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22 results on '"Sven van Loo"'

1. Size-selective accretion of dust onto CPDs: Low CPD masses and filtration of larger grains

Author

Samuel M Karlin, Olja Panić, and Sven van Loo

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

The major satellites of Jupiter and Saturn are believed to have formed in circumplanetary discs, which orbit forming giant protoplanets. Gas and dust in CPDs have different distributions and affect each other by drag, which varies with grain size. Yet simulations of multiple dust grain sizes with separate dynamics have not been done before. We seek to assess how much dust of each grain size there is in circumplanetary discs. We run multifluid 3D hydrodynamical simulations including gas and four discrete grain sizes of dust from 1$\mu$m to 1mm, representing a continuous distribution. We consider a 1 $M_\mathrm{Jup}$ protoplanet embedded in a protoplanetary disc around a 1 $M_{\odot}$ star. Our results show a truncated MRN distribution at smaller grain sizes, which starts to tail off by $a=100\mu$m and is near zero at 1mm. Large dust grains, which hold most of the dust mass, have very inefficient accretion to the CPD, due to dust filtration. Therefore CPDs' dust masses must be small, with mass ratio ~ a few $\times 10^{-6}$ to the protoplanet. These masses and the corresponding millimetre opacities are in line with CPD fluxes observed to date., Comment: 14 pages, 15 figures; accepted for publication in MNRAS

Published
2023
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2. An exploration of dust grain growth within WCd systems using an advected scalar dust model

Author

Sven Van Loo, Julian Pittard, and Joseph Eatson

Subjects
Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

Dust production is one of the more curious phenomena observed in massive binary systems with interacting winds. The high temperatures, UV photon flux and violent shocks should destroy any dust grains that condense. However, in some extreme cases dust production yields of approximately 30% of the total mass loss rate of the stellar winds have been observed. In order to better understand this phenomenon a parameter space exploration was performed using a series of numerical models of dust producing carbon phase Wolf-Rayet (WCd) systems. These models incorporated a passive scalar dust model simulating dust growth, destruction and radiative cooling. We find that reasonable dust yields were produced by these simulations. Significant changes in the dust yield were caused by changing the mass loss rates of the stars, with a greater mass loss rate contributing to increased dust yields. Similarly, a close orbit between the stars also resulted in higher dust yields. Finally, a high velocity wind shear, which induces Kelvin-Helmholtz (KH) instabilities and wind mixing, drastically increases the dust yields., 13 pages, 18 figures, 10 tables

Published
2022

3. B-fields in Star-forming Region Observations (BISTRO): Magnetic Fields in the Filamentary Structures of Serpens Main

Author

Woojin Kwon, Kate Pattle, Sarah Sadavoy, Charles L. H. Hull, Doug Johnstone, Derek Ward-Thompson, James Di Francesco, Patrick M. Koch, Ray Furuya, Yasuo Doi, Valentin J. M. Le Gouellec, Jihye Hwang, A-Ran Lyo, Archana Soam, Xindi Tang, Thiem Hoang, Florian Kirchschlager, Chakali Eswaraiah, Lapo Fanciullo, Kyoung Hee Kim, Takashi Onaka, Vera Könyves, Ji-hyun Kang, Chang Won Lee, Motohide Tamura, Pierre Bastien, Tetsuo Hasegawa, Shih-Ping Lai, Keping Qiu, David Berry, Doris Arzoumanian, Tyler L. Bourke, Do-Young Byun, Wen Ping Chen, Huei-Ru Vivien Chen, Mike Chen, Zhiwei Chen, Tao-Chung Ching, Jungyeon Cho, Yunhee Choi, Minho Choi, Antonio Chrysostomou, Eun Jung Chung, Simon Coudé, Sophia Dai, Pham Ngoc Diep, Yan Duan, Hao-Yuan Duan, David Eden, Jason Fiege, Laura M. Fissel, Erica Franzmann, Per Friberg, Rachel Friesen, Gary Fuller, Tim Gledhill, Sarah Graves, Jane Greaves, Matt Griffin, Qilao Gu, Ilseung Han, Jennifer Hatchell, Saeko Hayashi, Martin Houde, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Miju Kang, Janik Karoly, Akimasa Kataoka, Koji Kawabata, Francisca Kemper, Kee-Tae Kim, Gwanjeong Kim, Mi-Ryang Kim, Shinyoung Kim, Jongsoo Kim, Jason Kirk, Masato I. N. Kobayashi, Takayoshi Kusune, Jungmi Kwon, Kevin Lacaille, Chi-Yan Law, Chin-Fei Lee, Yong-Hee Lee, Hyeseung Lee, Jeong-Eun Lee, Sang-Sung Lee, Dalei Li, Di Li, Hua-bai Li, Sheng-Jun Lin, Sheng-Yuan Liu, Hong-Li Liu, Junhao Liu, Tie Liu, Xing Lu, Steve Mairs, Masafumi Matsumura, Brenda Matthews, Gerald Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nguyen Bich Ngoc, Nagayoshi Ohashi, Geumsook Park, Harriet Parsons, Nicolas Peretto, Felix Priestley, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Jonathan Rawlings, Mark G. Rawlings, Brendan Retter, John Richer, Andrew Rigby, Hiro Saito, Giorgio Savini, Masumichi Seta, Yoshito Shimajiri, Hiroko Shinnaga, Mehrnoosh Tahani, Ya-Wen Tang, Kohji Tomisaka, Le Ngoc Tram, Yusuke Tsukamoto, Serena Viti, Hongchi Wang, Jia-Wei Wang, Anthony Whitworth, Jintai Wu, Jinjin Xie, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Hyeong-Sik Yun, Tetsuya Zenko, Yapeng Zhang, Chuan-Peng Zhang, Guoyin Zhang, Jianjun Zhou, Lei Zhu, Ilse de Looze, Philippe André, C. Darren Dowell, Stewart Eyres, Sam Falle, Jean-François Robitaille, Sven van Loo, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France

Subjects
POLARIZATION, FOS: Physical sciences, F500, IMAGING POLARIMETRY, 1ST, INTERSTELLAR CLOUDS, Astrophysics::Solar and Stellar Astrophysics, SCUBA-2, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], LEGACY, Astronomy and Astrophysics, VELOCITY, Astrophysics - Astrophysics of Galaxies, SPITZER, Astrophysics - Solar and Stellar Astrophysics, Physics and Astronomy, Space and Planetary Science, [SDU]Sciences of the Universe [physics], OUTFLOWS, Astrophysics of Galaxies (astro-ph.GA), STRENGTHS
Abstract

We present 850 $��$m polarimetric observations toward the Serpens Main molecular cloud obtained using the POL-2 polarimeter on the James Clerk Maxwell Telescope (JCMT) as part of the B-fields In STar-forming Region Observations (BISTRO) survey. These observations probe the magnetic field morphology of the Serpens Main molecular cloud on about 6000 au scales, which consists of cores and six filaments with different physical properties such as density and star formation activity. Using the histogram of relative orientation (HRO) technique, we find that magnetic fields are parallel to filaments in less dense filamentary structures where $N_{H_2} < 0.93\times 10^{22}$ cm$^{-2}$ (magnetic fields perpendicular to density gradients), while being perpendicular to filaments (magnetic fields parallel to density gradients) in dense filamentary structures with star formation activity. Moreover, applying the HRO technique to denser core regions, we find that magnetic field orientations change to become perpendicular to density gradients again at $N_{H_2} \approx 4.6 \times 10^{22}$ cm$^{-2}$. This can be interpreted as a signature of core formation. At $N_{H_2} \approx 16 \times 10^{22}$ cm$^{-2}$ magnetic fields change back to being parallel to density gradients once again, which can be understood to be due to magnetic fields being dragged in by infalling material. In addition, we estimate the magnetic field strengths of the filaments ($B_{POS} = 60-300~��$G)) using the Davis-Chandrasekhar-Fermi method and discuss whether the filaments are gravitationally unstable based on magnetic field and turbulence energy densities., 18 pages, accepted for publication in ApJ

