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1. Protostellar Disk Formation Regimes: Angular Momentum Conservation versus Magnetic Braking

Author

Hsi-Wei Yen and Yueh-Ning Lee

Subjects
Star formation, Protostars, Circumstellar disks, Magnetohydrodynamics, Astrophysics, QB460-466
Abstract

Protostellar disks around young protostars exhibit diverse properties, with their radii ranging from less than ten to several hundred astronomical units. To investigate the mechanisms shaping this disk radius distribution, we compiled a sample of 27 Class 0 and I single protostars with resolved disks and dynamically determined protostellar masses from the literature. Additionally, we derived the radial profile of the rotational-to-gravitational-energy ratio in dense cores from the observed specific angular momentum profiles in the literature. Using these observed protostellar masses and rotational energy profile, we computed theoretical disk radii from the hydrodynamic and nonideal magnetohydrodynamic (MHD) models in Y.-N. Lee et al. and generated synthetic samples to compare with the observations. In our theoretical model, the disk radii are determined by hydrodynamics when the central protostar+disk mass is low. After the protostars and disks grow and exceed certain masses, the disk radii become regulated by magnetic braking and nonideal MHD effects. The synthetic disk radius distribution from this model matches well with the observations. This result suggests that hydrodynamics and nonideal MHD can be dominant in different mass regimes (or evolutionary stages), depending on the rotational energy and protostar+disk mass. This model naturally explains the rarity of large (>100 au) disks and the presence of very small (

Published
2024
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2. Multiple Misaligned Outflows and Warped Accretion Flows in the Proto-multiple System Per-emb-8 and 55

Author

Shang-Jing Lin, Hsi-Wei Yen, and Shih-Ping Lai

Subjects
Protostars, Protoplanetary disks, Young stellar objects, Stellar accretion disks, Star formation, Circumstellar disks, Astronomy, QB1-991
Abstract

To investigate the formation process of multiple systems, we have analyzed the Atacama Large Millimeter/submillimeter Array archival data of the 1.3 mm continuum, ^12 CO (2-1) and C ^18 O (2-1) emission in a proto-multiple system consisting of a Class 0 protostar Per-emb-8 and a Class I protobinary Per-emb-55 A and B . The 1.3 mm continuum emission is likely to primarily trace their protostellar disks, and the Keplerian disk rotation is observed in Per-emb-8 and Per-emb-55 A in the emission lines. In Per-emb-8, we identify two arm-like structures with a length of ∼1000 au connecting the eastern and western of its disk in the continuum and C ^18 O emission. Our analysis suggests that these arm-like structures are most likely infalling flows. In the ^12 CO emission, we discover a second bipolar outflow associated with Per-emb-8. The two bipolar outflows in Per-emb-8 are possibly launched along the normal axes of the misaligned inner and outer parts of its warped protostellar disk. In Per-emb-55, we find that the red- and blueshifted lobes of its bipolar outflow are misaligned by 90°. The presence of the warped disk, multiple misaligned outflows, and asymmetric infalling flows suggest complex dynamics in proto-multiple systems, and these could be related to the tidal interactions between the companions and/or the turbulent environments forming this proto-multiple system.

Published
2024
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3. Early Planet Formation in Embedded Disks (eDisk). XV. Influence of Magnetic Field Morphology in Dense Cores on Sizes of Protostellar Disks

Author

Hsi-Wei Yen, Jonathan P. Williams, Jinshi Sai, Patrick M. Koch, Ilseung Han, Jes K. Jørgensen, Woojin Kwon, Chang Won Lee, Zhi-Yun Li, Leslie W. Looney, Mayank Narang, Nagayoshi Ohashi, Shigehisa Takakuwa, John J. Tobin, Itziar de Gregorio-Monsalvo, Shih-Ping Lai, Jeong-Eun Lee, and Kengo Tomida

Subjects
Star formation, Interstellar magnetic fields, Star forming regions, Protostars, Circumstellar disks, Astrophysics, QB460-466
Abstract

The magnetic field of a molecular cloud core may play a role in the formation of circumstellar disks in the core. We present magnetic field morphologies in protostellar cores of 16 targets in the Atacama Large Millimeter/submillimeter Array large program “Early Planet Formation in Embedded Disks (eDisk),” which resolved their disks with 7 au resolutions. The 0.1 pc scale magnetic field morphologies were inferred from the James Clerk Maxwell Telescope POL-2 observations. The mean orientations and angular dispersions of the magnetic fields in the dense cores are measured and compared with the radii of the 1.3 mm continuum disks and the dynamically determined protostellar masses from the eDisk program. We observe a significant correlation between the disk radii and the stellar masses. We do not find any statistically significant dependence of the disk radii on the projected misalignment angles between the rotational axes of the disks and the magnetic fields in the dense cores, nor on the angular dispersions of the magnetic fields within these cores. However, when considering the projection effect, we cannot rule out a positive correlation between disk radii and misalignment angles in three-dimensional space. Our results suggest that the morphologies of magnetic fields in dense cores do not play a dominant role in the disk formation process. Instead, the sizes of protostellar disks may be more strongly affected by the amount of mass that has been accreted onto star+disk systems, and possibly other parameters, for example, magnetic field strength, core rotation, and magnetic diffusivity.

Published
2024
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4. The First Estimation of the Ambipolar Diffusivity Coefficient from Multi-scale Observations of the Class 0/I Protostar, HOPS-370

Author

Travis J. Thieme, Shih-Ping Lai, Yueh-Ning Lee, Sheng-Jun Lin, and Hsi-Wei Yen

Subjects
Circumstellar disks, Observational astronomy, Radio astronomy, Star formation, Protostars, Young stellar objects, Astrophysics, QB460-466
Abstract

Protostars are born in magnetized environments. As a consequence, the formation of protostellar disks can be suppressed by the magnetic field, efficiently removing the angular momentum of the infalling material. Nonideal MHD effects are proposed as one way to allow protostellar disks to form. Thus, it is important to understand their contributions to observations of protostellar systems. We derive an analytical equation to estimate the ambipolar diffusivity coefficient at the edge of the protostellar disk in the Class 0/I protostar, HOPS-370, for the first time, under the assumption that the disk radius is set by ambipolar diffusion. Using previous results of the protostellar mass, disk mass, disk radius, density and temperature profiles, and magnetic field strength, we estimate the ambipolar diffusivity coefficient to be ${1.7}_{-1.4}^{+1.5}\times {10}^{19}\,{\mathrm{cm}}^{2}\,{{\rm{s}}}^{-1}$ . We quantify the contribution of ambipolar diffusion by estimating its dimensionless Elsässer number to be $\sim {1.7}_{-1.0}^{+1.0}$ , indicating its dynamical importance in this region. We compare our results to those of the chemical calculations of the ambipolar diffusivity coefficient using the Non-Ideal Magnetohydrodynamics Coefficients and Ionization Library, which are consistent with our results. In addition, we compare our derived ambipolar diffusivity coefficient to the diffusivity coefficients for ohmic dissipation and the Hall effect, and find ambipolar diffusion is dominant in our density regime. These results demonstrate a new methodology to understand nonideal MHD effects in observations of protostellar disks. More detailed modeling of the magnetic field, envelope, and microphysics, along with a larger sample of protostellar systems, is needed to further understand the contributions of nonideal MHD.

