Salt, Hot Water, and Silicon Compounds Tracing Massive Twin Disks. (arXiv:2007.02962v4 [astro-ph.SR] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Tanaka_K/0/1/0/all/0/1">Kei E. I. Tanaka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_Y/0/1/0/all/0/1">Yichen Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hirota_T/0/1/0/all/0/1">Tomoya Hirota</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sakai_N/0/1/0/all/0/1">Nami Sakai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Motogi_K/0/1/0/all/0/1">Kazuhito Motogi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tomida_K/0/1/0/all/0/1">Kengo Tomida</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tan_J/0/1/0/all/0/1">Jonathan C. Tan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rosero_V/0/1/0/all/0/1">Viviana Rosero</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Higuchi_A/0/1/0/all/0/1">Aya E. Higuchi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ohashi_S/0/1/0/all/0/1">Satoshi Ohashi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_M/0/1/0/all/0/1">Mengyao Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sugiyama_K/0/1/0/all/0/1">Koichiro Sugiyama</a>
We report results of 0.05″-resolution observations toward the O-type
proto-binary system IRAS 16547-4247 with the Atacama Large
Millimeter/submillimeter Array (ALMA). We present dynamical and chemical
structures of the circumbinary disk, circumstellar disks, outflows and jets,
illustrated by multi-wavelength continuum and various molecular lines. In
particular, we detect sodium chloride, silicon compounds, and
vibrationally-excited water lines as probes of the individual protostellar
disks at a scale of 100 au. These are complementary to typical hot-core
molecules tracing the circumbinary structures on a 1000-au scale. The H2O line
tracing inner-disks has an upper-state energy of Eu/k>3000K, indicating a high
temperature of the disks. On the other hand, despite the detected transitions
of NaCl, SiO, and SiS not necessarily having high upper-state energies, they
are enhanced only in the vicinity of the protostars. We interpret that these
molecules are the products of dust destruction, which only happens in the inner
disks. This is the second detection of alkali metal halide in protostellar
systems after the case of the disk of Orion Source I, and also one of few
massive protostellar disks associated with high-energy transition water and
silicon compounds. These new results suggest these “hot-disk” lines may be
common in innermost disks around massive protostars, and have great potential
for future research of massive star formation. We also tentatively find that
the twin disks are counter-rotating, which might give a hint of the origin of
the massive proto-binary system IRAS 16547-4247.
We report results of 0.05″-resolution observations toward the O-type
proto-binary system IRAS 16547-4247 with the Atacama Large
Millimeter/submillimeter Array (ALMA). We present dynamical and chemical
structures of the circumbinary disk, circumstellar disks, outflows and jets,
illustrated by multi-wavelength continuum and various molecular lines. In
particular, we detect sodium chloride, silicon compounds, and
vibrationally-excited water lines as probes of the individual protostellar
disks at a scale of 100 au. These are complementary to typical hot-core
molecules tracing the circumbinary structures on a 1000-au scale. The H2O line
tracing inner-disks has an upper-state energy of Eu/k>3000K, indicating a high
temperature of the disks. On the other hand, despite the detected transitions
of NaCl, SiO, and SiS not necessarily having high upper-state energies, they
are enhanced only in the vicinity of the protostars. We interpret that these
molecules are the products of dust destruction, which only happens in the inner
disks. This is the second detection of alkali metal halide in protostellar
systems after the case of the disk of Orion Source I, and also one of few
massive protostellar disks associated with high-energy transition water and
silicon compounds. These new results suggest these “hot-disk” lines may be
common in innermost disks around massive protostars, and have great potential
for future research of massive star formation. We also tentatively find that
the twin disks are counter-rotating, which might give a hint of the origin of
the massive proto-binary system IRAS 16547-4247.
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