Published
2022

4. The JCMT BISTRO-2 survey : magnetic fields of the massive DR21 filament

Author

Tao-Chung Ching, Keping Qiu, Di Li, Zhiyuan Ren, Shih-Ping Lai, David Berry, Kate Pattle, Ray Furuya, Derek Ward-Thompson, Doug Johnstone, Patrick M. Koch, Chang Won Lee, Thiem Hoang, Tetsuo Hasegawa, Woojin Kwon, Pierre Bastien, Chakali Eswaraiah, Jia-Wei Wang, Kyoung Hee Kim, Jihye Hwang, Archana Soam, A-Ran Lyo, Junhao Liu, Valentin J. M. Le Gouellec, Doris Arzoumanian, Anthony Whitworth, James Di Francesco, Frédérick Poidevin, Tie Liu, Simon Coudé, Mehrnoosh Tahani, Hong-Li Liu, Takashi Onaka, Dalei Li, Motohide Tamura, Zhiwei Chen, Xindi Tang, Florian Kirchschlager, Tyler L. Bourke, Do-Young Byun, Mike Chen, Huei-Ru Vivien Chen, Wen Ping Chen, Jungyeon Cho, Yunhee Choi, Youngwoo Choi, Minho Choi, Antonio Chrysostomou, Eun Jung Chung, Y. Sophia Dai, Pham Ngoc Diep, Yasuo Doi, Yan Duan, Hao-Yuan Duan, David Eden, Lapo Fanciullo, Jason Fiege, Laura M. Fissel, Erica Franzmann, Per Friberg, Rachel Friesen, Gary Fuller, Tim Gledhill, Sarah Graves, Jane Greaves, Matt Griffin, Qilao Gu, Ilseung Han, Saeko Hayashi, Martin Houde, Charles L. H. Hull, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Vera Könyves, Ji-hyun Kang, Miju Kang, Janik Karoly, Akimasa Kataoka, Koji Kawabata, Francisca Kemper, Jongsoo Kim, Mi-Ryang Kim, Shinyoung Kim, Hyosung Kim, Kee-Tae Kim, Gwanjeong Kim, Jason Kirk, Masato I. N. Kobayashi, Takayoshi Kusune, Jungmi Kwon, Kevin Lacaille, Chi-Yan Law, Sang-Sung Lee, Hyeseung Lee, Jeong-Eun Lee, Chin-Fei Lee, Yong-Hee Lee, Guangxing Li, Hua-bai Li, Sheng-Jun Lin, Sheng-Yuan Liu, Xing Lu, Steve Mairs, Masafumi Matsumura, Brenda Matthews, Gerald Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nguyen Bich Ngoc, Nagayoshi Ohashi, Geumsook Park, Harriet Parsons, Nicolas Peretto, Felix Priestley, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Mark Rawlings, Jonathan Rawlings, Brendan Retter, John Richer, Andrew Rigby, Sarah Sadavoy, Hiro Saito, Giorgio Savini, Masumichi Seta, Yoshito Shimajiri, Hiroko Shinnaga, Ya-Wen Tang, Kohji Tomisaka, Le Ngoc Tram, Yusuke Tsukamoto, Serena Viti, Hongchi Wang, Jintai Wu, Jinjin Xie, Meng-Zhe Yang, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Hyeong-Sik Yun, Tetsuya Zenko, Chuan-Peng Zhang, Yapeng Zhang, Guoyin Zhang, Jianjun Zhou, Lei Zhu, Ilse de Looze, Philippe André, C. Darren Dowell, Stewart Eyres, Sam Falle, Jean-François Robitaille, Sven van Loo, National Natural Science Foundation of China, Chinese Academy of Sciences, Natural Sciences and Engineering Research Council of Canada, Ministerio de Ciencia, Innovación y Universidades (España), National Research Foundation of Korea, National Research, Japan Society for the Promotion of Science, Agencia Estatal de Investigación (España), Ching, Tao-Chung [0000-0001-8516-2532], Qiu, Keping [0000-0002-5093-5088], Li, Di [0000-0003-3010-7661], Ren, Zhiyuan [0000-0003-4659-1742], Lai, Shih-Ping [0000-0001-5522-486X], Berry, David [0000-0001-6524-2447], Pattle, Kate [0000-0002-8557-3582], Furuya, Ray [0000-0003-0646-8782], Ward-Thompson, Derek [0000-0003-1140-2761], Johnstone, Doug [0000-0002-6773-459X], Koch, Patrick M [0000-0003-2777-5861], Lee, Chang Won [0000-0002-3179-6334], Hoang, Thiem [0000-0003-2017-0982], Hasegawa, Tetsuo [0000-0003-1853-0184], Kwon, Woojin [0000-0003-4022-4132], Bastien, Pierre [0000-0002-0794-3859], Eswaraiah, Chakali [0000-0003-4761-6139], Wang, Jia-Wei [0000-0002-6668-974X], Kim, Kyoung Hee [0000-0001-9597-7196], Hwang, Jihye [0000-0001-7866-2686], Soam, Archana [0000-0002-6386-2906], Lyo, A-Ran [0000-0002-9907-8427], Liu, Junhao [0000-0002-4774-2998], Le Gouellec, Valentin JM [0000-0002-5714-799X], Arzoumanian, Doris [0000-0002-1959-7201], Whitworth, Anthony [0000-0002-1178-5486], Francesco, James Di [0000-0002-9289-2450], Poidevin, Frédérick [0000-0002-5391-5568], Liu, Tie [0000-0002-5286-2564], Coudé, Simon [0000-0002-0859-0805], Tahani, Mehrnoosh [0000-0001-8749-1436], Liu, Hong-Li [0000-0003-3343-9645], Onaka, Takashi [0000-0002-8234-6747], Tamura, Motohide [0000-0002-6510-0681], Chen, Zhiwei [0000-0003-0849-0692], Tang, Xindi [0000-0002-4154-4309], Kirchschlager, Florian [0000-0002-3036-0184], Bourke, Tyler L [0000-0001-7491-0048], Byun, Do-Young [0000-0003-1157-4109], Chen, Huei-Ru Vivien [0000-0002-9774-1846], Chen, Wen Ping [0000-0003-0262-272X], Cho, Jungyeon [0000-0003-1725-4376], Chrysostomou, Antonio [0000-0002-9583-8644], Chung, Eun Jung [0000-0003-0014-1527], Dai, Y Sophia [0000-0002-7928-416X], Diep, Pham Ngoc [0000-0002-2808-0888], Doi, Yasuo [0000-0001-8746-6548], Duan, Hao-Yuan [0000-0002-7022-4742], Eden, David [0000-0002-5881-3229], Fanciullo, Lapo [0000-0001-9930-9240], Fissel, Laura M [0000-0002-4666-609X], Franzmann, Erica [0000-0003-2142-0357], Friberg, Per [0000-0002-8010-8454], Friesen, Rachel [0000-0001-7594-8128], Fuller, Gary [0000-0001-8509-1818], Gledhill, Tim [0000-0002-2859-4600], Graves, Sarah [0000-0001-9361-5781], Greaves, Jane [0000-0002-3133-413X], Gu, Qilao [0000-0002-2826-1902], Hayashi, Saeko [0000-0001-5026-490X], Houde, Martin [0000-0003-4420-8674], Hull, Charles LH [0000-0002-8975-7573], Inoue, Tsuyoshi [0000-0002-7935-8771], Inutsuka, Shu-ichiro [0000-0003-4366-6518], Jeong, Il-Gyo [0000-0002-5492-6832], Könyves, Vera [0000-0002-3746-1498], Kang, Ji-hyun [0000-0001-7379-6263], Kang, Miju [0000-0002-5016-050X], Karoly, Janik [0000-0001-5996-3600], Kataoka, Akimasa [0000-0003-4562-4119], Kawabata, Koji [0000-0001-6099-9539], Kemper, Francisca [0000-0003-2743-8240], Kim, Jongsoo [0000-0002-1229-0426], Kim, Shinyoung [0000-0001-9333-5608], Kim, Kee-Tae [0000-0003-2412-7092], Kim, Gwanjeong [0000-0003-2011-8172], Kirk, Jason [0000-0002-4552-7477], Kobayashi, Masato IN [0000-0003-3990-1204], Kusune, Takayoshi [0000-0002-9218-9319], Kwon, Jungmi [0000-0003-2815-7774], Lacaille, Kevin [0000-0001-9870-5663], Law, Chi-Yan [0000-0003-1964-970X], Lee, Sang-Sung [0000-0002-6269-594X], Lee, Hyeseung [0000-0003-3465-3213], Lee, Jeong-Eun [0000-0003-3119-2087], Lee, Chin-Fei [0000-0002-3024-5864], Lee, Yong-Hee [0000-0001-6047-701X], Li, Guangxing [0000-0003-3144-1952], Li, Hua-bai [0000-0003-2641-9240], Lin, Sheng-Jun [0000-0002-6868-4483], Liu, Sheng-Yuan [0000-0003-4603-7119], Lu, Xing [0000-0003-2619-9305], Mairs, Steve [0000-0002-6956-0730], Matsumura, Masafumi [0000-0002-6906-0103], Matthews, Brenda [0000-0003-3017-9577], Moriarty-Schieven, Gerald [0000-0002-0393-7822], Nagata, Tetsuya [0000-0001-9264-9015], Nakamura, Fumitaka [0000-0001-5431-2294], Ngoc, Nguyen Bich [0000-0002-5913-5554], Ohashi, Nagayoshi [0000-0003-0998-5064], Park, Geumsook [0000-0001-8467-3736], Parsons, Harriet [0000-0002-6327-3423], Pyo, Tae-Soo [0000-0002-3273-0804], Qian, Lei [0000-0003-0597-0957], Rao, Ramprasad [0000-0002-1407-7944], Rawlings, Mark [0000-0002-6529-202X], Rawlings, Jonathan [0000-0001-5560-1303], Richer, John [0000-0002-9693-6860], Rigby, Andrew [0000-0002-3351-2200], Savini, Giorgio [0000-0003-4449-9416], Shimajiri, Yoshito [0000-0001-9368-3143], Shinnaga, Hiroko [0000-0001-9407-6775], Tang, Ya-Wen [0000-0002-0675-276X], Tomisaka, Kohji [0000-0003-2726-0892], Tram, Le Ngoc [0000-0002-6488-8227], Viti, Serena [0000-0001-8504-8844], Wang, Hongchi [0000-0003-0746-7968], Wu, Jintai [0000-0001-7276-3590], Xie, Jinjin [0000-0002-2738-146X], Yen, Hsi-Wei [0000-0003-1412-893X], Yoo, Hyunju [0000-0002-8578-1728], Yun, Hyeong-Sik [0000-0001-6842-1555], Zhang, Chuan-Peng [0000-0002-4428-3183], Zhang, Yapeng [0000-0002-5102-2096], Zhou, Jianjun [0000-0003-0356-818X], André, Philippe [0000-0002-3413-2293], Falle, Sam [0000-0002-9829-0426], Robitaille, Jean-François [0000-0001-5079-8573], van Loo, Sven [0000-0003-4746-8500], and Apollo - University of Cambridge Repository

Subjects
STAR-FORMING REGIONS, SUBMILLIMETER POLARIZATION, HERSCHEL, FOS: Physical sciences, Astronomy and Astrophysics, MU-M POLARIZATION, MOLECULAR CLOUD, Astrophysics - Astrophysics of Galaxies, 1ST, Astrophysics - Solar and Stellar Astrophysics, Physics and Astronomy, 5101 Astronomical Sciences, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), SCUBA-2, GOULD BELT SURVEY, DUST EMISSION, 51 Physical Sciences, Solar and Stellar Astrophysics (astro-ph.SR), FAR-INFRARED POLARIMETRY
Abstract

Tao-Chung Ching et al., We present 850 μm dust polarization observations of the massive DR21 filament from the B-fields In STar-forming Region Observations (BISTRO) survey, using the POL-2 polarimeter and the SCUBA-2 camera on the James Clerk Maxwell Telescope. We detect ordered magnetic fields perpendicular to the parsec-scale ridge of the DR21 main filament. In the subfilaments, the magnetic fields are mainly parallel to the filamentary structures and smoothly connect to the magnetic fields of the main filament. We compare the POL-2 and Planck dust polarization observations to study the magnetic field structures of the DR21 filament on 0.1–10 pc scales. The magnetic fields revealed in the Planck data are well-aligned with those of the POL-2 data, indicating a smooth variation of magnetic fields from large to small scales. The plane-of-sky magnetic field strengths derived from angular dispersion functions of dust polarization are 0.6–1.0 mG in the DR21 filament and ∼0.1 mG in the surrounding ambient gas. The mass-to-flux ratios are found to be magnetically supercritical in the filament and slightly subcritical to nearly critical in the ambient gas. The alignment between column density structures and magnetic fields changes from random alignment in the low-density ambient gas probed by Planck to mostly perpendicular in the high-density main filament probed by James Clerk Maxwell Telescope. The magnetic field structures of the DR21 filament are in agreement with MHD simulations of a strongly magnetized medium, suggesting that magnetic fields play an important role in shaping the DR21 main filament and subfilaments., This work is supported by National Natural Science Foundation of China (NSFC) grant Nos. 11988101, U1931117, 11725313, and 12073061 and the CAS International Partnership Program of Chinese Academy of Sciences grant No. 114A11KYSB20160008. T.-C.C. is funded by Chinese Academy of Sciences Taiwan Young Talent Program grant No. 2018TW2JB0002. T.-C.C. and C.E. were supported by Special Funding for Advanced Users, budgeted and administrated by Center for Astronomical Mega-Science (CAMS), Chinese Academy of Sciences. K.P. is a Royal Society University Research Fellow, supported by grant No. URF\R1\211322. D.J. is supported by the National Research Council of Canada and by a Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant. P.M.K. is supported by the Ministry of Science and Technology (MoST) in Taiwan through grants 109-2112-M-001-022 and 110-2112-M-001-057. C.W.L. is supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2019R1A2C1010851), and by the Korea Astronomy and Space Science Institute grant funded by the Korea government (MSIT; Project No. 2022-1-840-05). T.H. is supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) through the Mid-career Research Program (2019R1A2C1087045). W.K. was supported by the NRF grant funded by the MSIT (2021R1F1A1061794). C.E. acknowledges the financial support from grant RJF/2020/000071 as a part of Ramanujan Fellowship awarded by the Science and Engineering Research Board (SERB), Department of Science and Technology (DST), Govt. of India. F.P. acknowledges support from the Spanish State Research Agency (AEI) under grant No. PID2019-105552RB-C43. M.T. is supported by JSPS KAKENHI grant Nos. 18H05442, 15H02063, and 22000005. J.K. is supported by JSPS KAKENHI grant No. 19K14775. L.F. and F.K. acknowledge the support by the MoST in Taiwan through grant 107-2119-M-001-031-MY3 and Academia Sinica through grant AS-IA-106-M03. L.F. acknowledges the support by the MoST in Taiwan through grants 111-2811-M-005-007 and 109-2112-M-005-003-MY3. C.L.H.H. acknowledges the support of the NAOJ Fellowship and JSPS KAKENHI grants 18K13586 and 20K14527. F.K. is supported by the Spanish program Unidad de Excelencia María de Maeztu CEX2020-001058-M, financed by MCIN/AEI/10.13039/501100011033. K.Q. is partially supported by National Key R&D Program of China No. 2022YFA1603100, and acknowledges the National Natural Science Foundation of China (NSFC) grant U1731237. S.P.L. acknowledges grants from the Ministry of Science and Technology of Taiwan 106-2119-M-007-021-MY3 and 109-2112-M-007-010-MY3. Y.D. acknowledges the support of JSPS KAKENHI grants 25247016 and 18H01250. Y.S.D. is supported by the National Key R&D Program of China for grant No. 2022YFA1605300, and NSFC grants Nos. 12273051, 11933003.

