Origin of the Shell Structure in the Primary Outflow from IRAS 15398-3359

Fuente: arXiv
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Main Authors: Hanawa, Tomoyuki, Okoda, Yuki, Yang, Yao-Lun, Sakai, Nami
Format: Preprint
Published: 2025
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_version_ 1866916758653239296
author Hanawa, Tomoyuki
Okoda, Yuki
Yang, Yao-Lun
Sakai, Nami
author_facet Hanawa, Tomoyuki
Okoda, Yuki
Yang, Yao-Lun
Sakai, Nami
contents IRAS 15398-3359, a Class 0 protostar in Lupus I star forming region, is associated with three generations of outflows. The primary outflow, i.e., the most recent one, shows internal structure named ``shell structure'' in the near infrared emission map. The shell structure is also seen in the emission lines of CO, H$_2$CO, and others species. We find a similar structure in an underexpanded jet produced in aerodynamics and other engineering applications. A high pressure gas ejected through a nozzle expands to form a supersonic flow. When the pressure of the ejected gas becomes lower than that of the ambient gas, the jet is compressed to form a shock wave. The shock heated gas expands again to form substructures along the jet. We examine the similarity between the primary outflow of IRAS 15398-3359 and industrial underexpanded jet and the possibility that the shell structure of the former is due to repeated expansion and compression in the direction perpendicular to the jet propagation.
format Preprint
id arxiv_https___arxiv_org_abs_2505_08470
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Origin of the Shell Structure in the Primary Outflow from IRAS 15398-3359
Hanawa, Tomoyuki
Okoda, Yuki
Yang, Yao-Lun
Sakai, Nami
Astrophysics of Galaxies
Solar and Stellar Astrophysics
IRAS 15398-3359, a Class 0 protostar in Lupus I star forming region, is associated with three generations of outflows. The primary outflow, i.e., the most recent one, shows internal structure named ``shell structure'' in the near infrared emission map. The shell structure is also seen in the emission lines of CO, H$_2$CO, and others species. We find a similar structure in an underexpanded jet produced in aerodynamics and other engineering applications. A high pressure gas ejected through a nozzle expands to form a supersonic flow. When the pressure of the ejected gas becomes lower than that of the ambient gas, the jet is compressed to form a shock wave. The shock heated gas expands again to form substructures along the jet. We examine the similarity between the primary outflow of IRAS 15398-3359 and industrial underexpanded jet and the possibility that the shell structure of the former is due to repeated expansion and compression in the direction perpendicular to the jet propagation.
title Origin of the Shell Structure in the Primary Outflow from IRAS 15398-3359
topic Astrophysics of Galaxies
Solar and Stellar Astrophysics
url https://arxiv.org/abs/2505.08470