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arXiv · 2208.10673

CORINOS I: JWST/MIRI Spectroscopy and Imaging of a Class 0 protostar IRAS 15398-3359

Yao-Lun Yang·Joel D. Green·Klaus M. Pontoppidan·Jennifer B. Bergner·L. Ilsedore Cleeves·Neal J. Evans II·Robin T. Garrod·Mihwa Jin·Chul Hwan Kim·Jaeyeong Kim·Jeong-Eun Lee·Nami Sakai·Christopher N. Shingledecker·Brielle Shope·John J. Tobin·Ewine van Dishoeck
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Abstract

The origin of complex organic molecules (COMs) in young Class 0 protostars has been one of the major questions in astrochemistry and star formation. While COMs are thought to form on icy dust grains via gas-grain chemistry, observational constraints on their formation pathways have been limited to gas-phase detection. Sensitive mid-infrared spectroscopy with JWST enables unprecedented investigation of COM formation by measuring their ice absorption features. We present an overview of JWST/MIRI MRS spectroscopy and imaging of a young Class 0 protostar, IRAS 15398-3359, and identify several major solid-state absorption features in the 4.9-28 $\mu$m wavelength range. These can be attributed to common ice species, such as H$_2$O, CH$_3$OH, NH$_3$, and CH$_4$, and may have contributions from more complex organic species, such as C$_2$H$_5$OH and CH$_3$CHO. The MRS spectra show many weaker emission lines at 6-8 $\mu$m, which are due to warm CO gas and water vapor, possibly from a young embedded disk previously unseen. Finally, we detect emission lines from [Fe II], [Ne II], [S I], and H$_2$, tracing a bipolar jet and outflow cavities. MIRI imaging serendipitously covers the south-western (blue-shifted) outflow lobe of IRAS 15398-3359, showing four shell-like structures similar to the outflows traced by molecular emission at sub-mm wavelengths. This overview analysis highlights the vast potential of JWST/MIRI observations and previews scientific discoveries in the coming years.

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BibTeXRIS

Yao-Lun Yang, Joel D. Green, Klaus M. Pontoppidan, Jennifer B. Bergner, L. Ilsedore Cleeves, Neal J. Evans II, Robin T. Garrod, Mihwa Jin, Chul Hwan Kim, Jaeyeong Kim, Jeong-Eun Lee, Nami Sakai, Christopher N. Shingledecker, Brielle Shope, John J. Tobin, Ewine van Dishoeck. 2022-08-23. CORINOS I: JWST/MIRI Spectroscopy and Imaging of a Class 0 protostar IRAS 15398-3359. https://doi.org/10.3847/2041-8213%2Faca289

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