Published
2022

5. The JCMT BISTRO survey: A spiral magnetic field in a hub-filament structure, monoceros R2

Author

Jihye Hwang, Jongsoo Kim, Kate Pattle, Chang Won Lee, Patrick M. Koch, Doug Johnstone, Kohji Tomisaka, Anthony Whitworth, Ray S. Furuya, Ji-hyun Kang, A-Ran Lyo, Eun Jung Chung, Doris Arzoumanian, Geumsook Park, Woojin Kwon, Shinyoung Kim, Motohide Tamura, Jungmi Kwon, Archana Soam, Ilseung Han, Thiem Hoang, Kyoung Hee Kim, Takashi Onaka, Chakali Eswaraiah, Derek Ward-Thompson, Hong-Li Liu, Xindi Tang, Wen Ping Chen, Masafumi Matsumura, Thuong Duc Hoang, Zhiwei Chen, Valentin J. M. Le Gouellec, Florian Kirchschlager, Frédérick Poidevin, Pierre Bastien, Keping Qiu, Tetsuo Hasegawa, Shih-Ping Lai, Do-Young Byun, Jungyeon Cho, Minho Choi, Youngwoo Choi, Yunhee Choi, Il-Gyo Jeong, Miju Kang, Hyosung Kim, Kee-Tae Kim, Jeong-Eun Lee, Sang-Sung Lee, Yong-Hee Lee, Hyeseung Lee, Mi-Ryang Kim, Hyunju Yoo, Hyeong-Sik Yun, Mike Chen, James Di Francesco, Jason Fiege, Laura M. Fissel, Erica Franzmann, Martin Houde, Kevin Lacaille, Brenda Matthews, Sarah Sadavoy, Gerald Moriarty-Schieven, Mehrnoosh Tahani, Tao-Chung Ching, Y. Sophia Dai, Yan Duan, Qilao Gu, Chi-Yan Law, Dalei Li, Di Li, Guangxing Li, Hua-bai Li, Tie Liu, Xing Lu, Lei Qian, Hongchi Wang, Jintai Wu, Jinjin Xie, Jinghua Yuan, Chuan-Peng Zhang, Guoyin Zhang, Yapeng Zhang, Jianjun Zhou, Lei Zhu, David Berry, Per Friberg, Sarah Graves, Junhao Liu, Steve Mairs, Harriet Parsons, Mark Rawlings, Yasuo Doi, Saeko Hayashi, Charles L. H. Hull, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Akimasa Kataoka, Koji Kawabata, Gwanjeong Kim, Masato I. N. Kobayashi, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Tae-Soo Pyo, Hiro Saito, Masumichi Seta, Yoshito Shimajiri, Hiroko Shinnaga, Yusuke Tsukamoto, Tetsuya Zenko, Huei-Ru Vivien Chen, Hao-Yuan Duan, Lapo Fanciullo, Francisca Kemper, Chin-Fei Lee, Sheng-Jun Lin, Sheng-Yuan Liu, Nagayoshi Ohashi, Ramprasad Rao, Ya-Wen Tang, Jia-Wei Wang, Meng-Zhe Yang, Hsi-Wei Yen, Tyler L. Bourke, Antonio Chrysostomou, Victor Debattista, David Eden, Stewart Eyres, Sam Falle, Gary Fuller, Tim Gledhill, Jane Greaves, Matt Griffin, Jennifer Hatchell, Janik Karoly, Jason Kirk, Vera Könyves, Steven Longmore, Sven van Loo, Ilse de Looze, Nicolas Peretto, Felix Priestley, Jonathan Rawlings, Brendan Retter, John Richer, Andrew Rigby, Giorgio Savini, Anna Scaife, Serena Viti, Pham Ngoc Diep, Nguyen Bich Ngoc, Le Ngoc Tram, Philippe André, Simon Coudé, C. Darren Dowell, Rachel Friesen, Jean-Franćois Robitaille, National Research Foundation of Korea, Japan Society for the Promotion of Science, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), and National Science Foundation (US)

Subjects
POLARIZATION, CLOUDS, FOS: Physical sciences, Astronomy and Astrophysics, REGIONS, Astrophysics - Astrophysics of Galaxies, 1ST, DENSE CORES, MODEL, Physics and Astronomy, GRAVITY, POL-2, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), SCUBA-2
Abstract

Hwang et al., We present and analyze observations of polarized dust emission at 850 μm toward the central 1 × 1 pc hub-filament structure of Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the B-fields in Star-forming Region Observations survey. The orientations of the magnetic field follow the spiral structure of Mon R2, which are well described by an axisymmetric magnetic field model. We estimate the turbulent component of the magnetic field using the angle difference between our observations and the best-fit model of the underlying large-scale mean magnetic field. This estimate is used to calculate the magnetic field strength using the Davis–Chandrasekhar–Fermi method, for which we also obtain the distribution of volume density and velocity dispersion using a column density map derived from Herschel data and the C18O (J = 3 − 2) data taken with HARP on the JCMT, respectively. We make maps of magnetic field strengths and mass-to-flux ratios, finding that magnetic field strengths vary from 0.02 to 3.64 mG with a mean value of 1.0 ± 0.06 mG, and the mean critical mass-to-flux ratio is 0.47 ± 0.02. Additionally, the mean Alfvén Mach number is 0.35 ± 0.01. This suggests that, in Mon R2, the magnetic fields provide resistance against large-scale gravitational collapse, and the magnetic pressure exceeds the turbulent pressure. We also investigate the properties of each filament in Mon R2. Most of the filaments are aligned along the magnetic field direction and are magnetically subcritical., J.H. is supported by the University of Science and Technology (UST) Overseas Training Program 2022, funded by the University of Science and Technology, Korea (No. 2022-017). K.P. is a Royal Society University Research Fellow, supported by grant number URF\R1\211322. C.W.L. was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF- 2019R1A2C1010851), and by the Korea Astronomy and Space Science Institute grant funded by the Korea government (MSIT; Project No. 2022-1-840-05). D.J. and J.d.F. are supported by the National Research Council of Canada and by Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grants. G.P. is supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (NRF; 2020R1A6A3A01100208) W.K. was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT; NRF-2021R1F1A1061794). M.T. is supported by JSPS KAKENHI grant Nos. 18H05442, 15H02063, and 22000005. J.K. is supported by JSPS KAKENHI grant No. 19K14775. M.M. is supported by JSPS KAKENHI grant No. 20K03276. F.P. acknowledges support from the Spanish State Research Agency Agencia Estatal de Investigación (AEI) under grant number PID2019-105552RB-C43. S.P.L., H.Y.D., S.J.L., and M.Z.Y. acknowledge grants from the Ministry of Science and Technology of Taiwan 106-2119-M-007-021-MY3 and 109-2112-M-007-010-MY3. C.E. acknowledges the financial support from grant RJF/2020/000071 as a part of a Ramanujan Fellowship awarded by Science and Engineering Research Board (SERB), Department of Science and Technology (DST), Govt. of India. L.F. and F.K. acknowledge support from the Ministry of Science and Technology of Taiwan, under grant No. MoST107-2119-M-001-031- MY3 and from Academia Sinica under grant No. AS-IA-106-M03. L.F. acknowledges the support by the MoST in Taiwan through grants 111-2811-M-005-007 and 109-2112-M-005-003-MY3. F.K. acknowledges support from the Spanish program Unidad de Excelencia María de Maeztu CEX2020-001058-M, financed by MCIN/AEI/10.13039/501100011033. Y.S.D. would like to acknowledge the support from NSFC grants 12273051 and 10878003. M.R. is supported by the international Gemini Observatory, a program of NSFs NOIRLab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation, on behalf of the Gemini partnership of Argentina, Brazil, Canada, Chile, the Republic of Korea, and the United States of America. The JCMT is operated by the East Asian Observatory on behalf of The National Astronomical Observatory of Japan; Academia Sinica Institute of Astronomy and Astrophysics; the Korea Astronomy and Space Science Institute; the Operation, Maintenance and Upgrading Fund for Astronomical Telescopes and Facility Instruments, budgeted from the Ministry of Finance of China. Additional funding support is provided by the Science and Technology Facilities Council of the United Kingdom and participating universities and organizations in the United Kingdom, Canada, and Ireland. Additional funds for the construction of SCUBA-2 were provided by the Canada Foundation for Innovation.

Published
2022

6. Exploring dust growth in the episodic WCd system WR140

Author

Sven Van Loo, Julian Pittard, and Joseph Eatson

Subjects
Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

The wind collision region (WCR) in a colliding wind binary (CWB) is a particularly violent place, as such, it is surprising that it is also a region where significant quantities of interstellar dust can form. In extreme cases, approximately 30% of the total mass loss rate of a system can be converted into dust. These regions are poorly understood, as observation and simulation of these systems are difficult. In our previous paper we simulated dust growth in CWB systems using an advected scalar model and found our model to be suitable for qualitative study. For this paper we simulated the periodic dust forming CWB (WCd) system WR140 with our dust model, to determine how dust growth changes over the systems periastron passage. We found that dust production increases significantly at periastron passage, which is consistent with IR emission of the surrounding dusty shell. We also find that the dust production rate of the system decreases rapidly as the stars recede from each other, though the rate of decrease is significantly lower than the rate of increase during periastron passage. This was found to be due to strong cooling and its associated thermal instabilities, resulting in cool, high-density pockets of gas in the WCR where dust forms. The WCR also shows a degree of hysteresis, resulting in a radiative post-shock flow even when the stars are separated enough for the region to behave adiabatically., Comment: 9 pages, 9 figures, 5 tables

Published
2022
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7. The JCMT BISTRO Survey: An 850/450$\mu$m Polarization Study of NGC 2071IR in OrionB

