http://arxiv.org/abs/2211.12140
We present a high angular resolution ($\sim1”$) and wide-field ($2′.9 \times 1′.9$) image of the 1.3-mm continuum, CO($J$ = 2–1) line, and SiO($J$ = 5–4) line emissions toward an embedded protocluster, FIR3, FIR4, and FIR5, in the Orion Molecular Cloud 2 obtained from the Atacama Large Millimeter/submillimeter Array (ALMA). We identify 51 continuum sources, 36 of which are newly identified in this study. Their dust masses, projected sizes, and $\mathrm{H_2}$ gas number densities are estimated to be $3.8 \times 10^{-5}$–$ 1.1 \times 10^{-2} \mathrm{M_{\odot}}$, 290–2000\,au, and $6.4 \times 10^{6}$–$3.3 \times 10^{8}\,\mathrm{cm^{-3}}$, respectively. The results of a Jeans analysis show that $\sim80\,\%$ of the protostellar sources and $\sim15\,\%$ of the prestellar sources are gravitationally bound. We identify 12 molecular outflows traced in the CO($J$ = 2–1) emission, six of which are newly detected. We spatially resolve shocked gas structures traced by the SiO($J$ = 5–4) emission in this region for the first time. We identify shocked gas originating from outflows and other shocked regions. These results provide direct evidence of an interaction between a dust condensation, FIR4, and an energetic outflow driven by HOPS-370 located within FIR3. A comparison of the outflow dynamical timescales, fragmentation timescales, and protostellar ages shows that the previously proposed triggered star-formation scenario in FIR4 is not strongly supported. We also discuss the spatial distribution of filaments identified in our continuum image by comparing it with a previously identified hub-fiber system in the $\mathrm{N_2H^+}$ line.
A. Sato, S. Takahashi, S. Ishii, et. al.
Wed, 23 Nov 22
6/71
Comments: 45 pages, 24 figures