Published
2024
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5. Multiple Outflows around a Single Protostar IRAS 15398−3359

Author

Jinshi Sai, Hsi-Wei Yen, Masahiro N. Machida, Nagayoshi Ohashi, Yusuke Aso, Anaëlle J. Maury, and Sébastien Maret

Subjects
Protostars, Young stellar objects, Star formation, Stellar winds, Millimeter astronomy, Submillimeter astronomy, Astrophysics, QB460-466
Abstract

We present the results of our mosaic observations of a single Class 0 protostar IRAS 15398−3359 with the Atacama Compact Array in the CO J = 2–1 line. The new observations covering a $\sim 2^{\prime} $ square region reveal elongated redshifted and blueshifted components, which are located at distances of ∼30″–75″ on the northern and southern sides of the protostar, respectively, in addition to the previously observed primary and secondary outflows. These elongated components exhibit Hubble-law-like velocity structures, i.e., an increase of velocity with increasing distance from the protostar, suggesting that they comprise the third outflow associated with the protostar. Besides, a new redshifted component is detected at radii of ∼40″–75″ on the northwestern side of the protostar. This redshifted component also exhibits a Hubble-law-like velocity profile, which could be a counterpart of the secondary outflow mostly detected at blueshifted velocities in a previous study. The three outflows are all misaligned by ∼20°–90°, and the dynamical timescale of the primary outflow is shorter than those of the other outflows, approximately by an order of magnitude. These facts hint that the outflow launch direction has significantly changed with time. The outflow direction may change if the rotational axis and the magnetic field are misaligned or if the dense core is turbulent. We favor the second scenario as the origin of the multiple outflows in IRAS 15398−3359, based on a comparison between the observational results and numerical simulations.

Published
2024
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6. Early Planet Formation in Embedded Disks (eDisk). XIII. Aligned Disks with Nonsettled Dust around the Newly Resolved Class 0 Protobinary R CrA IRAS 32

Author

Frankie J. Encalada, Leslie W. Looney, Shigehisa Takakuwa, John J. Tobin, Nagayoshi Ohashi, Jes K. Jørgensen, Zhi-Yun Li, Yuri Aikawa, Yusuke Aso, Patrick M. Koch, Woojin Kwon, Shih-Ping Lai, Chang Won Lee, Zhe-Yu Daniel Lin, Alejandro Santamaría-Miranda, Itziar de Gregorio-Monsalvo, Nguyen Thi Phuong, Adele Plunkett, Jinshi Sai (Insa Choi), Rajeeb Sharma, Hsi-Wei Yen, and Ilseung Han

Subjects
Protoplanetary disks, Close binary stars, Astrophysics, QB460-466
Abstract

Young protostellar binary systems, with expected ages less than ∼10 ^5 yr, are little modified since birth, providing key clues to binary formation and evolution. We present a first look at the young, Class 0 binary protostellar system R CrA IRAS 32 from the Early Planet Formation in Embedded Disks ALMA large program, which observed the system in the 1.3 mm continuum emission, ^12 CO (2−1), ^13 CO (2−1), C ^18 O (2−1), SO (6 _5 −5 _4 ), and nine other molecular lines that trace disks, envelopes, shocks, and outflows. With a continuum resolution of ∼0.″03 (∼5 au, at a distance of 150 pc), we characterize the newly discovered binary system with a separation of 207 au, their circumstellar disks, and a circumbinary disklike structure. The circumstellar disk radii are 26.9 ± 0.3 and 22.8 ± 0.3 au for sources A and B, respectively, and their circumstellar disk dust masses are estimated as 22.5 ± 1.1 M _⊕ and 12.4 ± 0.6 M _⊕ , respectively. The circumstellar disks and the circumbinary structure have well-aligned position angles and inclinations, indicating formation in a smooth, ordered process such as disk fragmentation. In addition, the circumstellar disks have a near/far-side asymmetry in the continuum emission, suggesting that the dust has yet to settle into a thin layer near the midplane. Spectral analysis of CO isotopologues reveals outflows that originate from both of the sources and possibly from the circumbinary disklike structure. Furthermore, we detect Keplerian rotation in the ^13 CO isotopologues toward both circumstellar disks and likely Keplerian rotation in the circumbinary structure; the latter suggests that it is probably a circumbinary disk.

Published
2024
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7. Early Planet Formation in Embedded Disks (eDisk). XIV. Flared Dust Distribution and Viscous Accretion Heating of the Disk around R CrA IRS 7B-a

Author

Shigehisa Takakuwa, Kazuya Saigo, Miyu Kido, Nagayoshi Ohashi, John J. Tobin, Jes K. Jørgensen, Yuri Aikawa, Yusuke Aso, Sacha Gavino, Ilseung Han, Patrick M. Koch, Woojin Kwon, Chang Won Lee, Jeong-Eun Lee, Zhi-Yun Li, Zhe-Yu Daniel Lin, Leslie W. Looney, Shoji Mori, Jinshi Sai (Insa Choi), Rajeeb Sharma, Patrick D. Sheehan, Kengo Tomida, Jonathan P. Williams, Yoshihide Yamato, and Hsi-Wei Yen

Subjects
Interstellar medium, Planet formation, Radiative transfer, Star formation, Astrophysics, QB460-466
Abstract

We performed radiative transfer calculations and observing simulations to reproduce the 1.3 mm dust-continuum and C ^18 O (2–1) images in the Class I protostar R CrA IRS7B-a, observed with the ALMA Large Program “Early Planet Formation in Embedded Disks (eDisk).” We found that a dust disk model passively heated by the central protostar cannot reproduce the observed peak brightness temperature of the 1.3 mm continuum emission (∼195 K), regardless of the assumptions about the dust opacity. Our calculation suggests that viscous accretion heating in the disk is required to reproduce the observed high brightness temperature. The observed intensity profile of the 1.3 mm dust-continuum emission along the disk minor axis is skewed toward the far side of the disk. Our modeling reveals that this asymmetric intensity distribution requires flaring of the dust along the disk vertical direction with the scale height following h / r ∼ r ^0.3 as a function of radius. These results are in sharp contrast to those of Class II disks, which show geometrically flat dust distributions and lower dust temperatures. From our modeling of the C ^18 O (2–1) emission, the outermost radius of the gas disk is estimated to be ∼80 au, which is larger than that of the dust disk (∼62 au), to reproduce the observed distribution of the C ^18 O (2–1) emission in IRS 7B-a. Our modeling unveils a hot and thick dust disk plus a larger gas disk around one of the eDisk targets, which could be applicable to other protostellar sources in contrast to more evolved sources.