Author

A-Ran Lyo, Jongsoo Kim, Sarah Sadavoy, Doug Johnstone, David Berry, Kate Pattle, Woojin Kwon, Pierre Bastien, Takashi Onaka, James Di Francesco, Ji-Hyun Kang, Ray Furuya, Charles L. H. Hull, Motohide Tamura, Patrick M. Koch, Derek Ward-Thompson, Tetsuo Hasegawa, Thiem Hoang, Doris Arzoumanian, Chang Won Lee, Chin-Fei Lee, Do-Young Byun, Florian Kirchschlager, Yasuo Doi, Kee-Tae Kim, Jihye Hwang, Pham Ngoc Diep, Lapo Fanciullo, Sang-Sung Lee, Geumsook Park, Hyunju Yoo, Eun Jung Chung, Anthony Whitworth, Steve Mairs, Archana Soam, Tie Liu, Xindi Tang, Simon Coudé, Philippe André, Tyler L. Bourke, Huei-Ru Vivien Chen, Zhiwei Chen, Wen Ping Chen, Mike Chen, Tao-Chung Ching, Jungyeon Cho, Minho Choi, Yunhee Choi, Antonio Chrysostomou, Sophia Dai, C. Darren Dowell, Hao-Yuan Duan, Yan Duan, David Eden, Chakali Eswaraiah, Stewart Eyres, Jason Fiege, Laura M. Fissel, Erica Franzmann, Per Friberg, Rachel Friesen, Gary Fuller, Tim Gledhill, Sarah Graves, Jane Greaves, Matt Griffin, Qilao Gu, Ilseung Han, Jannifer Hatchell, Saeko Hayashi, Martin Houde, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Miju Kang, Akimasa Kataoka, Koji Kawabata, Francisca Kemper, Gwanjeong Kim, Mi-Ryang Kim, Shinyoung Kim, Kyoung Hee Kim, Jason Kirk, Masato I. N. Kobayashi, Vera Könyves, Takayoshi Kusune, Jungmi Kwon, Kevin Lacaille, Shih-Ping Lai, Chi-Yan Law, Jeong-Eun Lee, Yong-Hee Lee, Hyeseung Lee, Dalei Li, Di Li, Hua-Bai Li, Hong-Li Liu, Junhao Liu, Sheng-Yuan Liu, Xing Lu, Masafumi Matsumura, Brenda Matthews, Gerald Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nguyen Bich Ngoc, Nagayoshi Ohashi, Harriet Parsons, Nicolas Peretto, Felix Priestley, Tae-soo Pyo, Lei Qian, Keping Qiu, Ramprasad Rao, Jonathan Rawlings, Mark G. Rawlings, Brendan Retter, John Richer, Andrew Rigby, Hiro Saito, Giorgio Savini, Anna Scaife, Masumichi Seta, Yoshito Shimajiri, Hiroko Shinnaga, Mehrnoosh Tahani, Ya-Wen Tang, Kohji Tomisaka, Le Ngoc Tram, Yusuke Tsukamoto, Serena Viti, Jia-Wei Wang, Hongchi Wang, Jinjin Xie, Hsi-Wei Yen, Jinghua Yuan, Hyeong-Sik Yun, Tetsuya Zenko, Guoyin Zhang, Chuan-Peng Zhang, Yapeng Zhang, Jianjun Zhou, Lei Zhu, Ilse de Looze, Sam Falle, Jean-François Robitaille, Sven van Loo, Lyo, A-Ran [0000-0002-9907-8427], Kim, Jongsoo [0000-0002-1229-0426], Johnstone, Doug [0000-0002-6773-459X], Pattle, Kate [0000-0002-8557-3582], Kwon, Woojin [0000-0003-4022-4132], Bastien, Pierre [0000-0002-0794-3859], Onaka, Takashi [0000-0002-8234-6747], Kang, Ji-Hyun [0000-0001-7379-6263], Furuya, Ray [0000-0003-0646-8782], Hull, Charles L. H. [0000-0002-8975-7573], Tamura, Motohide [0000-0002-6510-0681], Koch, Patrick M. [0000-0003-2777-5861], Ward-Thompson, Derek [0000-0003-1140-2761], Hoang, Thiem [0000-0003-2017-0982], Arzoumanian, Doris [0000-0002-1959-7201], Lee, Chin-Fei [0000-0002-3024-5864], Byun, Do-Young [0000-0003-1157-4109], Kirchschlager, Florian [0000-0002-3036-0184], Doi, Yasuo [0000-0001-8746-6548], Kim, Kee-Tae [0000-0003-2412-7092], Hwang, Jihye [0000-0001-7866-2686], Lee, Sang-Sung [0000-0002-6269-594X], Park, Geumsook [0000-0001-8467-3736], Yoo, Hyunju [0000-0002-8578-1728], Chung, Eun Jung [0000-0003-0014-1527], Mairs, Steve [0000-0002-6956-0730], Soam, Archana [0000-0002-6386-2906], Liu, Tie [0000-0002-5286-2564], Tang, Xindi [0000-0002-4154-4309], Coudé, Simon [0000-0002-0859-0805], André, Philippe [0000-0002-3413-2293], Bourke, Tyler L. [0000-0001-7491-0048], Chen, Zhiwei [0000-0003-0849-0692], Ping Chen, Wen [0000-0002-5519-0628], Ching, Tao-Chung [0000-0001-8516-2532], Cho, Jungyeon [0000-0003-1725-4376], Chrysostomou, Antonio [0000-0002-9583-8644], Eden, David [0000-0002-5881-3229], Franzmann, Erica [0000-0003-2142-0357], Friberg, Per [0000-0002-8010-8454], Friesen, Rachel [0000-0001-7594-8128], Fuller, Gary [0000-0001-8509-1818], Gledhill, Tim [0000-0002-2859-4600], Graves, Sarah [0000-0001-9361-5781], Gu, Qilao [0000-0002-2826-1902], Hatchell, Jannifer [0000-0002-4870-2760], Houde, Martin [0000-0003-4420-8674], Inoue, Tsuyoshi [0000-0002-7935-8771], Inutsuka, Shu-ichiro [0000-0003-4366-6518], Iwasaki, Kazunari [0000-0002-2707-7548], Kang, Miju [0000-0002-5016-050X], Kataoka, Akimasa [0000-0003-4562-4119], Kawabata, Koji [0000-0001-6099-9539], Kemper, Francisca [0000-0003-2743-8240], Kim, Gwanjeong [0000-0003-2011-8172], Kim, Mi-Ryang [0000-0002-1408-7747], Kim, Shinyoung [0000-0001-9333-5608], Kirk, Jason [0000-0002-4552-7477], Kobayashi, Masato I. N. [0000-0003-3990-1204], Könyves, Vera [0000-0002-3746-1498], Kusune, Takayoshi [0000-0002-9218-9319], Kwon, Jungmi [0000-0003-2815-7774], Lacaille, Kevin [0000-0001-9870-5663], Lai, Shih-Ping [0000-0001-5522-486X], Law, Chi-Yan [0000-0003-1964-970X], Lee, Jeong-Eun [0000-0003-3119-2087], Lee, Yong-Hee [0000-0001-6047-701X], Lee, Hyeseung [0000-0003-3465-3213], Li, Di [0000-0003-3010-7661], Li, Hua-Bai [0000-0003-2641-9240], Liu, Junhao [0000-0002-4774-2998], Liu, Sheng-Yuan [0000-0003-4603-7119], Lu, Xing [0000-0003-2619-9305], Matsumura, Masafumi [0000-0002-6906-0103], Matthews, Brenda [0000-0003-3017-9577], Moriarty-Schieven, Gerald [0000-0002-0393-7822], Nagata, Tetsuya [0000-0001-9264-9015], Nakamura, Fumitaka [0000-0001-5431-2294], Ohashi, Nagayoshi [0000-0003-0998-5064], Parsons, Harriet [0000-0002-6327-3423], Pyo, Tae-soo [0000-0002-3273-0804], Qian, Lei [0000-0003-0597-0957], Qiu, Keping [0000-0002-5093-5088], Rao, Ramprasad [0000-0002-1407-7944], Rawlings, Jonathan [0000-0001-5560-1303], Rawlings, Mark G. [0000-0002-6529-202X], Richer, John [0000-0002-9693-6860], Rigby, Andrew [0000-0002-3351-2200], Savini, Giorgio [0000-0003-4449-9416], Shimajiri, Yoshito [0000-0001-9368-3143], Shinnaga, Hiroko [0000-0001-9407-6775], Tang, Ya-Wen [0000-0002-0675-276X], Tomisaka, Kohji [0000-0003-2726-0892], Tram, Le Ngoc [0000-0002-6488-8227], Viti, Serena [0000-0001-8504-8844], Wang, Jia-Wei [0000-0002-6668-974X], Wang, Hongchi [0000-0003-0746-7968], Yen, Hsi-Wei [0000-0003-1412-893X], Yun, Hyeong-Sik [0000-0001-6842-1555], Zhang, Chuan-Peng [0000-0002-4428-3183], and Apollo - University of Cambridge Repository

Subjects
Young stellar object, FAR-INFRARED POLARIZATION, Astrophysics, F500, IMAGING POLARIMETRY, MAGNETIC-FIELDS, Gravitational energy, STAR-FORMATION, interstellar magnetic fields, Bipolar outflow, SCUBA-2, FORMING MOLECULAR CLOUDS, GOULD BELT SURVEY, James Clerk Maxwell Telescope, polarimetry, Physics, interstellar medium, SUBMILLIMETER POLARIZATION, Magnetic energy, Center (category theory), Interstellar Matter and the Local Universe, CORES, Astronomy and Astrophysics, Polarization (waves), Astrophysics - Astrophysics of Galaxies, Magnetic field, Physics and Astronomy, BIPOLAR OUTFLOW, Space and Planetary Science, star forming regions
Abstract

We present the results of simultaneous 450 $\mu$m and 850 $\mu$m polarization observations toward the massive star forming region NGC 2071IR, a target of the BISTRO (B-fields in Star-Forming Region Observations) Survey, using the POL-2 polarimeter and SCUBA-2 camera mounted on the James Clerk Maxwell Telescope. We find a pinched magnetic field morphology in the central dense core region, which could be due to a rotating toroidal disk-like structure and a bipolar outflow originating from the central young stellar object, IRS 3. Using the modified Davis-Chandrasekhar-Fermi method, we obtain a plane-of-sky magnetic field strength of 563$\pm$421 $\mu$G in the central $\sim$0.12 pc region from 850 $\mu$m polarization data. The corresponding magnetic energy density of 2.04$\times$10$^{-8}$ erg cm$^{-3}$ is comparable to the turbulent and gravitational energy densities in the region. We find that the magnetic field direction is very well aligned with the whole of the IRS 3 bipolar outflow structure. We find that the median value of polarization fractions, 3.0 \%, at 450 $\mu$m in the central 3 arcminute region, which is larger than the median value of 1.2 \% at 850 $\mu$m. The trend could be due to the better alignment of warmer dust in the strong radiation environment. We also find that polarization fractions decrease with intensity at both wavelengths, with slopes, determined by fitting a Rician noise model, of $0.59 \pm 0.03$ at 450 $\mu$m and $0.36 \pm 0.04$ at 850 $\mu$m, respectively. We think that the shallow slope at 850 $\mu$m is due to grain alignment at the center being assisted by strong radiation from the central young stellar objects., Comment: 17 pages, 11 figures, 4 tables

Published
2021

8. The JCMT BISTRO Survey: Revealing the Diverse Magnetic Field Morphologies in Taurus Dense Cores with Sensitive Submillimeter Polarimetry

