Eruptive Behavior of Magnetically Layered Protoplanetary Disks in Low Metallicity Environments. (arXiv:2101.05764v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Kadam_K/0/1/0/all/0/1">Kundan Kadam</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vorobyov_E/0/1/0/all/0/1">Eduard Vorobyov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kospal_A/0/1/0/all/0/1">Ágnes Kóspál</a>
A protoplanetary disk typically forms a dead zone near its midplane at the
distance of a few au from the central protostar. Accretion through such a
magnetically layered disk can be intrinsically unstable and has been associated
with episodic outbursts in young stellar objects. We present the first
investigation into the effects of low metallicity environment on the structure
of the dead zone as well as the resulting outbursting behavior of the
protoplanetary disk. We conducted global numerical hydrodynamic simulations of
protoplanetary disk formation and evolution in the thin-disk limit. The
consequences of metallicity were considered via its effects on the gas and dust
opacity of the disk, the thickness of the magnetically active surface layer,
and the temperature of the prestellar cloud core. We show that the metal poor
disks accumulate much more mass in the innermost regions, as compared to the
solar metallicity counterparts. The duration of the outbursting phase also
varies with metallicity – the low metallicity disks showed more powerful
luminosity eruptions with a shorter burst phase, which was confined mostly to
the early, embedded stages of the disk evolution. The lowest metallicity disks
with the higher cloud core temperature showed the most significant differences.
The occurrence of outbursts was relatively rare in the disks around low mass
stars and this was especially true at lowest metallicities. We conclude that
the metal content of the disk environment can have profound effects on both the
disk structure and evolution in terms of episodic accretion.
A protoplanetary disk typically forms a dead zone near its midplane at the
distance of a few au from the central protostar. Accretion through such a
magnetically layered disk can be intrinsically unstable and has been associated
with episodic outbursts in young stellar objects. We present the first
investigation into the effects of low metallicity environment on the structure
of the dead zone as well as the resulting outbursting behavior of the
protoplanetary disk. We conducted global numerical hydrodynamic simulations of
protoplanetary disk formation and evolution in the thin-disk limit. The
consequences of metallicity were considered via its effects on the gas and dust
opacity of the disk, the thickness of the magnetically active surface layer,
and the temperature of the prestellar cloud core. We show that the metal poor
disks accumulate much more mass in the innermost regions, as compared to the
solar metallicity counterparts. The duration of the outbursting phase also
varies with metallicity – the low metallicity disks showed more powerful
luminosity eruptions with a shorter burst phase, which was confined mostly to
the early, embedded stages of the disk evolution. The lowest metallicity disks
with the higher cloud core temperature showed the most significant differences.
The occurrence of outbursts was relatively rare in the disks around low mass
stars and this was especially true at lowest metallicities. We conclude that
the metal content of the disk environment can have profound effects on both the
disk structure and evolution in terms of episodic accretion.
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