A centrally concentrated sub-solar mass starless core in the Taurus L1495 filamentary complex. (arXiv:1904.05490v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Tokuda_K/0/1/0/all/0/1">Kazuki Tokuda</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tachihara_K/0/1/0/all/0/1">Kengo Tachihara</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Saigo_K/0/1/0/all/0/1">Kazuya Saigo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andre_P/0/1/0/all/0/1">Phillipe André</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miyamoto_Y/0/1/0/all/0/1">Yosuke Miyamoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zahorecz_S/0/1/0/all/0/1">Sarolta Zahorecz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Inutsuka_S/0/1/0/all/0/1">Shu-ichiro Inutsuka</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Matsumoto_T/0/1/0/all/0/1">Tomoaki Matsumoto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Takashima_T/0/1/0/all/0/1">Tatsuyuki Takashima</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Machida_M/0/1/0/all/0/1">Masahiro N. Machida</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:+Taniguchi_K/0/1/0/all/0/1">Kotomi Taniguchi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fukui_Y/0/1/0/all/0/1">Yasuo Fukui</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kawamura_A/0/1/0/all/0/1">Akiko Kawamura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tatematsu_K/0/1/0/all/0/1">Ken'ichi Tatematsu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kandori_R/0/1/0/all/0/1">Ryo Kandori</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Onishi_T/0/1/0/all/0/1">Toshikazu Onishi</a>
The formation scenario of brown dwarfs is still unclear because observational
studies to investigate its initial condition are quite limited. Our systematic
survey of nearby low-mass star-forming regions using the Atacama Compact Array
(aka Morita array) and the IRAM 30 m telescope in 1.2 mm continuum has
identified a centrally concentrated starless condensation with the central
H$_2$ volume density of $sim$10$^6$ cm$^{-3}$, MC5-N, connected to a narrow
(width $sim$0.03 pc) filamentary cloud in the Taurus L1495 region. The mass of
the core is $sim$0.2-0.4 $M_{odot}$, which is an order of magnitude smaller
than typical low-mass prestellar cores. Taking into account a typical core to
star formation efficiency for prestellar cores ($sim$20-40%) in nearby
molecular clouds, brown dwarf(s) or very low-mass star(s) may be going to be
formed in this core. We have found possible substructures at the high-density
portion of the core, although much higher angular resolution observation is
needed to clearly confirm them. The subsequent N$_2$H$^+$ and N$_2$D$^+$
observations using the Nobeyama 45 m telescope have confirmed the
high-deuterium fractionation ($sim$30%). These dynamically and chemically
evolved features indicate that this core is on the verge of proto-brown dwarf
or very low-mass star formation and an ideal source to investigate the initial
conditions of such low-mass objects via gravitational collapse and/or
fragmentation of the filamentary cloud complex.
The formation scenario of brown dwarfs is still unclear because observational
studies to investigate its initial condition are quite limited. Our systematic
survey of nearby low-mass star-forming regions using the Atacama Compact Array
(aka Morita array) and the IRAM 30 m telescope in 1.2 mm continuum has
identified a centrally concentrated starless condensation with the central
H$_2$ volume density of $sim$10$^6$ cm$^{-3}$, MC5-N, connected to a narrow
(width $sim$0.03 pc) filamentary cloud in the Taurus L1495 region. The mass of
the core is $sim$0.2-0.4 $M_{odot}$, which is an order of magnitude smaller
than typical low-mass prestellar cores. Taking into account a typical core to
star formation efficiency for prestellar cores ($sim$20-40%) in nearby
molecular clouds, brown dwarf(s) or very low-mass star(s) may be going to be
formed in this core. We have found possible substructures at the high-density
portion of the core, although much higher angular resolution observation is
needed to clearly confirm them. The subsequent N$_2$H$^+$ and N$_2$D$^+$
observations using the Nobeyama 45 m telescope have confirmed the
high-deuterium fractionation ($sim$30%). These dynamically and chemically
evolved features indicate that this core is on the verge of proto-brown dwarf
or very low-mass star formation and an ideal source to investigate the initial
conditions of such low-mass objects via gravitational collapse and/or
fragmentation of the filamentary cloud complex.
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