Author

A-Ran Lyo, Nguyen Bich Ngoc, Jean-François Robitaille, L. M. Fissel, Jonathan Rawlings, Yapeng Zhang, Andrew Rigby, Matthew Joseph Griffin, Tetsuo Hasegawa, Ji-hyun Kang, Sam Falle, Jongsoo Kim, Jason Fiege, Il-Gyo Jeong, Ya-Wen Tang, Kate Pattle, Zhiwei Chen, Rachel Friesen, Florian Kirchschlager, Doris Arzoumanian, Chang Won Lee, Jennifer Hatchell, Ramprasad Rao, Shih-Ping Lai, Sung-ju Kang, Di Li, Kevin Lacaille, Keping Qiu, Eun Jung Chung, Dalei Li, Gerald H. Moriarty-Schieven, Archana Soam, Anthony Peter Whitworth, Shu-ichiro Inutsuka, Hua-bai Li, Per Friberg, Doug Johnstone, Lei Qian, Thiem Hoang, Kazunari Iwasaki, Lapo Fanciullo, Pham Ngoc Diep, Sarah Graves, Masato I. N. Kobayashi, Nicolas Peretto, Harriet Parsons, Jungyeon Cho, Hiroyuki Nakanishi, Chuan-Peng Zhang, Y. Shimajiri, Martin Houde, Fumitaka Nakamura, John Richer, Kee-Tae Kim, Serena Viti, Derek Ward-Thompson, Jianjun Zhou, Jason M. Kirk, Geumsook Park, Nagayoshi Ohashi, Erica Franzmann, C. Darren Dowell, Woojin Kwon, Mi-Ryang Kim, Sven Van Loo, Tyler Bourke, Mark G. Rawlings, Ilseung Han, Masumichi Seta, Junhao Liu, Motohide Tamura, Minho Choi, Jinghua Yuan, Hao-Yuan Duan, Hong-Li Liu, Wen Ping Chen, Jinjin Xie, Tie Liu, David Eden, S. P. S. Eyres, Yan Duan, Miju Kang, Charles L. H. Hull, Le Ngoc Tram, Koji S. Kawabata, Giorgio Savini, Sophia Dai, Masafumi Matsumura, Chakali Eswaraiah, Tae-Soo Pyo, Francisca Kemper, Yong-Hee Lee, Jia-Wei Wang, Saeko S. Hayashi, Yusuke Tsukamoto, Hsi-Wei Yen, Hyunju Yoo, Sang-Sung Lee, Antonio Chrysostomou, Gwanjeong Kim, Huei-Ru Vivien Chen, Brenda C. Matthews, S. Coude, Qilao Gu, Yasuo Doi, Guoyin Zhang, Tao-Chung Ching, Hiro Saito, Hongchi Wang, Ilse De Looze, Sheng-Yuan Liu, Philippe André, Jihye Hwang, Hiroko Shinnaga, David Berry, Hyeong-Sik Yun, Jane Greaves, Vera Konyves, Do-Young Byun, Ray S. Furuya, Mike Chen, Tim Gledhill, Kyoung Hee Kim, Tetsuya Zenko, Steve Mairs, Jungmi Kwon, Takayoshi Kusune, Chin-Fei Lee, Tetsuya Nagata, Tsuyoshi Inoue, Brendan Retter, Xing Lu, Patrick M. Koch, Yunhee Choi, Chi-Yan Law, Gary A. Fuller, Mehrnoosh Tahani, Takashi Onaka, Pierre Bastien, Xindi Tang, Anna M. M. Scaife, Kohji Tomisaka, Lei Zhu, Sarah Sadavoy, Akimasa Kataoka, Chakali, Eswaraiah [0000-0003-4761-6139], Furuya, Ray S. [0000-0003-0646-8782], Hasegawa, Tetsuo [0000-0003-1853-0184], Ward-Thompson, Derek [0000-0003-1140-2761], Qiu, Keping [0000-0002-5093-5088], Ohashi, Nagayoshi [0000-0003-0998-5064], Pattle, Kate [0000-0002-8557-3582], Sadavoy, Sarah [0000-0001-7474-6874], Hull, Charles L. H. [0000-0002-8975-7573], Berry, David [0000-0001-6524-2447], Doi, Yasuo [0000-0001-8746-6548], Ching, Tao-Chung [0000-0001-8516-2532], Lai, Shih-Ping [0000-0001-5522-486X], Wang, Jia-Wei [0000-0002-6668-974X], Koch, Patrick M. [0000-0003-2777-5861], Kwon, Jungmi [0000-0003-2815-7774], Kwon, Woojin [0000-0003-4022-4132], Bastien, Pierre [0000-0002-0794-3859], Arzoumanian, Doris [0000-0002-1959-7201], Coudé, Simon [0000-0002-0859-0805], Soam, Archana [0000-0002-6386-2906], Fanciullo, Lapo [0000-0001-9930-9240], Yen, Hsi-Wei [0000-0003-1412-893X], Liu, Junhao [0000-0002-4774-2998], Hoang, Thiem [0000-0003-2017-0982], Ping Chen, Wen [0000-0003-0262-272X], Shimajiri, Yoshito [0000-0001-9368-3143], Liu, Tie [0000-0002-5286-2564], Chen, Zhiwei [0000-0003-0849-0692], Li, Hua-bai [0000-0003-2641-9240], Lyo, A-Ran [0000-0002-9907-8427], Hwang, Jihye [0000-0001-7866-2686], Johnstone, Doug [0000-0002-6773-459X], Rao, Ramprasad [0000-0002-1407-7944], Bich Ngoc, Nguyen [0000-0002-5913-5554], Ngoc Diep, Pham [0000-0002-2808-0888], Mairs, Steve [0000-0002-6956-0730], Parsons, Harriet [0000-0002-6327-3423], Tamura, Motohide [0000-0002-6510-0681], Tahani, Mehrnoosh [0000-0001-8749-1436], Vivien Chen, Huei-Ru [0000-0002-9774-1846], Nakamura, Fumitaka [0000-0001-5431-2294], Shinnaga, Hiroko [0000-0001-9407-6775], Tang, Ya-Wen [0000-0002-0675-276X], Cho, Jungyeon [0000-0003-1725-4376], Won Lee, Chang [0000-0002-3179-6334], Inutsuka, Shu-ichiro [0000-0003-4366-6518], Iwasaki, Kazunari [0000-0002-2707-7548], Qian, Lei [0000-0003-0597-0957], Xie, Jinjin [0000-0002-2738-146X], Liu, Hong-Li [0000-0003-3343-9645], Zhang, Chuan-Peng [0000-0002-4428-3183], Zhou, Jianjun [0000-0003-0356-818X], André, Philippe [0000-0002-3413-2293], Liu, Sheng-Yuan [0000-0003-4603-7119], Lu, Xing [0000-0003-2619-9305], Bourke, Tyler L. [0000-0001-7491-0048], Byun, Do-Young [0000-0003-1157-4109], Eden, David [0000-0002-5881-3229], Matthews, Brenda [0000-0003-3017-9577], Fissel, Laura M. [0000-0002-4666-609X], Kim, Kee-Tae [0000-0003-2412-7092], Lee, Chin-Fei [0000-0002-3024-5864], Kim, Jongsoo [0000-0002-1229-0426], Pyo, Tae-Soo [0000-0002-3273-0804], Chrysostomou, Antonio [0000-0002-9583-8644], Jung Chung, Eun [0000-0003-0014-1527], Ngoc Tram, Le [0000-0002-6488-8227], Franzmann, Erica [0000-0003-2142-0357], Friberg, Per [0000-0002-8010-8454], Friesen, Rachel [0000-0001-7594-8128], Fuller, Gary [0000-0001-8509-1818], Gledhill, Tim [0000-0002-2859-4600], Graves, Sarah [0000-0001-9361-5781], Griffin, Matt [0000-0002-0033-177X], Gu, Qilao [0000-0002-2826-1902], Hatchell, Jennifer [0000-0002-4870-2760], Houde, Martin [0000-0003-4420-8674], Kawabata, Koji [0000-0001-6099-9539], Jeong, Il-Gyo [0000-0002-5492-6832], Kang, Ji-hyun [0000-0001-7379-6263], Kang, Sung-ju [0000-0002-5004-7216], Kang, Miju [0000-0002-5016-050X], Kataoka, Akimasa [0000-0003-4562-4119], Kemper, Francisca [0000-0003-2743-8240], Rawlings, Mark [0000-0002-6529-202X], Rawlings, Jonathan [0000-0001-5560-1303], Richer, John [0000-0002-9693-6860], Rigby, Andrew [0000-0002-3351-2200], Savini, Giorgio [0000-0003-4449-9416], Scaife, Anna [0000-0002-5364-2301], Kim, Gwanjeong [0000-0003-2011-8172], Hee Kim, Kyoung [0000-0001-9597-7196], Kim, Mi-Ryang [0000-0002-1408-7747], Kirchschlager, Florian [0000-0002-3036-0184], Kirk, Jason [0000-0002-4552-7477], Kobayashi, Masato I. N. [0000-0003-3990-1204], Konyves, Vera [0000-0002-3746-1498], Kusune, Takayoshi [0000-0002-9218-9319], Lacaille, Kevin [0000-0001-9870-5663], Law, Chi-Yan [0000-0003-1964-970X], Lee, Sang-Sung [0000-0002-6269-594X], Lee, Yong-Hee [0000-0001-6047-701X], Matsumura, Masafumi [0000-0002-6906-0103], Moriarty-Schieven, Gerald [0000-0002-0393-7822], Nagata, Tetsuya [0000-0001-9264-9015], Onaka, Takashi [0000-0002-8234-6747], Park, Geumsook [0000-0001-8467-3736], Tang, Xindi [0000-0002-4154-4309], Tomisaka, Kohji [0000-0003-2726-0892], Viti, Serena [0000-0001-8504-8844], Wang, Hongchi [0000-0003-0746-7968], Yoo, Hyunju [0000-0002-8578-1728], Zhang, Yapeng [0000-0002-5102-2096], Falle, Sam [0000-0002-9829-0426], Robitaille, Jean-François [0000-0001-5079-8573], Apollo - University of Cambridge Repository, Eswaraiah, Chakali [0000-0003-4761-6139], Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)

Subjects
low mass stars, 010504 meteorology & atmospheric sciences, Continuum (design consultancy), AXISYMMETRICAL CLOUD CORES, Astrophysics, F500, MOLECULAR CLOUD, IMAGING POLARIMETRY, 01 natural sciences, AMBIPOLAR-DIFFUSION, STAR-FORMATION, interstellar magnetic fields, Protein filament, CONTRACTION, 0103 physical sciences, SCUBA-2, COLLAPSE, 010303 astronomy & astrophysics, James Clerk Maxwell Telescope, 0105 earth and related environmental sciences, dust continuum emission, polarimetry, Physics, Ambipolar diffusion, Star formation, F510, dense interstellar clouds, Astronomy and Astrophysics, GOULD BELT, Magnetic flux, Magnetic field, DARK CLOUDS, Core (optical fiber), Physics and Astronomy, [SDU]Sciences of the Universe [physics], Space and Planetary Science
Abstract

We have obtained sensitive dust continuum polarization observations at 850 μm in the B213 region of Taurus using POL-2 on SCUBA-2 at the James Clerk Maxwell Telescope as part of the B-fields in STar-forming Region Observations (BISTRO) survey. These observations allow us to probe magnetic field (B-field) at high spatial resolution (∼2000 au or ∼0.01 pc at 140 pc) in two protostellar cores (K04166 and K04169) and one prestellar core (Miz-8b) that lie within the B213 filament. Using the Davis–Chandrasekhar–Fermi method, we estimate the B-field strengths in K04166, K04169, and Miz-8b to be 38 ± 14, 44 ± 16, and 12 ± 5 μG, respectively. These cores show distinct mean B-field orientations. The B-field in K04166 is well ordered and aligned parallel to the orientations of the core minor axis, outflows, core rotation axis, and large-scale uniform B-field, in accordance with magnetically regulated star formation via ambipolar diffusion taking place in K04166. The B-field in K04169 is found to be ordered but oriented nearly perpendicular to the core minor axis and large-scale B-field and not well correlated with other axes. In contrast, Miz-8b exhibits a disordered B-field that shows no preferred alignment with the core minor axis or large-scale field. We found that only one core, K04166, retains a memory of the large-scale uniform B-field. The other two cores, K04169 and Miz-8b, are decoupled from the large-scale field. Such a complex B-field configuration could be caused by gas inflow onto the filament, even in the presence of a substantial magnetic flux.

Published
2021
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9. Observations of magnetic fields surrounding LkH$\alpha$ 101 taken by the BISTRO survey with JCMT-POL-2

Author

Fumitaka Nakamura, Lapo Fanciullo, Eun Jung Chung, Yan Duan, Sophia Dai, Saeko S. Hayashi, Sven Van Loo, Dalei Li, Nicolas Peretto, Ray S. Furuya, Miju Kang, Tyler Bourke, Mark G. Rawlings, John Richer, Archana Soam, Kee-Tae Kim, Anna M. M. Scaife, Kohji Tomisaka, Jason M. Kirk, Hiroko Shinnaga, Anthony Peter Whitworth, David Berry, Chakali Eswaraiah, Le Ngoc Tram, Masumichi Seta, Serena Viti, Geumsook Park, Sheng-Yuan Liu, Nagayoshi Ohashi, Antonio Chrysostomou, Yunhee Choi, Tsuyoshi Inoue, Tae-Soo Pyo, Hongchi Wang, Pham Ngoc Diep, Erica Franzmann, Matthew Joseph Griffin, Francisca Kemper, Kyoung Hee Kim, Tetsuo Hasegawa, Hiro Saito, C. Darren Dowell, Philippe André, Chuan-Peng Zhang, Yong-Hee Lee, Sung-ju Kang, Sam Falle, Mike Chen, Gary A. Fuller, Jongsoo Kim, Chi-Yan Law, Mi-Ryang Kim, Tetsuya Zenko, Thiem Hoang, Tim Gledhill, A-Ran Lyo, Gerald Moriarty-Schieven, Nguyen Bich Ngoc, Takashi Onaka, Pierre Bastien, Motohide Tamura, Harriet Parsons, Hua-bai Li, Takayoshi Kusune, Jungmi Kwon, Xindi Tang, Zhiwei Chen, Tetsuya Nagata, Chin-Fei Lee, Brendan Retter, Guoyin Zhang, Martin Houde, Ji-hyun Kang, Jason Fiege, Il-Gyo Jeong, James Di Francesco, Jane Greaves, Vera Konyves, Do-Young Byun, Junhao Liu, Chang Won Lee, Jia-Wei Wang, Qilao Gu, Patrick M. Koch, Kate Pattle, Shu-ichiro Inutsuka, Derek Ward-Thompson, Florian Kirchschlager, Doris Arzoumanian, Hyeong-Sik Yun, Jianjun Zhou, Lei Zhu, Yusuke Tsukamoto, Charles L. H. Hull, Koji S. Kawabata, Minho Choi, Hyeseung Lee, Yasuo Doi, Kevin Lacaille, Brenda C. Matthews, Ilseung Han, Per Friberg, S. Coude, Jennifer Hatchell, Ramprasad Rao, Di Li, Jihye Hwang, Jean-François Robitaille, L. M. Fissel, Jonathan Rawlings, Gwanjeong Kim, Huei-Ru Vivien Chen, Sarah Sadavoy, Giorgio Savini, Yapeng Zhang, Shih-Ping Lai, Akimasa Kataoka, Xing Lu, Doug Johnstone, Steve Mairs, Andrew Rigby, Mehrnoosh Tahani, Masato I. N. Kobayashi, Hsi-Wei Yen, Hyunju Yoo, Tie Liu, Woojin Kwon, S. L. Kim, Hao-Yuan Duan, Hong-Li Liu, Sang-Sung Lee, Jinjin Xie, Masafumi Matsumura, Tao-Chung Ching, David Eden, Ilse De Looze, Jeong-Eun Lee, S. P. S. Eyres, Rachel Friesen, Jinghua Yuan, Keping Qiu, Sarah Graves, Jungyeon Cho, Wen Ping Chen, Hiroyuki Nakanishi, Y. Shimajiri, Lei Qian, Kazunari Iwasaki, and Ya-Wen Tang

Subjects
Physics, 010308 nuclear & particles physics, Star formation, Molecular cloud, Astronomy and Astrophysics, molecular clouds, Astrophysics, F500, Polarization (waves), 01 natural sciences, Astrophysics - Astrophysics of Galaxies, star formation, Redshift, interstellar magnetic fields, Magnetic field, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 0103 physical sciences, Gravitational collapse, Radiative transfer, 010303 astronomy & astrophysics, James Clerk Maxwell Telescope, Astrophysics::Galaxy Astrophysics
Abstract