Published
2024
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8. Filamentary Network and Magnetic Field Structures Revealed with BISTRO in the High-mass Star-forming Region NGC 2264: Global Properties and Local Magnetogravitational Configurations

Author

Jia-Wei Wang, Patrick M. Koch, Seamus D. Clarke, Gary Fuller, Nicolas Peretto, Ya-Wen Tang, Hsi-Wei Yen, Shih-Ping Lai, Nagayoshi Ohashi, Doris Arzoumanian, Doug Johnstone, Ray Furuya, Shu-ichiro Inutsuka, Chang Won Lee, Derek Ward-Thompson, Valentin J. M. Le Gouellec, Hong-Li Liu, Lapo Fanciullo, Jihye Hwang, Kate Pattle, Frédérick Poidevin, Mehrnoosh Tahani, Takashi Onaka, Mark G. Rawlings, Eun Jung Chung, Junhao Liu, A-Ran Lyo, Felix Priestley, Thiem Hoang, Motohide Tamura, David Berry, Pierre Bastien, Tao-Chung Ching, Simon Coudé, Woojin Kwon, Mike Chen, Chakali Eswaraiah, Archana Soam, Tetsuo Hasegawa, Keping Qiu, Tyler L. Bourke, Do-Young Byun, Zhiwei Chen, Huei-Ru Vivien Chen, Wen Ping Chen, Jungyeon Cho, Minho Choi, Yunhee Choi, Youngwoo Choi, Antonio Chrysostomou, Sophia Dai, James Di Francesco, Pham Ngoc Diep​, Yasuo Doi, Yan Duan, Hao-Yuan Duan, David Eden, Jason Fiege, Laura M. Fissel, Erica Franzmann, Per Friberg, Rachel Friesen, Tim Gledhill, Sarah Graves, Jane Greaves, Matt Griffin, Qilao Gu, Ilseung Han, Saeko Hayashi, Martin Houde, Tsuyoshi Inoue, Kazunari Iwasaki, Il-Gyo Jeong, Vera Könyves, Ji-hyun Kang, Miju Kang, Janik Karoly, Akimasa Kataoka, Koji Kawabata, Zacariyya Khan, Mi-Ryang Kim, Kee-Tae Kim, Kyoung Hee Kim, Shinyoung Kim, Jongsoo Kim, Hyosung Kim, Gwanjeong Kim, Florian Kirchschlager, 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, Dalei Li, Hua-bai Li, Guangxing Li, Di Li, Sheng-Jun Lin, Tie Liu, Sheng-Yuan Liu, Xing Lu, Steve Mairs, Masafumi Matsumura, Brenda Matthews, Gerald Moriarty-Schieven, Tetsuya Nagata, Fumitaka Nakamura, Hiroyuki Nakanishi, Nguyen Bich Ngoc, Geumsook Park, Harriet Parsons, Tae-Soo Pyo, Lei Qian, Ramprasad Rao, Jonathan Rawlings, Brendan Retter, John Richer, Andrew Rigby, Sarah Sadavoy, Hiro Saito, Giorgio Savini, Masumichi Seta, Ekta Sharma, Yoshito Shimajiri, Hiroko Shinnaga, Xindi Tang, Hoang Duc Thuong, Kohji Tomisaka, Le Ngoc Tram, Yusuke Tsukamoto, Serena Viti, Hongchi Wang, Anthony Whitworth, Jintai Wu, Jinjin Xie, Meng-Zhe Yang, 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, and Sven van Loo

Subjects
Collapsing clouds, Interstellar filaments, Molecular clouds, Interstellar magnetic fields, Interstellar medium, Polarimetry, Astrophysics, QB460-466
Abstract

We report 850 μ m continuum polarization observations toward the filamentary high-mass star-forming region NGC 2264, taken as part of the B -fields In STar forming Regions Observations large program on the James Clerk Maxwell Telescope. These data reveal a well-structured nonuniform magnetic field in the NGC 2264C and 2264D regions with a prevailing orientation around 30° from north to east. Field strength estimates and a virial analysis of the major clumps indicate that NGC 2264C is globally dominated by gravity, while in 2264D, magnetic, gravitational, and kinetic energies are roughly balanced. We present an analysis scheme that utilizes the locally resolved magnetic field structures, together with the locally measured gravitational vector field and the extracted filamentary network. From this, we infer statistical trends showing that this network consists of two main groups of filaments oriented approximately perpendicular to one another. Additionally, gravity shows one dominating converging direction that is roughly perpendicular to one of the filament orientations, which is suggestive of mass accretion along this direction. Beyond these statistical trends, we identify two types of filaments. The type I filament is perpendicular to the magnetic field with local gravity transitioning from parallel to perpendicular to the magnetic field from the outside to the filament ridge. The type II filament is parallel to the magnetic field and local gravity. We interpret these two types of filaments as originating from the competition between radial collapsing, driven by filament self-gravity, and longitudinal collapsing, driven by the region's global gravity.

Published
2024
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9. Polarization in the GG Tau Ring—Confronting Dust Self-scattering, Dust Mechanical and Magnetic Alignment, Spirals, and Dust Grain Drift

Author

Ya-Wen Tang, Anne Dutrey, Patrick M. Koch, Stephane Guilloteau, Hsi-Wei Yen, Emmanuel di Folco, Eric Pantin, Takayuki Muto, Akimasa Kataoka, and Robert Brauer

Subjects
Interstellar medium, Circumstellar disks, Astrophysics, QB460-466
Abstract

We report Atacama Large Millimeter/submillimeter Array (ALMA) polarization observations at 3 and 0.9 mm toward the GG Tau A system. In the ring, the percentage is relatively homogeneous at 3 mm, being 1.2%, while it exhibits a clear radial variation at 0.9 mm with a mean increasing from 0.6% to 2.8% toward larger radius ( r ). The polarization orientation at r > 1.″85 appears nearly azimuthal at both wavelengths. At r < 1.″85, the pattern remains azimuthal at 3 mm but becomes radial at 0.9 mm. The dust self-scattering model with ${a}_{\max }$ of 1 mm could reproduce the observed polarization orientation and percentage at 0.9 mm, but the expected polarization percentage at 3 mm would be 0.2%, much smaller than the detected 1.2%. Dust alignment with poloidal magnetic field could qualitatively reproduce the flip in polarization at r < 1.″85 and also the detected polarization percentage. A closer inspection of the nearly azimuthal pattern reveals that polarization orientations are systematically deviating by −9.°0 ± 1.°2 from the tangent of the orbit ellipses. This deviation agrees with the direction of the spiral pattern observed in the near-infrared, but it is unclear how dust grains could be aligned along such spirals. For the scenario where the −9° deviation (−7.°3 after considering the inclination effect) measures the radial component of the dust drift motion, the expected inward drifting velocity would be ∼12.8% of the Keplerian speed, a factor of 2.8 larger than the theoretical predictions. Possible additional interpretations of the polarization are discussed, but there is no single mechanism that could explain the detected polarization simultaneously.

