B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+
We report the first measurement of polarized thermal dust emission toward the entire infrared dark cloud G11.11−0.12 taken by the polarimeter SOFIA/HAWC+ at 214 μ m. The obtained magnetic fields ( B -fields) from the polarized emission of the early-stage and massive filament tend to be perpendicular...
| Main Authors: | , , , , , , , , , , |
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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/acdb6e |
| _version_ | 1797695405800030208 |
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| author | Nguyen Bich Ngoc Pham Ngoc Diep Thiem Hoang Le Ngoc Tram Nguyen Chau Giang Ngân Lê Thuong D. Hoang Nguyen Thi Phuong Nguyen Minh Khang Dieu D. Nguyen Bao Truong |
| author_facet | Nguyen Bich Ngoc Pham Ngoc Diep Thiem Hoang Le Ngoc Tram Nguyen Chau Giang Ngân Lê Thuong D. Hoang Nguyen Thi Phuong Nguyen Minh Khang Dieu D. Nguyen Bao Truong |
| author_sort | Nguyen Bich Ngoc |
| collection | DOAJ |
| description | We report the first measurement of polarized thermal dust emission toward the entire infrared dark cloud G11.11−0.12 taken by the polarimeter SOFIA/HAWC+ at 214 μ m. The obtained magnetic fields ( B -fields) from the polarized emission of the early-stage and massive filament tend to be perpendicular to its spine. We produce a map of B -field strengths for the center region of the filament. The strengths vary in the range of 100–600 μ G and are strongest along the filament's spine. The central region is sub-Alfvénic and mostly subcritical, meaning that B -fields dominate over turbulence and are strong enough to resist gravitational collapse. The alignment and properties of dust grains in the filament are studied using radiative torque (RAT) theory. We find the decrease of polarization degree P with emission intensity I , i.e., depolarization effect, of the form P ∝ I ^− ^α with α ∼ 0.8–0.9, implying a significant loss of grain alignment in the filament's spine. The depolarization can be explained by the decrease in RAT alignment efficiency toward the denser regions with weaker radiation field, which cannot be explained by B -field tangling. We study the effect of the enhanced magnetic relaxation by embedded iron inclusions on RAT alignment and find that the high polarization fraction P ∼ 20%–30% in the outer layer of the filament is potential evidence for the magnetically enhanced RAT alignment mechanism. This is the first time this effect is evaluated in a filament. Based on the polarization fraction and RAT alignment theory, we also find evidence for grain growth in the filament. |
| first_indexed | 2024-03-12T03:11:57Z |
| format | Article |
| id | doaj.art-23242aa94edf476cb6c593f03b1d60d9 |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T03:11:57Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-23242aa94edf476cb6c593f03b1d60d92023-09-03T14:22:28ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0195316610.3847/1538-4357/acdb6eB-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+Nguyen Bich Ngoc0https://orcid.org/0000-0002-5913-5554Pham Ngoc Diep1https://orcid.org/0000-0002-2808-0888Thiem Hoang2https://orcid.org/0000-0003-2017-0982Le Ngoc Tram3https://orcid.org/0000-0002-6488-8227Nguyen Chau Giang4https://orcid.org/0000-0002-3681-671XNgân Lê5https://orcid.org/0000-0003-1990-1717Thuong D. Hoang6https://orcid.org/0000-0002-3437-5228Nguyen Thi Phuong7https://orcid.org/0000-0002-4372-5509Nguyen Minh Khang8https://orcid.org/0000-0001-9657-8728Dieu D. Nguyen9https://orcid.org/0000-0002-5678-1008Bao Truong10https://orcid.org/0000-0001-9654-8051Department of Astrophysics, Vietnam National Space Center, Vietnam Academy of Science and Technology , 18 Hoang Quoc Viet, Hanoi, Vietnam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology , 18 Hoang Quoc Viet, Hanoi, VietnamDepartment of Astrophysics, Vietnam National Space Center, Vietnam Academy of Science and Technology , 18 Hoang Quoc Viet, Hanoi, Vietnam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology , 18 Hoang Quoc Viet, Hanoi, VietnamKorea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea; University of Science and Technology , Korea, 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of