Tidal disruptions of main sequence stars — II. Simulation methodology and stellar mass dependence of the character of full tidal disruptions. (arXiv:2001.03502v3 [astro-ph.HE] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Ryu_T/0/1/0/all/0/1">Taeho Ryu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Krolik_J/0/1/0/all/0/1">Julian Krolik</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piran_T/0/1/0/all/0/1">Tsvi Piran</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Noble_S/0/1/0/all/0/1">Scott C. Noble</a>
This is the second in a series of papers presenting the results of fully
general relativistic simulations of stellar tidal disruptions in which the
stars’ initial states are realistic main-sequence models. In the first paper
(Paper I), we gave an overview of this program and discussed the principal
observational implications of our work. Here we describe our calculational
method and provide details about the outcomes of full disruptions, focusing on
the stellar mass dependence of the outcomes for a black hole of mass
$10^{6}rm{M}_{odot}$. We consider eight different stellar masses, from
$0.15~{rm M}_odot$ to $10~{rm M}_odot$. We find that, relative to the
traditional order-of-magnitude estimate $r_{rm t}$, the physical tidal radius
of low-mass stars ($M_{star} lesssim 0.7~ {rm M}_odot$) is larger by tens
of percent, while for high-mass stars ($M_{star} gtrsim1~ {rm M}_odot$) it
is smaller by a factor 2–2.5. The traditional estimate of the range of
energies found in the debris is $approx 1.4times$ too large for low-mass
stars, but is a factor $sim 2$ too small for high-mass stars; in addition, the
energy distribution for high-mass stars has significant wings. For all stars
undergoing tidal encounters, we find that mass-loss continues for many stellar
vibration times because the black hole’s tidal gravity competes with the
instantaneous stellar gravity at the star’s surface until the star has reached
a distance from the black hole $sim O(10)r_{rm t}$.
This is the second in a series of papers presenting the results of fully
general relativistic simulations of stellar tidal disruptions in which the
stars’ initial states are realistic main-sequence models. In the first paper
(Paper I), we gave an overview of this program and discussed the principal
observational implications of our work. Here we describe our calculational
method and provide details about the outcomes of full disruptions, focusing on
the stellar mass dependence of the outcomes for a black hole of mass
$10^{6}rm{M}_{odot}$. We consider eight different stellar masses, from
$0.15~{rm M}_odot$ to $10~{rm M}_odot$. We find that, relative to the
traditional order-of-magnitude estimate $r_{rm t}$, the physical tidal radius
of low-mass stars ($M_{star} lesssim 0.7~ {rm M}_odot$) is larger by tens
of percent, while for high-mass stars ($M_{star} gtrsim1~ {rm M}_odot$) it
is smaller by a factor 2–2.5. The traditional estimate of the range of
energies found in the debris is $approx 1.4times$ too large for low-mass
stars, but is a factor $sim 2$ too small for high-mass stars; in addition, the
energy distribution for high-mass stars has significant wings. For all stars
undergoing tidal encounters, we find that mass-loss continues for many stellar
vibration times because the black hole’s tidal gravity competes with the
instantaneous stellar gravity at the star’s surface until the star has reached
a distance from the black hole $sim O(10)r_{rm t}$.
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