Published
2023
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10. Early Planet Formation in Embedded Disks (eDisk). XII. Accretion Streamers, Protoplanetary Disk, and Outflow in the Class I Source Oph IRS 63

Author

Christian Flores, Nagayoshi Ohashi, John J. Tobin, Jes K. Jørgensen, Shigehisa Takakuwa, Zhi-Yun Li, Zhe-Yu Daniel Lin, Merel L. R. van ’t Hoff, Adele L. Plunkett, Yoshihide Yamato, Jinshi Sai (Insa Choi), Patrick M. Koch, Hsi-Wei Yen, Yuri Aikawa, Yusuke Aso, Itziar de Gregorio-Monsalvo, Miyu Kido, Woojin Kwon, Jeong-Eun Lee, Chang Won Lee, Leslie W. Looney, Alejandro Santamaría-Miranda, Rajeeb Sharma, Travis J. Thieme, Jonathan P. Williams, Ilseung Han, Suchitra Narayanan, and Shih-Ping Lai

Subjects
Protoplanetary disks, Protostars, Stellar accretion, Low mass stars, Star formation, Planet formation, Astrophysics, QB460-466
Abstract

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the Class I source Oph IRS 63 in the context of the Early Planet Formation in Embedded Disks large program. Our ALMA observations of Oph IRS 63 show a myriad of protostellar features, such as a shell-like bipolar outflow (in ^12 CO), an extended rotating envelope structure (in ^13 CO), a streamer connecting the envelope to the disk (in C ^18 O), and several small-scale spiral structures seen toward the edge of the dust continuum (in SO). By analyzing the velocity pattern of ^13 CO and C ^18 O, we measure a protostellar mass of M _⋆ = 0.5 ± 0.2 M _⊙ and confirm the presence of a disk rotating at almost Keplerian velocity that extends up to ∼260 au. These calculations also show that the gaseous disk is about four times larger than the dust disk, which could indicate dust evolution and radial drift. Furthermore, we model the C ^18 O streamer and SO spiral structures as features originating from an infalling rotating structure that continuously feeds the young protostellar disk. We compute an envelope-to-disk mass infall rate of ∼10 ^−6 M _⊙ yr ^−1 and compare it to the disk-to-star mass accretion rate of ∼10 ^−8 M _⊙ yr ^−1 , from which we infer that the protostellar disk is in a mass buildup phase. At the current mass infall rate, we speculate that soon the disk will become too massive to be gravitationally stable.

Published
2023
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11. Early Planet Formation in Embedded Disks (eDisk). VIII. A Small Protostellar Disk around the Extremely Low Mass and Young Class 0 Protostar IRAS 15398–3359

Author

Travis J. Thieme, Shih-Ping Lai, Nagayoshi Ohashi, John J. Tobin, Jes K. Jørgensen, Jinshi Sai (Insa Choi), Yusuke Aso, Jonathan P. Williams, Yoshihide Yamato, Yuri Aikawa, Itziar de Gregorio-Monsalvo, Ilseung Han, Woojin Kwon, Chang Won Lee, Jeong-Eun Lee, Zhi-Yun Li, Zhe-Yu Daniel Lin, Leslie W. Looney, Suchitra Narayanan, Nguyen Thi Phuong, Adele L. Plunkett, Alejandro Santamaría-Miranda, Rajeeb Sharma, Shigehisa Takakuwa, and Hsi-Wei Yen

Subjects
Circumstellar disks, Observational astronomy, Protostars, Radio astronomy, Radio interferometry, Star formation, Astrophysics, QB460-466
Abstract

Protostellar disks are an ubiquitous part of the star formation process and the future sites of planet formation. As part of the Early Planet Formation in Embedded Disks large program, we present high angular resolution dust continuum (∼40 mas) and molecular line (∼150 mas) observations of the Class 0 protostar IRAS 15398–3359. The dust continuum is small, compact, and centrally peaked, while more extended dust structures are found in the outflow directions. We perform a 2D Gaussian fitting and find the deconvolved size and 2 σ radius of the dust disk to be 4.5 × 2.8 au and 3.8 au, respectively. We estimate the gas+dust disk mass assuming optically thin continuum emission to be 0.6 M _J –1.8 M _J , indicating a very low mass disk. The CO isotopologues trace components of the outflows and inner envelope, while SO traces a compact, rotating disk-like component. Using several rotation curve fittings on the position–velocity diagram of the SO emission, the lower limits of the protostellar mass and gas disk radius are 0.022 M _⊙ and 31.2 au, respectively, from our Modified 2 single power-law fitting. A conservative upper limit of the protostellar mass is inferred to be 0.1 M _⊙ . The protostellar mass accretion rate and the specific angular momentum at the protostellar disk edge are found to be in the range of (1.3–6.1) × 10 ^−6 M _⊙ yr ^−1 and (1.2–3.8) × 10 ^−4 km s ^−1 pc, respectively, with an age estimated between 0.4 × 10 ^4 yr and 7.5 × 10 ^4 yr. At this young age with no clear substructures in the disk, planet formation would likely not yet have started. This study highlights the importance of high-resolution observations and systematic fitting procedures when deriving dynamical properties of deeply embedded Class 0 protostars.

Published
2023
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12. Early Planet Formation in Embedded Disks (eDisk). X. Compact Disks, Extended Infall, and a Fossil Outburst in the Class I Oph IRS43 Binary

Author

Suchitra Narayanan, Jonathan P. Williams, John J. Tobin, Jes K. Jørgensen, Nagayoshi Ohashi, Zhe-Yu Daniel Lin, Merel L. R. van’t Hoff, Zhi-Yun Li, Adele L. Plunkett, Leslie W. Looney, Shigehisa Takakuwa, Hsi-Wei Yen, Yusuke Aso, Christian Flores, Jeong-Eun Lee, Shih-Ping Lai, Woojin Kwon, Itziar de Gregorio-Monsalvo, Rajeeb Sharma, and Chang Won Lee

Subjects
Protostars, Astrophysics, QB460-466
Abstract

We present the first results from the Early Planet Formation in Embedded Disks Atacama Large Millimeter/submillimeter Array Large Program toward Oph IRS43, a binary system of solar mass protostars. The 1.3 mm dust continuum observations resolve a compact disk, ∼6 au radius, around the northern component and show that the disk around the southern component is even smaller, ≲3 au. CO, ^13 CO, and C ^18 O maps reveal a large cavity in a low-mass envelope that shows kinematic signatures of rotation and infall extending out to ∼2000 au. An expanding CO bubble centered on the extrapolated location of the source ∼130 yr ago suggests a recent outburst. Despite the small size of the disks, the overall picture is of a remarkably large and dynamically active region.