KoreaMax-Planck-Institut für Radioastronomie , Auf dem Hügel 69, D-53-121, Bonn, GermanyKorea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea; University of Science and Technology , Korea, 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of KoreaInstitute of Astronomy, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University , Grudziądzka 5, 87-100 Toruń, PolandCenter for Data-Driven Discovery, Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI), UTIAS, The University of Tokyo , Kashiwa, Chiba 277-8583, JapanDepartment of Astrophysics, Vietnam National Space Center, Vietnam Academy of Science and Technology , 18 Hoang Quoc Viet, Hanoi, Vietnam; Korea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of KoreaInstitute For Interdisciplinary Research in Science and Education (IFIRSE) , ICISE, 07 Science Avenue, Ghenh Rang Ward, 55121 Quy Nhon City, Binh Dinh Province, VietnamUniversité de Lyon1, Ens de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon (CRAL) UMR5574 , F-69230 SaintGenis-Laval, FranceKorea Astronomy and Space Science Institute , 776 Daedeokdae-ro, Yuseong-gu, Daejeon 34055, Republic of Korea; University of Science and Technology , Korea, 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of KoreaWe report the first measurement of polarized thermal dust emission toward the entire infrared dark cloud G11.11−0.12 taken by the polarimeter SOFIA/HAWC+ at 214 μ m. The obtained magnetic fields ( B -fields) from the polarized emission of the early-stage and massive filament tend to be perpendicular to its spine. We produce a map of B -field strengths for the center region of the filament. The strengths vary in the range of 100–600 μ G and are strongest along the filament's spine. The central region is sub-Alfvénic and mostly subcritical, meaning that B -fields dominate over turbulence and are strong enough to resist gravitational collapse. The alignment and properties of dust grains in the filament are studied using radiative torque (RAT) theory. We find the decrease of polarization degree P with emission intensity I , i.e., depolarization effect, of the form P ∝ I ^− ^α with α ∼ 0.8–0.9, implying a significant loss of grain alignment in the filament's spine. The depolarization can be explained by the decrease in RAT alignment efficiency toward the denser regions with weaker radiation field, which cannot be explained by B -field tangling. We study the effect of the enhanced magnetic relaxation by embedded iron inclusions on RAT alignment and find that the high polarization fraction P ∼ 20%–30% in the outer layer of the filament is potential evidence for the magnetically enhanced RAT alignment mechanism. This is the first time this effect is evaluated in a filament. Based on the polarization fraction and RAT alignment theory, we also find evidence for grain growth in the filament.https://doi.org/10.3847/1538-4357/acdb6eInterstellar magnetic fieldsInterstellar filamentsStar forming regionsStar formationFar infrared astronomyInterstellar dust |
| spellingShingle | Nguyen Bich Ngoc Pham Ngoc Diep Thiem Hoang Le Ngoc Tram Nguyen Chau Giang Ngân Lê Thuong D. Hoang Nguyen Thi Phuong Nguyen Minh Khang Dieu D. Nguyen Bao Truong B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+ The Astrophysical Journal Interstellar magnetic fields Interstellar filaments Star forming regions Star formation Far infrared astronomy Interstellar dust |
| title | B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+ |
| title_full | B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+ |
| title_fullStr | B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+ |
| title_full_unstemmed | B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+ |
| title_short | B-fields and Dust in Interstellar Filaments Using Dust Polarization (BALLAD-POL). I. The Massive Filament G11.11–0.12 Observed by SOFIA/HAWC+ |
| title_sort | b fields and dust in interstellar filaments using dust polarization ballad pol i the massive filament g11 11 0 12 observed by sofia hawc |
| topic | Interstellar magnetic fields Interstellar filaments Star forming regions Star formation Far infrared astronomy Interstellar dust |
| url | https://doi.org/10.3847/1538-4357/acdb6e |
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