ratios of double white dwarf systems, which is benefit for
assessing their gravitational wave contributions.
Super-Chandrasekhar remnants of double white dwarf mergers could sometimes
collapse into a rapidly rotating neutron star, accompanying with a mass
ejection of a few times $0.01M_{odot}$. Bright optical transient emission can
be produced by the ejecta due to heating by radioactivities and particularly by
energy injection from the neutron star. Since the merger remnants before
collapse resemble a star evolving from asymptotic giant branch phase to
planetary nebula phase, an intense dusty wind is considered to be driven about
several thousand years ago before the collapse and surround the remnant at
large radii. Therefore, the optical transient emission can be somewhat absorbed
and scattered by the dusty wind, which can suppress the peak emission and cause
a scattering plateau in optical light curves. Several years later, as the
ejecta finally catches up with the wind material, the shock interaction between
them can further give rise to a detectable radio transient emission on a
timescale of several ten days. Discovery of and observations to such
dust-affected optical transients and shock-driven radio transients can help to
explore the nature of super-Chandrasekhar merger remnants and as well as the
density and type ratios of double white dwarf systems, which is benefit for
assessing their gravitational wave contributions.
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