Published
2023
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13. Early Planet Formation in Embedded Disks (eDisk). VI. Kinematic Structures around the Very-low-mass Protostar IRAS 16253-2429

Author

Yusuke Aso, Woojin Kwon, Nagayoshi Ohashi, Jes K. Jørgensen, John J. Tobin, Yuri Aikawa, Itziar de Gregorio-Monsalvo, Ilseung Han, Miyu Kido, Patrick M. Koch, Shih-Ping Lai, Chang Won Lee, Jeong-Eun Lee, Zhi-Yun Li, Zhe-Yu Daniel Lin, Leslie W. Looney, Suchitra Narayanan, Nguyen Thi Phuong, Jinshi Sai (Insa Choi), Kazuya Saigo, Alejandro Santamaría-Miranda, Rajeeb Sharma, Shigehisa Takakuwa, Travis J. Thieme, Kengo Tomida, Jonathan P. Williams, and Hsi-Wei Yen

Subjects
Circumstellar disks, Protostars, Low mass stars, Astrophysics, QB460-466
Abstract

Precise estimates of protostellar masses are crucial to characterize the formation of stars of low masses down to brown dwarfs (BDs; M _* < 0.08 M _☉ ). The most accurate estimation of protostellar mass uses the Keplerian rotation in the circumstellar disk around the protostar. To apply the Keplerian rotation method to a protostar at the low-mass end, we have observed the Class 0 protostar IRAS 16253-2429 using the Atacama Large Millimeter/submillimeter Array (ALMA) in the 1.3 mm continuum at an angular resolution of 0.″07 (10 au), and in the ^12 CO, C ^18 O, ^13 CO ( J = 2–1), and SO ( J _N = 6 _5 −5 _4 ) molecular lines, as part of the ALMA Large Program Early Planet Formation in Embedded Disks project. The continuum emission traces a nonaxisymmetric, disk-like structure perpendicular to the associated ^12 CO outflow. The position–velocity (PV) diagrams in the C ^18 O and ^13 CO lines can be interpreted as infalling and rotating motions. In contrast, the PV diagram along the major axis of the disk-like structure in the ^12 CO line allows us to identify Keplerian rotation. The central stellar mass and the disk radius are estimated to be ∼0.12–0.17 M _☉ and ∼13–19 au, respectively. The SO line suggests the existence of an accretion shock at a ring ( r ∼ 28 au) surrounding the disk and a streamer from the eastern side of the envelope. IRAS 16253-2429 is not a proto-BD but has a central stellar mass close to the BD mass regime, and our results provide a typical picture of such very-low-mass protostars.

Published
2023
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14. Early Planet Formation in Embedded Disks (eDisk). IX. High-resolution ALMA Observations of the Class 0 Protostar R CrA IRS5N and Its Surroundings

Author

Rajeeb Sharma, Jes K. Jørgensen, Sacha Gavino, Nagayoshi Ohashi, John J. Tobin, Zhe-Yu Daniel Lin, Zhi-Yun Li, Shigehisa Takakuwa, Chang Won Lee, Jinshi Sai (Insa Choi), Woojin Kwon, Itziar de Gregorio-Monsalvo, Alejandro Santamaría-Miranda, Hsi-Wei Yen, Yuri Aikawa, Yusuke Aso, Shih-Ping Lai, Jeong-Eun Lee, Leslie W. Looney, Nguyen Thi Phuong, Travis J. Thieme, and Jonathan P. Williams

Subjects
Protostars, Young stellar objects, Protoplanetary disks, Interstellar medium, Astrophysics, QB460-466
Abstract

We present high-resolution high-sensitivity observations of the Class 0 protostar RCrA IRS5N as part of the Atacama Large Milimeter/submilimeter Array large program Early Planet Formation in Embedded Disks. The 1.3 mm continuum emission reveals a flattened continuum structure around IRS5N, consistent with a protostellar disk in the early phases of evolution. The continuum emission appears smooth and shows no substructures. However, a brightness asymmetry is observed along the minor axis of the disk, suggesting that the disk is optically and geometrically thick. We estimate the disk mass to be between 0.007 and 0.02 M _⊙ . Furthermore, molecular emission has been detected from various species, including C ^18 O (2–1), ^12 CO (2–1), ^13 CO (2–1), and H _2 CO (3 _0,3 − 2 _0,2 , 3 _2,1 − 2 _2,0 , and 3 _2,2 − 2 _2,1 ). By conducting a position–velocity analysis of the C ^18 O (2–1) emission, we find that the disk of IRS5N exhibits characteristics consistent with Keplerian rotation around a central protostar with a mass of approximately 0.3 M _⊙ . Additionally, we observe dust continuum emission from the nearby binary source IRS5a/b. The emission in ^12 CO toward IRS5a/b seems to emanate from IRS5b and flow into IRS5a, suggesting material transport between their mutual orbits. The lack of a detected outflow and large-scale negatives in ^12 CO observed toward IRS5N suggests that much of the flux from IRS5N is being resolved out. Using a 1D radiative transfer model, we infer the mass of the envelope surrounding IRS5N to be ∼1.2 M _⊙ . Due to this substantial surrounding envelope, the central IRS5N protostar is expected to be significantly more massive in the future.

Published
2023
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15. Early Planet Formation in Embedded Disks (eDisk). V. Possible Annular Substructure in a Circumstellar Disk in the Ced110 IRS4 System

Author

Jinshi Sai (Insa Choi), Hsi-Wei Yen, Nagayoshi Ohashi, John J. Tobin, Jes K. Jørgensen, Shigehisa Takakuwa, Kazuya Saigo, Yusuke Aso, Zhe-Yu Daniel Lin, Patrick M. Koch, Yuri Aikawa, Christian Flores, Itziar de Gregorio-Monsalvo, Ilseung Han, Miyu Kido, Woojin Kwon, Shih-Ping Lai, Chang Won Lee, Jeong-Eun Lee, Zhi-Yun Li, Leslie W. Looney, Shoji Mori, Nguyen Thi Phuong, Alejandro Santamaría-Miranda, Rajeeb Sharma, Travis J. Thieme, Kengo Tomida, and Jonathan P. Williams

Subjects
Planet formation, Star formation, Low mass stars, Protoplanetary disks, Protostars, Young stellar objects, Astrophysics, QB460-466
Abstract

We have observed the Class 0/I protostellar system Ced110 IRS4 at an angular resolution of 0.″05 (∼10 au) as part of the Atacama Large Millimeter/submillimeter Array large program, Early Planet Formation in Embedded Disks. The 1.3 mm dust continuum emission reveals that Ced110 IRS4 is a binary system with a projected separation of ∼250 au. The continuum emissions associated with the main source and its companion, named Ced110 IRS4A and IRS4B, respectively, exhibit disk-like shapes and likely arise from dust disks around the protostars. The continuum emission of Ced110 IRS4A has a radius of ∼91.7 au (∼0.″485) and shows bumps along its major axis with an asymmetry. The bumps can be interpreted as a shallow, ring-like structure at a radius of ∼40 au (∼0.″2) in the continuum emission, as demonstrated from two-dimensional intensity distribution models. A rotation curve analysis on the C ^18 O and ^13 CO J = 2–1 lines reveals the presence of a Keplerian disk within a radius of 120 au around Ced110 IRS4A, which supports the interpretation that the dust continuum emission arises from a disk. The ring-like structure in the dust continuum emission might indicate a possible annular substructure in the surface density of the embedded disk, although the possibility that it is an apparent structure due to the optically thick continuum emission cannot be ruled out.

