Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211
To study the transportation of magnetic flux from large to small scales in protostellar sources, we analyzed the Nobeyama 45 m N _2 H ^+ (1–0), JCMT 850 μ m polarization, and Atacama Large Millimeter/submillimeter Array (ALMA) C ^18 O (2–1) and 1.3 and 0.8 mm (polarized) continuum data of the Class...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/aca47f |
| _version_ | 1797697245803446272 |
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| author | Hsi-Wei Yen Patrick M. Koch Chin-Fei Lee Naomi Hirano Nagayoshi Ohashi Jinshi Sai (Insa Choi) Shigehisa Takakuwa Ya-Wen Tang Ken’ichi Tatematsu Bo Zhao |
| author_facet | Hsi-Wei Yen Patrick M. Koch Chin-Fei Lee Naomi Hirano Nagayoshi Ohashi Jinshi Sai (Insa Choi) Shigehisa Takakuwa Ya-Wen Tang Ken’ichi Tatematsu Bo Zhao |
| author_sort | Hsi-Wei Yen |
| collection | DOAJ |
| description | To study the transportation of magnetic flux from large to small scales in protostellar sources, we analyzed the Nobeyama 45 m N _2 H ^+ (1–0), JCMT 850 μ m polarization, and Atacama Large Millimeter/submillimeter Array (ALMA) C ^18 O (2–1) and 1.3 and 0.8 mm (polarized) continuum data of the Class 0 protostar HH 211. The magnetic field strength in the dense core on a 0.1 pc scale was estimated with the single-dish line and polarization data using the Davis–Chandrasekhar–Fermi method, and that in the protostellar envelope on a 600 au scale was estimated from the force balance between the gravity and magnetic field tension by analyzing the gas kinematics and magnetic field structures with the ALMA data. Our analysis suggests that from 0.1 pc–600 au scales, the magnetic field strength increases from 40–107 μ G to 0.3–1.2 mG with a scaling relation between the magnetic field strength and density of B ∝ ρ ^0.36±0.08 , and the mass-to-flux ratio increases from 1.2–3.7 to 9.1–32.3. The increase in the mass-to-flux ratio could suggest that the magnetic field is partially decoupled from the neutral matter between 0.1 pc and 600 au scales, and hint at efficient ambipolar diffusion in the infalling protostellar envelope in HH 211, which is the dominant nonideal magnetohydrodynamic effect considering the density on these scales. Thus, our results could support the scenario of efficient ambipolar diffusion enabling the formation of the 20 au Keplerian disk in HH 211. |
| first_indexed | 2024-03-12T03:37:35Z |
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| id | doaj.art-42e9fb9f49a54c14a1f0dbf2be688937 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:37:35Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-42e9fb9f49a54c14a1f0dbf2be6889372023-09-03T13:07:56ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0194213210.3847/1538-4357/aca47fIncreasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211Hsi-Wei Yen0https://orcid.org/0000-0003-1412-893XPatrick M. Koch1https://orcid.org/0000-0003-2777-5861Chin-Fei Lee2https://orcid.org/0000-0002-3024-5864Naomi Hirano3https://orcid.org/0000-0001-9304-7884Nagayoshi Ohashi4https://orcid.org/0000-0003-0998-5064Jinshi Sai (Insa Choi)5https://orcid.org/0000-0003-4361-5577Shigehisa Takakuwa6https://orcid.org/0000-0003-0845-128XYa-Wen Tang7https://orcid.org/0000-0002-0675-276XKen’ichi Tatematsu8https://orcid.org/0000-0002-8149-8546Bo Zhao9Academia Sinica Institute of Astronomy and Astrophysics , 11F of Astro-Math Bldg, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan ; hwyen@asiaa.sinica.edu.twAcademia Sinica Institute of Astronomy and Astrophysics , 11F of Astro-Math Bldg, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan ; hwyen@asiaa.sinica.edu.twAcademia Sinica Institute of Astronomy and Astrophysics , 11F of Astro-Math Bldg, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan ; hwyen@asiaa.sinica.edu.twAcademia Sinica Institute of Astronomy and Astrophysics , 11F of Astro-Math Bldg, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan ; hwyen@asiaa.sinica.edu.twAcademia Sinica Institute of Astronomy and Astrophysics , 11F of Astro-Math Bldg, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan ; hwyen@asiaa.sinica.edu.twAcademia Sinica Institute of Astronomy and Astrophysics , 11F of Astro-Math Bldg, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan ; hwyen@asiaa.sinica.edu.twAcademia Sinica Institute of Astronomy and Astrophysics , 11F of Astro-Math Bldg, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan ; hwyen@asiaa.sinica.edu.tw; Department of Physics and Astronomy, Graduate School of Science and Engineering, Kagoshima University , 1-21-35 Korimoto, Kagoshima, Kagoshima 890-0065, JapanAcademia Sinica Institute of Astronomy and Astrophysics , 11F of Astro-Math Bldg, 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan ; hwyen@asiaa.sinica.edu.twNobeyama Radio Observatory, National Astronomical Observatory of Japan, National Institutes of Natural Sciences , Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305, Japan; Department of Astronomical Science, The Graduate University for Advanced Studies , SOKENDAI, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, JapanDepartment of Physics & Astronomy, McMaster University , Hamilton, ON L8S 4K1, CanadaTo study the transportation of magnetic flux from large to small scales in protostellar sources, we analyzed the Nobeyama 45 m N _2 H ^+ (1–0), JCMT 850 μ m polarization, and Atacama Large Millimeter/submillimeter Array (ALMA) C ^18 O (2–1) and 1.3 and 0.8 mm (polarized) continuum data of the Class 0 protostar HH 211. The magnetic field strength in the dense core on a 0.1 pc scale was estimated with the single-dish line and polarization data using the Davis–Chandrasekhar–Fermi method, and that in the protostellar envelope on a 600 au scale was estimated from the force balance between the gravity and magnetic field tension by analyzing the gas kinematics and magnetic field structures with the ALMA data. Our analysis suggests that from 0.1 pc–600 au scales, the magnetic field strength increases from 40–107 μ G to 0.3–1.2 mG with a scaling relation between the magnetic field strength and density of B ∝ ρ ^0.36±0.08 , and the mass-to-flux ratio increases from 1.2–3.7 to 9.1–32.3. The increase in the mass-to-flux ratio could suggest that the magnetic field is partially decoupled from the neutral matter between 0.1 pc and 600 au scales, and hint at efficient ambipolar diffusion in the infalling protostellar envelope in HH 211, which is the dominant nonideal magnetohydrodynamic effect considering the density on these scales. Thus, our results could support the scenario of efficient ambipolar diffusion enabling the formation of the 20 au Keplerian disk in HH 211.https://doi.org/10.3847/1538-4357/aca47fStar formationInterstellar magnetic fieldsStar forming regionsProtostarsCircumstellar disks |
| spellingShingle | Hsi-Wei Yen Patrick M. Koch Chin-Fei Lee Naomi Hirano Nagayoshi Ohashi Jinshi Sai (Insa Choi) Shigehisa Takakuwa Ya-Wen Tang Ken’ichi Tatematsu Bo Zhao Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211 The Astrophysical Journal Star formation Interstellar magnetic fields Star forming regions Protostars Circumstellar disks |
| title | Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211 |
| title_full | Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211 |
| title_fullStr | Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211 |
| title_full_unstemmed | Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211 |
| title_short | Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211 |
| title_sort | increasing mass to flux ratio from the dense core to the protostellar envelope around the class 0 protostar hh 211 |
| topic | Star formation Interstellar magnetic fields Star forming regions Protostars Circumstellar disks |
| url | https://doi.org/10.3847/1538-4357/aca47f |
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