We report the first high spatial resolution measurement of magnetic fields surrounding LkH$\alpha$ 101, a part of the Auriga-California molecular cloud. The observations were taken with the POL-2 polarimeter on the James Clerk Maxwell Telescope within the framework of the B-fields In Star-forming Region Observations (BISTRO) survey. Observed polarization of thermal dust emission at 850 $\mu$m is found to be mostly associated with the red-shifted gas component of the cloud. The magnetic field displays a relatively complex morphology. Two variants of the Davis-Chandrasekhar-Fermi method, unsharp masking and structure function, are used to calculate the strength of magnetic fields in the plane of the sky, yielding a similar result of $B_{\rm POS}\sim 115$ $\mathrm{\mu}$G. The mass-to-magnetic-flux ratio in critical value units, $\lambda\sim0.3$, is the smallest among the values obtained for other regions surveyed by POL-2. This implies that the LkH$\alpha$ 101 region is sub-critical and the magnetic field is strong enough to prevent gravitational collapse. The inferred $\delta B/B_0\sim 0.3$ implies that the large scale component of the magnetic field dominates the turbulent one. The variation of the polarization fraction with total emission intensity can be fitted by a power-law with an index of $\alpha=0.82\pm0.03$, which lies in the range previously reported for molecular clouds. We find that the polarization fraction decreases rapidly with proximity to the only early B star (LkH$\alpha$ 101) in the region. The magnetic field tangling and the joint effect of grain alignment and rotational disruption by radiative torques are potential of explaining such a decreasing trend., Comment: 25 pages, 19 figures, Accepted for publication in The Astrophysical Journal

Published
2020

10. The JCMT BISTRO Survey: Magnetic Fields Associated with a Network of Filaments in NGC 1333

Author

Jason Fiege, Di Li, Fumitaka Nakamura, Patrick M. Koch, J. S. Richer, Matthew Joseph Griffin, Jason M. Kirk, Miju Kang, Geumsook Park, Nagayoshi Ohashi, Erica Franzmann, Tetsuo Hasegawa, Tetsuya Zenko, Jia-Wei Wang, Qilao Gu, Brendan Retter, Martin Houde, Per Friberg, Junhao Liu, Tsuyoshi Inoue, Keping Qiu, Sam Falle, Minho Choi, Hao Yuan Duan, Philippe André, Jennifer Hatchell, Kate Pattle, Charles L. H. Hull, Sven Van Loo, Gary A. Fuller, Hsi-Wei Yen, Hyunju Yoo, Ramprasad Rao, Yasuo Doi, Takayoshi Kusune, Hiro Saito, Koji S. Kawabata, Kevin Lacaille, Mark G. Rawlings, Takashi Onaka, Pierre Bastien, Woojin Kwon, Mi Ryang Kim, S. P. S. Eyres, Chin-Fei Lee, Tae-Soo Pyo, Giorgio Savini, Yapeng Zhang, Serena Viti, Ya-Wen Tang, Doug Johnstone, Masumichi Seta, Ray S. Furuya, Francisca Kemper, Huei Ru Vivien Chen, Jihye Hwang, Saeko S. Hayashi, Yong-Hee Lee, S. L. Kim, Zhiwei Chen, Sang-Sung Lee, Shih-Ping Lai, Hongchi Wang, Masato I. N. Kobayashi, Lei Qian, Wen Ping Chen, Sung-ju Kang, Chuan Peng Zhang, Andrew Rigby, Shu-ichiro Inutsuka, Kazunari Iwasaki, Thiem Hoang, C. Darren Dowell, Yoshihiro Kanamori, Kyoung Hee Kim, Eun Jung Chung, Masafumi Matsumura, Mehrnoosh Tahani, Chakali Eswaraiah, Michael Chun Yuan Chen, A. Ran Lyo, Gerald Moriarty-Schieven, Ilse De Looze, Jeong-Eun Lee, James Di Francesco, Yusuke Tsukamoto, Yunhee Choi, Dalei Li, Tao Chung Ching, Hua-bai Li, Jane Greaves, Hong-Li Liu, Archana Soam, Vera Konyves, Do-Young Byun, Anthony Peter Whitworth, Brenda C. Matthews, Ilseung Han, Motohide Tamura, Rachel Friesen, Kee-Tae Kim, Simon Coudé, Derek Ward-Thompson, Pham Ngoc Diep, Jianjun Zhou, Gwanjeong Kim, Hyeseung Lee, Anna M. M. Scaife, J.-F. Robitaille, Jinghua Yuan, Y. Shimajiri, Sheng-Yuan Liu, Kohji Tomisaka, Lei Zhu, Hyeong Sik Yun, Lapo Fanciullo, J. H. Kang, Harriet Parsons, Tie Liu, Jongsoo Kim, Tim Gledhill, Nicolas Peretto, Sarah Graves, Sarah Sadavoy, Steve Mairs, Jungmi Kwon, Tetsuya Nagata, Chang Won Lee, Jungyeon Cho, Hiroyuki Nakanishi, Akimasa Kataoka, Chi Yan Law, Il Gyo Jeong, Antonio Chrysostomou, Doris Arzoumanian, Guoyin Zhang, Hiroko Shinnaga, and David Berry

Subjects
Physics, 010504 meteorology & atmospheric sciences, Plane (geometry), Star formation, Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Magnetic field, Protein filament, Interstellar medium, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, 010303 astronomy & astrophysics, Local field, James Clerk Maxwell Telescope, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences
Abstract

We present new observations of the active star formation region NGC 1333 in the Perseus molecular cloud complex from the James Clerk Maxwell Telescope B -Fields In Star-forming Region Observations (BISTRO) survey with the POL-2 instrument. The BISTRO data cover the entire NGC 1333 complex (∼1.5 pc × 2 pc) at 0.02 pc resolution and spatially resolve the polarized emission from individual filamentary structures for the first time. The inferred magnetic field structure is complex as a whole, with each individual filament aligned at different position angles relative to the local field orientation. We combine the BISTRO data with low- and high- resolution data derived from Planck and interferometers to study the multiscale magnetic field structure in this region. The magnetic field morphology drastically changes below a scale of ∼1 pc and remains continuous from the scales of filaments (∼0.1 pc) to that of protostellar envelopes (∼0.005 pc or ∼1000 au). Finally, we construct simple models in which we assume that the magnetic field is always perpendicular to the long axis of the filaments. We demonstrate that the observed variation of the relative orientation between the filament axes and the magnetic field angles are well reproduced by this model, taking into account the projection effects of the magnetic field and filaments relative to the plane of the sky. These projection effects may explain the apparent complexity of the magnetic field structure observed at the resolution of BISTRO data toward the filament network., Erratum published in volume 899, issue 1, 5 p., April 10 2021. DOI: 10.3847/1538-4357/abf2b3

Published
2020

11. Erratum: 'The JCMT BISTRO Survey: Magnetic Fields Associated with a Network of Filaments in NGC 1333' (2020, ApJ, 899, 28)

Author

Il Gyo Jeong, Fumitaka Nakamura, Jason M. Kirk, Geumsook Park, Nagayoshi Ohashi, Erica Franzmann, Jongsoo Kim, Doris Arzoumanian, Saeko S. Hayashi, Thiem Hoang, Hongchi Wang, Simon Coudé, Pham Ngoc Diep, Tae-Soo Pyo, Chang Won Lee, Sven Van Loo, Chakali Eswaraiah, Sung-ju Kang, Jihye Hwang, Tao Chung Ching, Per Friberg, Derek Ward-Thompson, Martin Houde, Philippe André, C. Darren Dowell, Francisca Kemper, Sarah Graves, Hsi-Wei Yen, Hyunju Yoo, Hyeseung Lee, Jianjun Zhou, Gerald Moriarty-Schieven, Jason Fiege, Harriet Parsons, Yong-Hee Lee, Jennifer Hatchell, Ramprasad Rao, Yasuo Doi, Y. Shimajiri, Mi Ryang Kim, John Richer, Kee-Tae Kim, Motohide Tamura, Di Li, Chuan Peng Zhang, Woojin Kwon, Mark G. Rawlings, Tim Gledhill, Jia-Wei Wang, Anna M. M. Scaife, J.-F. Robitaille, Kohji Tomisaka, Hong-Li Liu, S. L. Kim, Jungyeon Cho, Masumichi Seta, J. H. Kang, Mehrnoosh Tahani, Tie Liu, A. Ran Lyo, Tetsuya Zenko, Sang-Sung Lee, Shu-ichiro Inutsuka, Lapo Fanciullo, Hao Yuan Duan, Hua-bai Li, Tsuyoshi Inoue, Hiroyuki Nakanishi, Nicolas Peretto, Akimasa Kataoka, Patrick M. Koch, Doug Johnstone, Ya-Wen Tang, Eun Jung Chung, Shih-Ping Lai, Masato I. N. Kobayashi, Takayoshi Kusune, Chin-Fei Lee, Steve Mairs, Jungmi Kwon, Tetsuya Nagata, Giorgio Savini, Ray S. Furuya, James Di Francesco, Brenda C. Matthews, Dalei Li, Lei Qian, Zhiwei Chen, Michael Chun-Yuan Chen, Ilseung Han, Kate Pattle, Jane Greaves, Miju Kang, Kazunari Iwasaki, Archana Soam, Anthony Peter Whitworth, Kyoung Hee Kim, Charles L. H. Hull, Chi Yan Law, Koji S. Kawabata, Kevin Lacaille, Vera Konyves, Do-Young Byun, Yoshihiro Kanamori, Huei Ru Vivien Chen, Qilao Gu, Masafumi Matsumura, Hyeong Sik Yun, Sheng-Yuan Liu, Lei Zhu, Yunhee Choi, Ilse De Looze, Jeong-Eun Lee, Yusuke Tsukamoto, Yapeng Zhang, Andrew Rigby, Brendan Retter, Sarah Sadavoy, Gwanjeong Kim, Antonio Chrysostomou, Junhao Liu, Minho Choi, Gary A. Fuller, Guoyin Zhang, Takashi Onaka, Pierre Bastien, Hiroko Shinnaga, S. P. S. Eyres, David Berry, Rachel Friesen, Matthew Joseph Griffin, Tetsuo Hasegawa, Sam Falle, Serena Viti, Hiro Saito, Jinghua Yuan, Wen Ping Chen, and Keping Qiu

Subjects
Physics, Brewster's angle, Magnetic structure, Field (physics), F510, Molecular cloud, Astronomy and Astrophysics, Astrophysics, Position angle, Magnetic field, symbols.namesake, Space and Planetary Science, Magnitude (astronomy), symbols, Planck
Abstract

In the published article, we presented high-resolution polarimetry data obtained by using JCMT SCUBA-2/POL-2, and compared them with the larger-scale magnetic structure observed by Planck (Planck Collaboration et al. 2020). There was a miscalculation in the analysis of the Planck data for comparison, and the mean position angle of the Planck magnetic field should be corrected from -40° ± 7° to -48° ± 6°. Thus, we replace the descriptions in the published article as follows. In Section 4.2, paragraph 3, the second sentence should read: "The differences between the orientations of IRAS 4A, IRAS 4B, and IRAS 2A are not statistically significant, but they do show significantly different orientations from those of the global B-field observed by Planck (-48° ± 6°; Section 4.1)." In Section 4.1, paragraph 3, the second line should read: "The Planck B-field orientation shows a smoothly and slowly varying field distribution with a position angle of -48° ± 6° in our observed NGC 1333 area." Accordingly, we replace Figures 4, 5, 9, 10, and 17 to reflect the correct Planck data. As described above, this error of modest magnitude is related only to our derivation of the Planck polarization angle, and the JCMT observation results are unaffected. Therefore, all conclusions drawn in the published article are unchanged even after the above correction is applied. The 1 pc scale magnetic field observed by Planck shows a smooth distribution, and the interstellar magnetic field in molecular clouds increases the complexity significantly on the scale of less than 1 pc.

