Starship Asterisk*

Composite image of the cluster forming region, OMC-2/ FIR 3 and FIR 4, obtained with ALMA (red: carbon monoxide gas, orange: emission from the dust, blue: silicon monoxide gas). Credit: ALMA (ESO/NAOJ/NRAO), A. Sato et al.

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Astronomers revealed fast gas outflows from a baby star strongly colliding with nearby dense gas where a group of baby stars are being born. The result suggests that the outflow collision shakes the cradle of the baby stars, and has a significant impact on the ongoing star formation process. This study provides insight into the star formation process within cluster regions where baby stars are born simultaneously in a complex and crowded environment.

Baby stars (protostars) form due to the collapse of dense cores of gas and dust. At the same time, some of the material is ejected by the protostar. This phenomenon is called molecular outflow and shows a bipolar and collimated structure. The extension of the molecular outflow can be more than a million times bigger than the protostar. The molecular outflow is much easier to find than the compact and embedded protostar itself, hence searching for outflows can be a powerful tool to explore the birthplaces of protostars.

The majority of stars form together with other stars in a crowded environment called a cluster formation. Theoretical studies predict that the outflows within the star forming cluster play an important role and can themself trigger (or at least facilitate) further star-formation activity. Alternatively, ongoing star formation could be disrupted by neighboring molecular outflows. Although star formation in a cluster environment is common, observational studies that spatially resolve the individual protostars within the cluster are still limited because the target sources are located relatively far from us. ALMA (Atacama Large Millimeter/submillimeter Array) is a powerful instrument to resolve gas and dust distributions and reveal the complex star formation processes in cluster forming regions. ...

• arXiv > astro-ph > arXiv:2211.12140 > 22 Nov 2022 (v1), 23 Nov 2022 (v2)