Tidal disruptions of main sequence stars — III. Stellar mass dependence of the character of partial disruptions. (arXiv:2001.03503v3 [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>
In this paper, the third in this series, we continue our study of tidal
disruption events of main-sequence stars by a non-spinning
$10^{6}~rm{M}_odot$ supermassive black hole. Here we focus on the stellar
mass dependence of the outcomes of partial disruptions. As the encounter
becomes weaker, the debris mass is increasingly concentrated near the outer
edges of the energy distribution. As a result, the mass fallback rate can
deviate substantially from a $t^{-5/3}$ power-law, becoming more like a single
peak with a tail declining as $t^{-p}$ with $psimeq2-5$. Surviving remnants
are spun-up in the prograde direction and are hotter than main sequence stars
of the same mass. Their specific orbital energy is $simeq10^{-3}times$ that
of the debris, but of either sign with respect to the black hole potential,
while their specific angular momentum is close to that of the original star.
Even for strong encounters, remnants have speeds at infinity relative to the
black hole potential $lesssim 300$ km s$^{-1}$, so they are unable to travel
far out into the galactic bulge. The remnants most deeply bound to the black
hole go through a second tidal disruption event upon their first return to
pericenter; if they have not thermally relaxed, they will be completely
disrupted.
In this paper, the third in this series, we continue our study of tidal
disruption events of main-sequence stars by a non-spinning
$10^{6}~rm{M}_odot$ supermassive black hole. Here we focus on the stellar
mass dependence of the outcomes of partial disruptions. As the encounter
becomes weaker, the debris mass is increasingly concentrated near the outer
edges of the energy distribution. As a result, the mass fallback rate can
deviate substantially from a $t^{-5/3}$ power-law, becoming more like a single
peak with a tail declining as $t^{-p}$ with $psimeq2-5$. Surviving remnants
are spun-up in the prograde direction and are hotter than main sequence stars
of the same mass. Their specific orbital energy is $simeq10^{-3}times$ that
of the debris, but of either sign with respect to the black hole potential,
while their specific angular momentum is close to that of the original star.
Even for strong encounters, remnants have speeds at infinity relative to the
black hole potential $lesssim 300$ km s$^{-1}$, so they are unable to travel
far out into the galactic bulge. The remnants most deeply bound to the black
hole go through a second tidal disruption event upon their first return to
pericenter; if they have not thermally relaxed, they will be completely
disrupted.
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