Published
2023
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16. Early Planet Formation in Embedded Disks (eDisk). VII. Keplerian Disk, Disk Substructure, and Accretion Streamers in the Class 0 Protostar IRAS 16544–1604 in CB 68

Author

Miyu Kido, Shigehisa Takakuwa, Kazuya Saigo, Nagayoshi Ohashi, John J. Tobin, Jes K. Jørgensen, Yuri Aikawa, Yusuke Aso, Frankie J. Encalada, Christian Flores, Sacha Gavino, Itziar de Gregorio-Monsalvo, Ilseung Han, Shingo Hirano, Patrick M. Koch, Woojin Kwon, Shih-Ping Lai, Chang Won Lee, Jeong-Eun Lee, Zhi-Yun Li, Zhe-Yu Daniel Lin, Leslie W. Looney, Shoji Mori, Suchitra Narayanan, Adele L. Plunkett, Nguyen Thi Phuong, Jinshi Sai (Insa Choi), Alejandro Santamaría-Miranda, Rajeeb Sharma, Patrick D. Sheehan, Travis J. Thieme, Kengo Tomida, Merel L. R. van ’t Hoff, Jonathan P. Williams, Yoshihide Yamato, and Hsi-Wei Yen

Subjects
Star formation, Interstellar medium, Planet formation, Astrophysics, QB460-466
Abstract

We present observations of the Class 0 protostar IRAS 16544–1604 in CB 68 from the “Early Planet Formation in Embedded Disks (eDisk)” ALMA Large program. The ALMA observations target continuum and lines at 1.3 mm with an angular resolution of ∼5 au. The continuum image reveals a dusty protostellar disk with a radius of ∼30 au seen close to edge-on and asymmetric structures along both the major and minor axes. While the asymmetry along the minor axis can be interpreted as the effect of the dust flaring, the asymmetry along the major axis comes from a real nonaxisymmetric structure. The C ^18 O image cubes clearly show the gas in the disk that follows a Keplerian rotation pattern around a ∼0.14 M _⊙ central protostar. Furthermore, there are ∼1500 au scale streamer-like features of gas connecting from northeast, north–northwest, and northwest to the disk, as well as the bending outflow as seen in the ^12 CO (2–1) emission. At the apparent landing point of the NE streamer, there is SO (6 _5 –5 _4 ) and SiO (5–4) emission detected. The spatial and velocity structure of the NE streamer can be interpreted as a free-falling gas with a conserved specific angular momentum, and the detection of the SO and SiO emission at the tip of the streamer implies the presence of accretion shocks. Our eDisk observations have unveiled that the Class 0 protostar in CB 68 has a Keplerian-rotating disk with a flaring and nonaxisymmetric structure associated with accretion streamers and outflows.

Published
2023
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17. The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43

Author

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

Subjects
Stellar-interstellar interactions, Interstellar magnetic fields, Young stellar objects, Dust continuum emission, Starlight polarization, Molecular clouds, Astrophysics, QB460-466
Abstract

We present observations of polarized dust emission at 850 μ m from the L43 molecular cloud, which sits in the Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope as a part of the BISTRO large program. L43 is a dense ( ${N}_{{{\rm{H}}}_{2}}\sim {10}^{22}$ –10 ^23 cm ^−2 ) complex molecular cloud with a submillimeter-bright starless core and two protostellar sources. There appears to be an evolutionary gradient along the isolated filament that L43 is embedded within, with the most evolved source closest to the Sco OB2 association. One of the protostars drives a CO outflow that has created a cavity to the southeast. We see a magnetic field that appears to be aligned with the cavity walls of the outflow, suggesting interaction with the outflow. We also find a magnetic field strength of up to ∼160 ± 30 μ G in the main starless core and up to ∼90 ± 40 μ G in the more diffuse, extended region. These field strengths give magnetically super- and subcritical values, respectively, and both are found to be roughly trans-Alfvénic. We also present a new method of data reduction for these denser but fainter objects like starless cores.

Published
2023
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18. Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS

Author

Yoshihide Yamato, Yuri Aikawa, Nagayoshi Ohashi, John J. Tobin, Jes K. Jørgensen, Shigehisa Takakuwa, Yusuke Aso, Jinshi Sai (Insa Choi), Christian Flores, Itziar de Gregorio-Monsalvo, Shingo Hirano, Ilseung Han, Miyu Kido, Patrick M. Koch, Woojin Kwon, Shih-Ping Lai, Chang Won Lee, Jeong-Eun Lee, Zhi-Yun Li, Zhe-Yu Daniel Lin, Leslie W. Looney, Shoji Mori, Suchitra Narayanan, Nguyen Thi Phuong, Kazuya Saigo, Alejandro Santamaría-Miranda, Rajeeb Sharma, Travis J. Thieme, Kengo Tomida, Merel L. R. van ’t Hoff, and Hsi-Wei Yen

Subjects
Protoplanetary disks, Protostars, Planetary system formation, Astrophysics, QB460-466
Abstract

Constraining the physical and chemical structure of young embedded disks is crucial for understanding the earliest stages of planet formation. As part of the Early Planet Formation in Embedded Disks Atacama Large Millimeter/submillimeter Array Large Program, we present high spatial resolution (∼0.″1 or ∼15 au) observations of the 1.3 mm continuum and ^13 CO J = 2–1, C ^18 O J = 2–1, and SO J _N = 6 _5 –5 _4 molecular lines toward the disk around the Class I protostar L1489 IRS. The continuum emission shows a ring-like structure at 56 au from the central protostar and tenuous, optically thin emission extending beyond ∼300 au. The ^13 CO emission traces the warm disk surface, while the C ^18 O emission originates from near the disk midplane. The coincidence of the radial emission peak of C ^18 O with the dust ring may indicate a gap-ring structure in the gaseous disk as well. The SO emission shows a highly complex distribution, including a compact, prominent component at ≲30 au, which is likely to originate from thermally sublimated SO molecules. The compact SO emission also shows a velocity gradient along a direction tilted slightly (∼15°) with respect to the major axis of the dust disk, which we interpret as an inner warped disk in addition to the warp around ∼200 au suggested by previous work. These warped structures may be formed by a planet or companion with an inclined orbit, or by a gradual change in the angular momentum axis during gas infall.

