ALMA discovery of a dual dense probably rotating outflow from a massive young stellar object G18.88MME. (arXiv:2106.09626v1 [astro-ph.GA])

ALMA discovery of a dual dense probably rotating outflow from a massive young stellar object G18.88MME. (arXiv:2106.09626v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Zinchenko_I/0/1/0/all/0/1">I. I. Zinchenko</a> (1), <a href="http://arxiv.org/find/astro-ph/1/au:+Dewangan_L/0/1/0/all/0/1">L. K. Dewangan</a> (2), <a href="http://arxiv.org/find/astro-ph/1/au:+Baug_T/0/1/0/all/0/1">T. Baug</a> (3), <a href="http://arxiv.org/find/astro-ph/1/au:+Ojha_D/0/1/0/all/0/1">D. K. Ojha</a> (4), <a href="http://arxiv.org/find/astro-ph/1/au:+Bhadari_N/0/1/0/all/0/1">N. K. Bhadari</a> (2,5) ((1) Institute of Applied Physics of the Russian Academy of Sciences, (2) Physical Research Laboratory, Ahmedabad, India, (3) Satyendra Nath Bose National Centre for Basic Sciences, Kolkata, India, (4) Tata Institute of Fundamental Research, Mumbai, India, (5) Indian Institute of Technology Gandhinagar Palaj, Gandhinagar, India)

We report the discovery of a very dense jet-like fast molecular outflow
surrounded by a wide-angle wind in a massive young stellar object (MYSO)
G18.88MME (stellar mass $sim$8 M$_{odot}$) powering an Extended Green Object
G18.89$-$0.47. Four cores MM1-4 are identified in the Atacama Large
Millimeter/submillimeter Array (ALMA) 1.3 mm continuum map (resolution
$sim$0.$”$8) toward G18.88MME, and are seen at the center of the emission
structure (extent $sim$0.3 pc $times$ 0.2 pc) detected in the ALMA map.
G18.88MME is embedded in the core MM1 (mass $sim$13-18 M$_{odot}$), where no
radio continuum emission is detected. The molecular outflow centered at MM1 is
investigated in the SiO(5-4), HC$_{3}$N(24-23) and $^{13}$CO(2-1) lines. The
detection of HC$_{3}$N in the outflow is rare in MYSOs and indicates its very
high density. The position-velocity diagrams display a fast narrow outflow
(extent $sim$28000 AU) and a slower wide-angle more extended outflow toward
MM1, and both of these components show a transverse velocity gradient
indicative of a possible rotation. All these observed features together make
G18.88MME as a unique object for studying the unification of the jet-driven and
wind-driven scenarios of molecular outflows in MYSOs.

We report the discovery of a very dense jet-like fast molecular outflow
surrounded by a wide-angle wind in a massive young stellar object (MYSO)
G18.88MME (stellar mass $sim$8 M$_{odot}$) powering an Extended Green Object
G18.89$-$0.47. Four cores MM1-4 are identified in the Atacama Large
Millimeter/submillimeter Array (ALMA) 1.3 mm continuum map (resolution
$sim$0.$”$8) toward G18.88MME, and are seen at the center of the emission
structure (extent $sim$0.3 pc $times$ 0.2 pc) detected in the ALMA map.
G18.88MME is embedded in the core MM1 (mass $sim$13-18 M$_{odot}$), where no
radio continuum emission is detected. The molecular outflow centered at MM1 is
investigated in the SiO(5-4), HC$_{3}$N(24-23) and $^{13}$CO(2-1) lines. The
detection of HC$_{3}$N in the outflow is rare in MYSOs and indicates its very
high density. The position-velocity diagrams display a fast narrow outflow
(extent $sim$28000 AU) and a slower wide-angle more extended outflow toward
MM1, and both of these components show a transverse velocity gradient
indicative of a possible rotation. All these observed features together make
G18.88MME as a unique object for studying the unification of the jet-driven and
wind-driven scenarios of molecular outflows in MYSOs.

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