Published
2021

12. JCMT BISTRO Survey: Magnetic Fields within the Hub-filament Structure in IC 5146

Author

Jia-Wei Wang, Shih-Ping Lai, Chakali Eswaraiah, Kate Pattle, James Di Francesco, Doug Johnstone, Patrick M. Koch, Tie Liu, Motohide Tamura, Ray S. Furuya, Takashi Onaka, Derek Ward-Thompson, Archana Soam, Kee-Tae Kim, Chang Won Lee, Chin-Fei Lee, Steve Mairs, Doris Arzoumanian, Gwanjeong Kim, Thiem Hoang, Jihye Hwang, Sheng-Yuan Liu, David Berry, Pierre Bastien, Tetsuo Hasegawa, Woojin Kwon, Keping Qiu, Philippe André, Yusuke Aso, Do-Young Byun, Huei-Ru Chen, Michael C. Chen, Wen Ping Chen, Tao-Chung Ching, Jungyeon Cho, Minho Choi, Antonio Chrysostomou, Eun Jung Chung, Simon Coudé, Yasuo Doi, C. Darren Dowell, Emily Drabek-Maunder, Hao-Yuan Duan, Stewart P. S. Eyres, Sam Falle, Lapo Fanciullo, Jason Fiege, Erica Franzmann, Per Friberg, Rachel K. Friesen, Gary Fuller, Tim Gledhill, Sarah F. Graves, Jane S. Greaves, Matt J. Griffin, Qilao Gu, Ilseung Han, Jennifer Hatchell, Saeko S. Hayashi, Wayne Holland, Martin Houde, Tsuyoshi Inoue, Shu-ichiro Inutsuka, Kazunari Iwasaki, Il-Gyo Jeong, Yoshihiro Kanamori, Ji-hyun Kang, Miju Kang, Sung-ju Kang, Akimasa Kataoka, Koji S. Kawabata, Francisca Kemper, Jongsoo Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Jason M. Kirk, Masato I. N. Kobayashi, Vera Konyves, Jungmi Kwon, Kevin M. Lacaille, Hyeseung Lee, Jeong-Eun Lee, Sang-Sung Lee, Yong-Hee Lee, Dalei Li, Di Li, Hua-bai Li, Hong-Li Liu, Junhao Liu, A-Ran Lyo, Masafumi Matsumura, Brenda C. Matthews, Gerald H. Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Geumsook Park, Harriet Parsons, Enzo Pascale, Nicolas Peretto, Andy Pon, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Mark G. Rawlings, Brendan Retter, John Richer, Andrew Rigby, Jean-François Robitaille, Sarah Sadavoy, Hiro Saito, Giorgio Savini, Anna M. M. Scaife, Masumichi Seta, Hiroko Shinnaga, Ya-Wen Tang, Kohji Tomisaka, Yusuke Tsukamoto, Sven van Loo, Hongchi Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Hyeong-Sik Yun, Tetsuya Zenko, Chuan-Peng Zhang, Guoyin Zhang, Ya-Peng Zhang, Jianjun Zhou, and Lei Zhu

Subjects
individual objects (IC 5146) [ISM], 010504 meteorology & atmospheric sciences, FOS: Physical sciences, ISM [radio continuum], Probability density function, Astrophysics, 01 natural sciences, law.invention, Protein filament, ISM: individual objects (IC 5146), ISM: magnetic fields, ISM: structure, polarization, radio continuum: ISM, stars: formation, law, 0103 physical sciences, 010303 astronomy & astrophysics, James Clerk Maxwell Telescope, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, formation [stars], Turbulence, F510, Bolometer, magnetic fields [ISM], Astronomy and Astrophysics, Polarimeter, Polarization (waves), Astrophysics - Astrophysics of Galaxies, Magnetic field, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), structure [ISM]
Abstract

We present the 850 $\mu$m polarization observations toward the IC5146 filamentary cloud taken using the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and its associated polarimeter (POL-2), mounted on the James Clerk Maxwell Telescope (JCMT), as part of the B-fields In STar forming Regions Observations (BISTRO). This work is aimed at revealing the magnetic field morphology within a core-scale ($\lesssim 1.0$ pc) hub-filament structure (HFS) located at the end of a parsec-scale filament. To investigate whether or not the observed polarization traces the magnetic field in the HFS, we analyze the dependence between the observed polarization fraction and total intensity using a Bayesian approach with the polarization fraction described by the Rice likelihood function, which can correctly describe the probability density function (PDF) of the observed polarization fraction for low signal-to-noise ratio (SNR) data. We find a power-law dependence between the polarization fraction and total intensity with an index of 0.56 in $A_V\sim$ 20--300 mag regions, suggesting that the dust grains in these dense regions can still be aligned with magnetic fields in the IC5146 regions. Our polarization maps reveal a curved magnetic field, possibly dragged by the contraction along the parsec-scale filament. We further obtain a magnetic field strength of 0.5$\pm$0.2 mG toward the central hub using the Davis-Chandrasekhar-Fermi method, corresponding to a mass-to-flux criticality of $\sim$ $1.3\pm0.4$ and an Alfv\'{e}nic Mach number of $, Comment: 24 pages, 15 figures, accepted for publication in ApJ

Published
2019

13. A First Look at BISTRO Observations of The $\rho$ Oph-A core

Author

Jungmi Kwon, Yasuo Doi, Motohide Tamura, Masafumi Matsumura, Kate Pattle, David Berry, Sarah Sadavoy, Brenda C. Matthews, Derek Ward-Thompson, Tetsuo Hasegawa, Ray S. Furuya, Andy Pon, James Di Francesco, Doris Arzoumanian, Saeko S. Hayashi, Koji S. Kawabata, Takashi Onaka, Minho Choi, Miju Kang, Thiem Hoang, Chang Won Lee, Sang-Sung Lee, Hong-Li Liu, Tie Liu, Shu-ichiro Inutsuka, Chakali Eswaraiah, Pierre Bastien, Woojin Kwon, Shih-Ping Lai, Keping Qiu, Simon Coudé, Erica Franzmann, Per Friberg, Sarah F. Graves, Jane S. Greaves, Martin Houde, Doug Johnstone, Jason M. Kirk, Patrick M. Koch, Di Li, Harriet Parsons, Ramprasad Rao, Mark G. Rawlings, Hiroko Shinnaga, Sven van Loo, Yusuke Aso, Do-Young Byun, Huei-Ru Chen, Mike C.-Y. Chen, Wen Ping Chen, Tao-Chung Ching, Jungyeon Cho, Antonio Chrysostomou, Eun Jung Chung, Emily Drabek-Maunder, Stewart P. S. Eyres, Jason Fiege, Rachel K. Friesen, Gary Fuller, Tim Gledhill, Matt J. Griffin, Qilao Gu, Jennifer Hatchell, Wayne Holland, Tsuyoshi Inoue, Kazunari Iwasaki, Il-Gyo Jeong, Ji-hyun Kang, Sung-ju Kang, Francisca Kemper, Gwanjeong Kim, Jongsoo Kim, Kee-Tae Kim, Kyoung Hee Kim, Mi-Ryang Kim, Shinyoung Kim, Kevin M. Lacaille, Jeong-Eun Lee, Dalei Li, Hua-bai Li, Junhao Liu, Sheng-Yuan Liu, A-Ran Lyo, Steve Mairs, Gerald H. Moriarty-Schieven, Fumitaka Nakamura, Hiroyuki Nakanishi, Nagayoshi Ohashi, Nicolas Peretto, Tae-Soo Pyo, Lei Qian, Brendan Retter, John Richer, Andrew Rigby, Jean-Franois Robitaille, Giorgio Savini, Anna M. M. Scaife, Archana Soam, Ya-Wen Tang, Kohji Tomisaka, Hongchi Wang, Jia-Wei Wang, Anthony P. Whitworth, Hsi-Wei Yen, Hyunju Yoo, Jinghua Yuan, Chuan-Peng Zhang, Guoyin Zhang, Jianjun Zhou, Lei Zhu, Philippe André, C. Darren Dowell, Sam Falle, Yusuke Tsukamoto, Takao Nakagawa, Yoshihiro Kanamori, Akimasa Kataoka, Masato I. N. Kobayashi, Tetsuya Nagata, Hiro Saito, Masumichi Seta, and Tetsuya Zenko

Subjects
010504 meteorology & atmospheric sciences, ISM: structure, media_common.quotation_subject, Polarimetry, ISM [radio continuum], Astrophysics, individual objects (Ophiuchi) [ISM], Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, circumstellar matter, law.invention, ISM: individual objects (Ophiuchi), law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, media_common, Physics, F990, polarization, formation [stars], Bolometer, Polarimeter, Astronomy and Astrophysics, Polarization (waves), Astrophysics - Astrophysics of Galaxies, Magnetic field, radio, Wavelength, Sky, Space and Planetary Science, Degree of polarization, structure [ISM]
Abstract

著者人数: 122名 (所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 權, 靜美; 中西, 裕之; 中川, 貴雄）, Accepted: 2018-03-26, 資料番号: SA1170332000

Published
2018

14. Magnetic fields towards Ophiuchus-b derived from scuba-2 polarization measurements

Author

Patrick M. Koch, Gary A. Fuller, Takashi Onaka, Pierre Bastien, Archana Soam, Philippe André, Jihye Hwang, Tetsuya Zenko, Tim Gledhill, Jia-Wei Wang, Rachel Friesen, Andy Pon, Sarah Graves, Jongsoo Kim, Steve Mairs, Jungmi Kwon, Tetsuya Nagata, Giorgio Savini, Hiroko Shinnaga, Kate Pattle, Wen Ping Chen, Yusuke Tsukamoto, Chang Won Lee, Hsi-Wei Yen, Shih-Ping Lai, John Richer, Thiem Hoang, Kee-Tae Kim, Jungyeon Cho, Sarah Sadavoy, Doris Arzoumanian, Kevin Lacaille, Hiroyuki Nakanishi, David Berry, Dalei Li, Hyeseung Lee, Hong-Li Liu, Gwanjeong Kim, Sang-Sung Lee, C. Darren Dowell, Anthony Peter Whitworth, Woojin Kwon, Mi-Ryang Kim, Derek Ward-Thompson, Ray S. Furuya, Sheng-Yuan Liu, Sung-ju Kang, Jianjun Zhou, Eun Jung Chung, Hiro Saito, Emily Drabek-Maunder, Brenda C. Matthews, Motohide Tamura, Koji S. Kawabata, Junhao Liu, Yoshihiro Kanamori, Ya-Wen Tang, Minho Choi, Chakali Eswaraiah, Saeko S. Hayashi, Tae-Soo Pyo, Keping Qiu, Francisca Kemper, Shu-ichiro Inutsuka, Lei Qian, James Di Francesco, Shinyoung Kim, Tie Liu, Tsuyoshi Inoue, Chuan-Peng Zhang, Yusuke Aso, Matthew Joseph Griffin, Kazunari Iwasaki, S. P. S. Eyres, Miju Kang, Jane Greaves, Tetsuo Hasegawa, Anna M. M. Scaife, Kohji Tomisaka, Do-Young Byun, J. F. Robitaille, Sam Falle, Jinghua Yuan, Masafumi Matsumura, Nicolas Peretto, Antonio Chrysostomou, Guoyin Zhang, Akimasa Kataoka, Hyunju Yoo, Qilao Gu, Wayne S. Holland, Sven Van Loo, Mark G. Rawlings, Ilseung Han, Simon Coudé, Masumichi Seta, M. Chen, Huei-Ru Chen, Lei Zhu, Harriet Parsons, Yasuo Doi, Hongchi Wang, Ji-hyun Kang, Hua-bai Li, Jason Fiege, Il-Gyo Jeong, Per Friberg, Kyoung Hee Kim, Jennifer Hatchell, Ramprasad Rao, Di Li, Gerald H. Moriarty-Schieven, Doug Johnstone, Brendan Retter, Masato I. N. Kobayashi, Martin Houde, Fumitaka Nakamura, A-Ran Lyo, Jason M. Kirk, Nagayoshi Ohashi, Erica Franzmann, Andrew Rigby, Tao-Chung Ching, and Jeong-Eun Lee

Subjects
Field line, ISM: structure, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, James Clerk Maxwell Telescope, Astrophysics::Galaxy Astrophysics, QB, Physics, polarization, stars: formation, 010308 nuclear & particles physics, Star formation, ISM: individual objects (Ophiuchus), Molecular cloud, Astronomy and Astrophysics, Polarization (waves), Astrophysics - Astrophysics of Galaxies, Magnetic field, radio continuum: ISM, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Ophiuchus, Degree of polarization, Astrophysics::Earth and Planetary Astrophysics
Abstract

著者人数: 124名（所属. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS): 權, 靜美), Accepted: 2018-05-10, 資料番号: SA1180101000

Published
2018

15. GMC Collisions as Triggers of Star Formation. III. Density and Magnetically Regulated Star Formation

Author

Fumitaka Nakamura, David C. Collins, Duncan Christie, Benjamin Wu, Sven Van Loo, and Jonathan C. Tan