Published
2023
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19. Early Planet Formation in Embedded Disks (eDisk). I. Overview of the Program and First Results

Author

Nagayoshi Ohashi, John J. Tobin, Jes K. Jørgensen, Shigehisa Takakuwa, Patrick Sheehan, Yuri Aikawa, Zhi-Yun Li, Leslie W. Looney, Jonathan P. Williams, Yusuke Aso, Rajeeb Sharma, Jinshi Sai (Insa Choi), Yoshihide Yamato, Jeong-Eun Lee, Kengo Tomida, Hsi-Wei Yen, Frankie J. Encalada, Christian Flores, Sacha Gavino, Miyu Kido, Ilseung Han, Zhe-Yu Daniel Lin, Suchitra Narayanan, Nguyen Thi Phuong, Alejandro Santamaría-Miranda, Travis J. Thieme, Merel L. R. van ’t Hoff, Itziar de Gregorio-Monsalvo, Patrick M. Koch, Woojin Kwon, Shih-Ping Lai, Chang Won Lee, Adele Plunkett, Kazuya Saigo, Shingo Hirano, Ka Ho Lam, and Shoji Mori

Subjects
Protoplanetary disks, Planetary system formation, Protostars, Submillimeter astronomy, Astrophysics, QB460-466
Abstract

We present an overview of the Large Program, “Early Planet Formation in Embedded Disks (eDisk),” conducted with the Atacama Large Millimeter/submillimeter Array (ALMA). The ubiquitous detections of substructures, particularly rings and gaps, in protoplanetary disks around T Tauri stars raise the possibility that at least some planet formation may have already started during the embedded stages of star formation. In order to address exactly how and when planet formation is initiated, the program focuses on searching for substructures in disks around 12 Class 0 and 7 Class I protostars in nearby (

Published
2023
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20. Early Planet Formation in Embedded Disks (eDisk). III. A First High-resolution View of Submillimeter Continuum and Molecular Line Emission toward the Class 0 Protostar L1527 IRS

Author

Merel L. R. van ’t Hoff, John J. Tobin, Zhi-Yun Li, Nagayoshi Ohashi, Jes K. Jørgensen, Zhe-Yu Daniel Lin, Yuri Aikawa, Yusuke Aso, Itziar de Gregorio-Monsalvo, Sacha Gavino, Ilseung Han, Patrick M. Koch, Woojin Kwon, Chang Won Lee, Jeong-Eun Lee, Leslie W. Looney, Suchitra Narayanan, Adele Plunkett, Jinshi Sai (Insa Choi), Alejandro Santamaría-Miranda, Rajeeb Sharma, Patrick D. Sheehan, Shigehisa Takakuwa, Travis J. Thieme, Jonathan P. Williams, Shih-Ping Lai, Nguyen Thi Phuong, and Hsi-Wei Yen

Subjects
Interstellar molecules, Protostars, Astrophysics, QB460-466
Abstract

Studying the physical and chemical conditions of young embedded disks is crucial to constrain the initial conditions for planet formation. Here we present Atacama Large Millimeter/submillimeter Array observations of dust continuum at ∼0.″06 (8 au) resolution and molecular line emission at ∼0.″17 (24 au) resolution toward the Class 0 protostar L1527 IRS from the Large Program eDisk (Early Planet Formation in Embedded Disks). The continuum emission is smooth without substructures but asymmetric along both the major and minor axes of the disk as previously observed. The detected lines of ^12 CO, ^13 CO, C ^18 O, H _2 CO, c-C _3 H _2 , SO, SiO, and DCN trace different components of the protostellar system, with a disk wind potentially visible in ^12 CO. The ^13 CO brightness temperature and the H _2 CO line ratio confirm that the disk is too warm for CO freezeout, with the snowline located at ∼350 au in the envelope. Both molecules show potential evidence of a temperature increase around the disk–envelope interface. SO seems to originate predominantly in UV-irradiated regions such as the disk surface and the outflow cavity walls rather than at the disk–envelope interface as previously suggested. Finally, the continuum asymmetry along the minor axis is consistent with the inclination derived from the large-scale (100″ or 14,000 au) outflow, but opposite to that based on the molecular jet and envelope emission, suggesting a misalignment in the system. Overall, these results highlight the importance of observing multiple molecular species in multiple transitions to characterize the physical and chemical environment of young disks.

Published
2023
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21. Early Planet Formation in Embedded Disks (eDisk). II. Limited Dust Settling and Prominent Snow Surfaces in the Edge-on Class I Disk IRAS 04302+2247

Author

Zhe-Yu Daniel Lin, Zhi-Yun Li, John J. Tobin, Nagayoshi Ohashi, Jes Kristian Jørgensen, Leslie W. Looney, Yusuke Aso, Shigehisa Takakuwa, Yuri Aikawa, Merel L. R. van’t Hoff, Itziar de Gregorio-Monsalvo, Frankie J. Encalada, Christian Flores, Sacha Gavino, Ilseung Han, Miyu Kido, Patrick M. Koch, Woojin Kwon, Shih-Ping Lai, Chang Won Lee, Jeong-Eun Lee, Nguyen Thi Phuong, Jinshi Sai (Insa Choi), Rajeeb Sharma, Patrick Sheehan, Travis J. Thieme, Jonathan P. Williams, Yoshihide Yamato, and Hsi-Wei Yen

Subjects
Protoplanetary disks, Circumstellar disks, Interstellar medium, Protostars, Submillimeter astronomy, Astrophysics, QB460-466
Abstract

While dust disks around optically visible, Class II protostars are found to be vertically thin, when and how dust settles to the midplane are unclear. As part of the Atacama Large Millimeter/submillimeter Array large program, Early Planet Formation in Embedded Disks, we analyze the edge-on, embedded, Class I protostar IRAS 04302+2247, also nicknamed the “Butterfly Star.” With a resolution of 0.″05 (8 au), the 1.3 mm continuum shows an asymmetry along the minor axis that is evidence of an optically thick and geometrically thick disk viewed nearly edge-on. There is no evidence of rings and gaps, which could be due to the lack of radial substructure or the highly inclined and optically thick view. With 0.″1 (16 au) resolution, we resolve the 2D snow surfaces, i.e., the boundary region between freeze-out and sublimation, for ^12 CO J = 2–1, ^13 CO J = 2–1, C ^18 O J = 2–1, H _2 CO J = 3 _0,3 –2 _0,2 , and SO J = 6 _5 –5 _4 , and constrain the CO midplane snow line to ∼130 au. We find Keplerian rotation around a protostar of 1.6 ± 0.4 M _⊙ using C ^18 O. Through forward ray-tracing using RADMC-3D, we find that the dust scale height is ∼6 au at a radius of 100 au from the central star and is comparable to the gas pressure scale height. The results suggest that the dust of this Class I source has yet to vertically settle significantly.

