Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Long-lived Remnants from Binary Neutron Star Mergers   Massive neutron star (NS) with lifetimes of at least several seconds are
expected to be the result of a sizable fraction of NS mergers. We study their
formation using a large set of numerical relativity simulations. We show that
they are initially endowed with angular momentum that significantly exceeds the
mass-shedding limit for rigidly-rotating equilibria. We find that
gravitational-wave (GW) emission is not able to remove this excess angular
momentum within the time over which solid body rotation should be achieved.
Instead, we argue that the excess angular momentum could be carried away by
massive winds. Long-lived merger remnants are also formed with larger
gravitational masses than those of rigidly-rotating NSs having the same number
of baryons. The excess mass is likely radiated in the form of neutrinos. The
evolution of long-lived remnants on the viscous timescale is thus determined by
the interplay of finite-temperature effects, mass ejection, and neutrinos with
potentially dramatic consequences for the remnants' properties and stability.
We also provide an empirical fit for the spin of the remnant at the end of its
viscous evolution as a function of its final mass, and we discuss the
implications for the magnetar model of short gamma-ray bursts (SGRBs). Finally,
we investigate the possible electromagnetic signatures associated with the
viscous ejecta. Massive outflows possibly resulting from the formation of
long-lived remnants would power unusually bright, blue kilonova counterparts to
GW events and SGRBs whose detection would provide smoking gun evidence for the
formation of long-lived remnants.

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The categories of this paper are: patt-sol
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The categories of this paper are: q-alg
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The categories of this paper are: eess
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The categories of this paper are: adap-org
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The categories of this paper are: econ
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The categories of this paper are: nlin
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The categories of this paper are: bayes-an
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The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: hep-th
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The categories of this paper are: cond-mat
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The categories of this paper are: math
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The categories of this paper are: chem-ph
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: q-fin