Subjects
Physics, 010308 nuclear & particles physics, Turbulence, Star formation, Molecular cloud, Time evolution, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Collision, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Stars, Star cluster, Model parameter, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We study giant molecular cloud (GMC) collisions and their ability to trigger star cluster formation. We further develop our three dimensional magnetized, turbulent, colliding GMC simulations by implementing star formation sub-grid models. Two such models are explored: (1) "Density-Regulated," i.e., fixed efficiency per free-fall time above a set density threshold; (2) "Magnetically-Regulated," i.e., fixed efficiency per free-fall time in regions that are magnetically supercritical. Variations of parameters associated with these models are also explored. In the non-colliding simulations, the overall level of star formation is sensitive to model parameter choices that relate to effective density thresholds. In the GMC collision simulations, the final star formation rates and efficiencies are relatively independent of these parameters. Between non-colliding and colliding cases, we compare the morphologies of the resulting star clusters, properties of star-forming gas, time evolution of the star formation rate (SFR), spatial clustering of the stars, and resulting kinematics of the stars in comparison to the natal gas. We find that typical collisions, by creating larger amounts of dense gas, trigger earlier and enhanced star formation, resulting in 10 times higher SFRs and efficiencies. The star clusters formed from GMC collisions show greater spatial sub-structure and more disturbed kinematics., 22 pages, 10 figures, Accepted for publication in ApJ

Published
2017

16. GMC Collisions as Triggers of Star Formation. II. 3D Turbulent, Magnetized Simulations

Author

Benjamin Wu, Sven Van Loo, Duncan Christie, Jonathan C. Tan, David C. Collins, and Fumitaka Nakamura

Subjects
Physics, 010308 nuclear & particles physics, Adaptive mesh refinement, Turbulence, Star formation, Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Spectral line, Virial theorem, Magnetic field, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Magnetohydrodynamics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

We investigate giant molecular cloud (GMCs) collisions and their ability to induce gravitational instability and thus star formation. This mechanism may be a major driver of star formation activity in galactic disks. We carry out a series of three dimensional, magnetohydrodynamics (MHD), adaptive mesh refinement (AMR) simulations to study how cloud collisions trigger formation of dense filaments and clumps. Heating and cooling functions are implemented based on photo-dissociation region (PDR) models that span the atomic to molecular transition and can return detailed diagnostic information. The clouds are initialized with supersonic turbulence and a range of magnetic field strengths and orientations. Collisions at various velocities and impact parameters are investigated. Comparing and contrasting colliding and non-colliding cases, we characterize morphologies of dense gas, magnetic field structure, cloud kinematic signatures, and cloud dynamics. We present key observational diagnostics of cloud collisions, especially: relative orientations between magnetic fields and density structures, like filaments; $^{13}$CO($J$=2-1), $^{13}$CO($J$=3-2), and $^{12}$CO($J$=8-7) integrated intensity maps and spectra; and cloud virial parameters. We compare these results to observed Galactic clouds., 27 pages, 17 figures, Accepted for publication in ApJ

Published
2016

17. GMC Collisions as Triggers of Star Formation. I. Parameter Space Exploration with 2D Simulations

Author

Sven Van Loo, Jonathan C. Tan, Simon Bruderer, and Benjamin Wu

Subjects
Physics, Star formation, FOS: Physical sciences, Astronomy and Astrophysics, Fluid mechanics, Photodissociation region, Parameter space, Astrophysics - Astrophysics of Galaxies, Magnetic field, Computational physics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Gravitational collapse, Impact parameter, Magnetohydrodynamics, Astrophysics::Galaxy Astrophysics
Abstract

We utilize magnetohydrodynamic (MHD) simulations to develop a numerical model for GMC-GMC collisions between nearly magnetically critical clouds. The goal is to determine if, and under what circumstances, cloud collisions can cause pre-existing magnetically subcritical clumps to become supercritical and undergo gravitational collapse. We first develop and implement new photodissociation region (PDR) based heating and cooling functions that span the atomic to molecular transition, creating a multiphase ISM and allowing modeling of non-equilibrium temperature structures. Then in 2D and with ideal MHD, we explore a wide parameter space of magnetic field strength, magnetic field geometry, collision velocity, and impact parameter, and compare isolated versus colliding clouds. We find factors of ~2-3 increase in mean clump density from typical collisions, with strong dependence on collision velocity and magnetic field strength, but ultimately limited by flux-freezing in 2D geometries. For geometries enabling flow along magnetic field lines, greater degrees of collapse are seen. We discuss observational diagnostics of cloud collisions, focussing on 13CO(J=2-1), 13CO(J=3-2), and 12CO(J=8-7) integrated intensity maps and spectra, which we synthesize from our simulation outputs. We find the ratio of J=8-7 to lower-J emission is a powerful diagnostic probe of GMC collisions., Comment: 22 pages, 23 figures. Accepted for publication in ApJ

Published
2015
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18. Magnetic Fields and Galactic Star Formation Rates

Author

Sam Falle, Jonathan C. Tan, and Sven Van Loo

Subjects
Physics, Star formation, Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Magnetic field, Stars, Star cluster, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Galaxy formation and evolution, Stellar evolution, Astrophysics::Galaxy Astrophysics
Abstract

The regulation of galactic-scale star formation rates (SFRs) is a basic problem for theories of galaxy formation and evolution: which processes are responsible for making observed star formation rates so inefficient compared to maximal rates of gas content divided by dynamical timescale? Here we study the effect of magnetic fields of different strengths on the evolution of giant molecular clouds (GMCs) within a kiloparsec patch of a disk galaxy and resolving scales down to $\simeq0.5\:{\rm{pc}}$. Including an empirically motivated prescription for star formation from dense gas ($n_{\rm{H}}>10^5\:{\rm{cm}^{-3}}$) at an efficiency of 2\% per local free-fall time, we derive the amount of suppression of star formation by magnetic fields compared to the nonmagnetized case. We find GMC fragmentation, dense clump formation and SFR can be significantly affected by the inclusion of magnetic fields, especially in our strongest investigated $B$-field case of $80\:{\rm��}$G. However, our chosen kpc-scale region, extracted from a global galaxy simulation, happens to contain a starbursting cloud complex that is only modestly affected by these magnetic fields and likely requires internal star formation feedback to regulate its SFR., 7 pages, 5 figures. Accepted by ApJ Letters

Published
2014

19. Core and filament formation in magnetized, self-gravitating isothermal layers

Author

Qizhou Zhang, Eric Keto, and Sven Van Loo

Subjects
Physics, Condensed matter physics, Turbulence, FOS: Physical sciences, Astronomy and Astrophysics, Scale height, Power law, Magnetic field, Protein filament, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Thermal, Gravitational collapse, Perpendicular, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We examine the role of the gravitational instability in an isothermal, self-gravitating layer threaded by magnetic fields on the formation of filaments and dense cores. Using numerical simulation we follow the non-linear evolution of a perturbed equilibrium layer. The linear evolution of such a layer is described in the analytic work of Nagai et al (1998). We find that filaments and dense cores form simultaneously. Depending on the initial magnetic field, the resulting filaments form either a spiderweb-like network (for weak magnetic fields) or a network of parallel filaments aligned perpendicular to the magnetic field lines (for strong magnetic fields). Although the filaments are radially collapsing, the density profile of their central region (up to the thermal scale height) can be approximated by a hydrodynamical equilibrium density structure. Thus, the magnetic field does not play a significant role in setting the density distribution of the filaments. The density distribution outside of the central region deviates from the equilibrium. The radial column density distribution is then flatter than the expected power law of $r^{-4}$ and similar to filament profiles observed with Herschel. Our results does not explain the near constant filament width of $\sim 0.1$pc. However, our model does not include turbulent motions. It is expected that accretion-driven amplification of these turbulent motions provides additional support within the filaments against gravitational collapse. Finally, we interpret the filamentary network of the massive star forming complex G14.225-0.506 in terms of the gravitational instability model and find that the properties of the complex are consistent with being formed out of an unstable layer threaded by a strong, parallel magnetic field., Comment: Accepted by ApJ, 14 pages, 22 figures

Published
2014

20. Kiloparsec-Scale Simulations of Star Formation in Disk Galaxies III. Structure and Dynamics of Filaments and Clumps in Giant Molecular Clouds

Author

Sven Van Loo, Jonathan C. Tan, and Michael J. Butler

Subjects
Physics, Star formation, Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Galactic plane, Galaxy, Protein filament, Star cluster, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Disc, Mass fraction, Astrophysics::Galaxy Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR)
Abstract

We present hydrodynamic simulations of self-gravitating dense gas in a galactic disk, exploring scales ranging from 1 kpc down to $\sim 0.1$~pc. Our primary goal is to understand how dense filaments form in Giant Molecular Clouds (GMCs). These structures, often observed as Infrared Dark Clouds (IRDCs) in the Galactic plane, are thought to be the precursors to massive stars and star clusters, so their formation may be the rate limiting step controlling global star formation rates in galactic systems as described by the Kennicutt-Schmidt relation. Our study follows on from Van Loo et al. (2013, Paper I), which carried out simulations to 0.5~pc resolution and examined global aspects of the formation of dense gas clumps and the resulting star formation rate. Here, using our higher resolution, we examine the detailed structural, kinematic and dynamical properties of dense filaments and clumps, including mass surface density ($\Sigma$) probability distribution functions, filament mass per unit length and its dispersion, lateral $\Sigma$ profiles, filament fragmentation, filament velocity gradients and infall, and degree of filament and clump virialization. Where possible, these properties are compared to observations of IRDCs. By many metrics, especially too large mass fractions of high $\Sigma>1\:{\rm g\:cm^{-2}}$ material, too high mass per unit length dispersion due to dense clump formation, too high velocity gradients and too high velocity dispersion for a given mass per unit length, the simulated filaments differ from observed IRDCs. We thus conclude that IRDCs do not form from global fast collapse of GMCs. Rather, we expect IRDC formation and collapse is slowed significantly by the influence of dynamically important magnetic fields, which may thus play a crucial role in regulating galactic star formation rates., Comment: 26 pages, 15 figures, accepted to ApJ

Published
2014
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21. Kiloparsec-scale simulations of star formation in disk galaxies. I. the unmagnetized and zero-feedback limit

Author

Michael J. Butler, Jonathan C. Tan, and Sven Van Loo

Subjects
Physics, Star formation, Molecular cloud, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrophysics - Astrophysics of Galaxies, Galaxy, Virial theorem, Star cluster, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Thermal, Disc, 010306 general physics, 010303 astronomy & astrophysics, Order of magnitude, Astrophysics::Galaxy Astrophysics
Abstract

We present hydrodynamic simulations of the evolution of self-gravitating dense gas on scales of 1 kiloparsec down to < parsec in a galactic disk, designed to study dense clump formation from giant molecular clouds (GMCs). These structures are expected to be the precursors to star clusters and this process may be the rate limiting step controling star formation rates in galactic systems as described by the Kennicutt-Schmidt relation. We follow the thermal evolution of the gas down to ~5K using extinction-dependent heating and cooling functions. We do not yet include magnetic fields or localized stellar feedback, so the evolution of the GMCs and clumps is determined solely by self-gravity balanced by thermal and turbulent pressure support and the large scale galactic shear. While cloud structures and densities change significantly during the simulation, GMC virial parameters remain mostly above unity for time scales exceeding the free-fall time of GMCs indicating that energy from galactic shear and large-scale cloud motions continuously cascades down to and within the GMCs. We implement star formation at a slow, inefficient rate of 2% per local free-fall time, but even this yields global star formation rates that are about two orders of magnitude larger than the observed Kennicutt-Schmidt relation due to over-production of dense gas clumps. We expect a combination of magnetic support and localized stellar feedback is required to inhibit dense clump formation to ~1% of the rate that results from the nonmagnetic, zero-feedback limit., Accepted by ApJ, 14 pages and 16 figures

Published
2013

22. Molecular Clouds: Internal Properties, Turbulence, Star Formation and Feedback

Author

Jonathan C. Tan, Sven Van Loo, and Suzanne N. Shaske

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Star formation, Turbulence, Molecular cloud, Theoretical models, FOS: Physical sciences, Astronomy and Astrophysics, Plasma, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, Galaxy, Stars, Star cluster, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

All stars are born in molecular clouds, and most in giant molecular clouds (GMCs), which thus set the star formation activity of galaxies. We first review their observed properties, including measures of mass surface density, Sigma, and thus mass, M. We discuss cloud dynamics, concluding most GMCs are gravitationally bound. Star formation is highly clustered within GMCs, but overall is very inefficient. We compare properties of star-forming clumps with those of young stellar clusters (YSCs). The high central densities of YSCs may result via dynamical evolution of already-formed stars during and after star cluster formation. We discuss theoretical models of GMC evolution, especially addressing how turbulence is maintained, and emphasizing the importance of GMC collisions. We describe how feedback limits total star formation efficiency, epsilon, in clumps. A turbulent and clumpy medium allows higher epsilon, permitting formation of bound clusters even when escape speeds are less than the ionized gas sound speed., Comment: Invited review, IAU Symp. 292 Molecular Gas, Dust, and Star Formation in Galaxies

Published
2012
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