Synthetic Observations of the Infalling Rotating Envelope: Links between the Physical Structure and Observational Features
We performed synthetic observations of the Ulrich, Cassen, and Moosman (UCM) model to understand the relation between the physical structures of the infalling envelope around a protostar and their observational features in molecular lines, adopting L1527 as an example. We also compared the physical...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad0634 |
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| author | Shoji Mori Yuri Aikawa Yoko Oya Satoshi Yamamoto Nami Sakai |
| author_facet | Shoji Mori Yuri Aikawa Yoko Oya Satoshi Yamamoto Nami Sakai |
| author_sort | Shoji Mori |
| collection | DOAJ |
| description | We performed synthetic observations of the Ulrich, Cassen, and Moosman (UCM) model to understand the relation between the physical structures of the infalling envelope around a protostar and their observational features in molecular lines, adopting L1527 as an example. We also compared the physical structure and synthetic position–velocity ( P–V ) diagrams of the UCM model and a simple ballistic (SB) model. There are multiple ways to compare synthetic data with observational data. We first calculated the correlation coefficient. The UCM model and the SB model show similarly good correlation with the observational data. While the correlation reflects the overall similarity between the cube datasets, we can alternatively compare specific local features, such as the centrifugal barrier in the SB model or the centrifugal radius in the UCM model. We evaluated systematic uncertainties in these methods. In the case of L1527, the stellar mass values estimated using these methods are all lower than the value derived from previous Keplerian analysis of the disk. This may indicate that the gas infall motion in the envelope is retarded by, e.g., magnetic fields. We also showed analytically that, in the UCM model, the spin-up feature of the P–V diagram is due to the infall velocity rather than the rotation. The line-of-sight velocity V is thus ∝ x ^−0.5 , where x is the offset. If the infall is retarded, rotational velocity should dominate so that V is proportional to x ^−1 , as is often observed in the protostellar envelope. |
| first_indexed | 2024-03-08T14:45:43Z |
| format | Article |
| id | doaj.art-202fa490e1d34e418ac1cb9fc75efd55 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T14:45:43Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-202fa490e1d34e418ac1cb9fc75efd552024-01-11T09:50:36ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-0196113110.3847/1538-4357/ad0634Synthetic Observations of the Infalling Rotating Envelope: Links between the Physical Structure and Observational FeaturesShoji Mori0https://orcid.org/0000-0002-7002-939XYuri Aikawa1https://orcid.org/0000-0003-3283-6884Yoko Oya2https://orcid.org/0000-0002-0197-8751Satoshi Yamamoto3https://orcid.org/0000-0002-9865-0970Nami Sakai4https://orcid.org/0000-0002-3297-4497Astronomical Institute, Graduate School of Science, Tohoku University , 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan ; mori.s@astr.tohoku.ac.jp; Department of Astronomy, Graduate School of Science, The University of Tokyo , 113-0033, Tokyo, JapanDepartment of Astronomy, Graduate School of Science, The University of Tokyo , 113-0033, Tokyo, JapanCenter for Gravitational Physics and Quantum Information, Yukawa Institute for Theoretical Physics, Kyoto University , Kyoto, 606-8502, JapanThe Graduate University for Advanced Studies SOKENDAI , Shonan Village, Hayama, Kanagawa 240-0193, Japan; Research Center for the Early Universe, The University of Tokyo , 7-3-1, Hongo, Bunkyoku, Tokyo 113-0033, JapanRIKEN Cluster for Pioneering Research , 2-1, Hirosawa, Wako-shi, Saitama 351-0198, JapanWe performed synthetic observations of the Ulrich, Cassen, and Moosman (UCM) model to understand the relation between the physical structures of the infalling envelope around a protostar and their observational features in molecular lines, adopting L1527 as an example. We also compared the physical structure and synthetic position–velocity ( P–V ) diagrams of the UCM model and a simple ballistic (SB) model. There are multiple ways to compare synthetic data with observational data. We first calculated the correlation coefficient. The UCM model and the SB model show similarly good correlation with the observational data. While the correlation reflects the overall similarity between the cube datasets, we can alternatively compare specific local features, such as the centrifugal barrier in the SB model or the centrifugal radius in the UCM model. We evaluated systematic uncertainties in these methods. In the case of L1527, the stellar mass values estimated using these methods are all lower than the value derived from previous Keplerian analysis of the disk. This may indicate that the gas infall motion in the envelope is retarded by, e.g., magnetic fields. We also showed analytically that, in the UCM model, the spin-up feature of the P–V diagram is due to the infall velocity rather than the rotation. The line-of-sight velocity V is thus ∝ x ^−0.5 , where x is the offset. If the infall is retarded, rotational velocity should dominate so that V is proportional to x ^−1 , as is often observed in the protostellar envelope.https://doi.org/10.3847/1538-4357/ad0634Star formationProtostarsAstrochemistry |
| spellingShingle | Shoji Mori Yuri Aikawa Yoko Oya Satoshi Yamamoto Nami Sakai Synthetic Observations of the Infalling Rotating Envelope: Links between the Physical Structure and Observational Features The Astrophysical Journal Star formation Protostars Astrochemistry |
| title | Synthetic Observations of the Infalling Rotating Envelope: Links between the Physical Structure and Observational Features |
| title_full | Synthetic Observations of the Infalling Rotating Envelope: Links between the Physical Structure and Observational Features |
| title_fullStr | Synthetic Observations of the Infalling Rotating Envelope: Links between the Physical Structure and Observational Features |
| title_full_unstemmed | Synthetic Observations of the Infalling Rotating Envelope: Links between the Physical Structure and Observational Features |
| title_short | Synthetic Observations of the Infalling Rotating Envelope: Links between the Physical Structure and Observational Features |
| title_sort | synthetic observations of the infalling rotating envelope links between the physical structure and observational features |
| topic | Star formation Protostars Astrochemistry |
| url | https://doi.org/10.3847/1538-4357/ad0634 |
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