Published
2023
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22. The HH 24 Complex: Jets, Multiple Star Formation, and Orphaned Protostars

Author

Bo Reipurth, J. Bally, Hsi-Wei Yen, H. G. Arce, L.-F. Rodríguez, A. C. Raga, T. R. Geballe, R. Rao, F. Comerón, S. Mikkola, C. A. Aspin, and J. Walawender

Subjects
Herbig-Haro objects, Multiple stars, Young stellar objects, Circumstellar disks, Protostars, Herbig Ae/Be stars, Astronomy, QB1-991
Abstract

The HH 24 complex harbors five collimated jets emanating from a small protostellar multiple system. We have carried out a multiwavelength study of the jets, their driving sources, and the cloud core hosting the embedded stellar system, based on data from the Hubble Space Telescope, Gemini, Subaru, Apache Point Observatory 3.5 m, Karl G. Jansky Very Large Array, and Atacama Large Millimeter/submillimeter Array (ALMA) telescopes. The data show that the multiple system, SSV 63, contains at least 7 sources, ranging in mass from the hydrogen-burning limit to proto-Herbig Ae stars. The stars are in an unstable nonhierarchical configuration, and one member, a borderline brown dwarf, is moving away from the protostellar system with 25 km s ^−1 , after being ejected ∼5800 yr ago as an orphaned protostar. Five of the embedded sources are surrounded by small, possibly truncated, disks resolved at 1.3 mm with ALMA. Proper motions and radial velocities imply jet speeds of 200–300 km s ^−1 . The two main HH 24 jets, E and C, form a bipolar jet system that traces the innermost portions of parsec-scale chains of Herbig–Haro and H _2 shocks with a total extent of at least 3 pc. H _2 CO and C ^18 O observations show that the core has been churned and continuously fed by an infalling streamer. ^13 CO and ^12 CO trace compact, low-velocity, cavity walls carved by the jets and an ultracompact molecular outflow from the most embedded object. Chaotic N -body dynamics likely will eject several more of these objects. The ejection of stars from their feeding zones sets their masses. Dynamical decay of nonhierarchical systems can thus be a major contributor to establishing the initial mass function.

Published
2023
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23. Increasing Mass-to-flux Ratio from the Dense Core to the Protostellar Envelope around the Class 0 Protostar HH 211

Author

Hsi-Wei Yen, Patrick M. Koch, Chin-Fei Lee, Naomi Hirano, Nagayoshi Ohashi, Jinshi Sai (Insa Choi), Shigehisa Takakuwa, Ya-Wen Tang, Ken’ichi Tatematsu, and Bo Zhao

Subjects
Star formation, Interstellar magnetic fields, Star forming regions, Protostars, Circumstellar disks, Astrophysics, QB460-466
Abstract

To study the transportation of magnetic flux from large to small scales in protostellar sources, we analyzed the Nobeyama 45 m N _2 H ^+ (1–0), JCMT 850 μ m polarization, and Atacama Large Millimeter/submillimeter Array (ALMA) C ^18 O (2–1) and 1.3 and 0.8 mm (polarized) continuum data of the Class 0 protostar HH 211. The magnetic field strength in the dense core on a 0.1 pc scale was estimated with the single-dish line and polarization data using the Davis–Chandrasekhar–Fermi method, and that in the protostellar envelope on a 600 au scale was estimated from the force balance between the gravity and magnetic field tension by analyzing the gas kinematics and magnetic field structures with the ALMA data. Our analysis suggests that from 0.1 pc–600 au scales, the magnetic field strength increases from 40–107 μ G to 0.3–1.2 mG with a scaling relation between the magnetic field strength and density of B ∝ ρ ^0.36±0.08 , and the mass-to-flux ratio increases from 1.2–3.7 to 9.1–32.3. The increase in the mass-to-flux ratio could suggest that the magnetic field is partially decoupled from the neutral matter between 0.1 pc and 600 au scales, and hint at efficient ambipolar diffusion in the infalling protostellar envelope in HH 211, which is the dominant nonideal magnetohydrodynamic effect considering the density on these scales. Thus, our results could support the scenario of efficient ambipolar diffusion enabling the formation of the 20 au Keplerian disk in HH 211.

Published
2023
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24. JCMT BISTRO Observations: Magnetic Field Morphology of Bubbles Associated with NGC 6334

Author

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

Subjects
H II regions, Interstellar magnetic fields, Star formation, Molecular clouds, Dust continuum emission, Astrophysics, QB460-466
Abstract

We study the H ii regions associated with the NGC 6334 molecular cloud observed in the submillimeter and taken as part of the B -fields In STar-forming Region Observations Survey. In particular, we investigate the polarization patterns and magnetic field morphologies associated with these H ii regions. Through polarization pattern and pressure calculation analyses, several of these bubbles indicate that the gas and magnetic field lines have been pushed away from the bubble, toward an almost tangential (to the bubble) magnetic field morphology. In the densest part of NGC 6334, where the magnetic field morphology is similar to an hourglass, the polarization observations do not exhibit observable impact from H ii regions. We detect two nested radial polarization patterns in a bubble to the south of NGC 6334 that correspond to the previously observed bipolar structure in this bubble. Finally, using the results of this study, we present steps (incorporating computer vision; circular Hough transform) that can be used in future studies to identify bubbles that have physically impacted magnetic field lines.

Published
2023
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25. Probing Velocity Structures of Protostellar Envelopes: Infalling and Rotating Envelopes within Turbulent Dense Cores

Author

Jinshi Sai (Insa Choi), Nagayoshi Ohashi, Hsi-Wei Yen, Anaëlle J. Maury, and Sébastien Maret

Subjects
Star formation, Low mass stars, Interstellar medium, Protostars, Young stellar objects, Radio astronomy, Astrophysics, QB460-466
Abstract

We have observed the three low-mass protostars, IRAS 15398−3359, L1527 IRS, and TMC-1A, with the ALMA 12 m array, the ACA 7 m array, and the IRAM-30 m and APEX telescopes in the C ^18 O J = 2–1 emission. Overall, the C ^18 O emission shows clear velocity gradients at radii of ∼100–1000 au, which likely originate from the rotation of envelopes, while velocity gradients are less clear and velocity structures are more perturbed on scales of ∼1000–10,000 au. IRAS 15398−3359 and L1527 IRS show a break at radii of ∼1200 and ∼1700 au in the radial profile of the peak velocity, respectively. The peak velocity is proportional to r ^−1.38 or r ^−1.7 within the break radius, which can be interpreted as indicating the rotational motion of the envelope with a degree of contamination by gas motions on larger spatial scales. The peak velocity follows v _peak ∝ r ^0.68 or v _peak ∝ r ^0.46 outside the break radius, which is similar to the J / M – R relation of dense cores. TMC-1A exhibits a radial profile of the peak velocity that is not consistent with the rotational motion of the envelope nor the J / M – R relation. The origin of the relation of v _peak ∝ r ^0.46 – r ^0.68 is investigated by examining correlations of the velocity deviation ( δ v ) and the spatial scale ( τ ) in the two sources. The obtained spatial correlations, δ v ∝ τ ^∼0.6 , are consistent with the scaling law predicted by turbulence models, which may suggest that large-scale velocity structures originate from turbulence.

Published
2023
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26. First BISTRO Observations of the Dark Cloud Taurus L1495A-B10: The Role of the Magnetic Field in the Earliest Stages of Low-mass Star Formation

Author

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

Subjects
Interstellar magnetic fields, Molecular clouds, Starlight polarization, Collapsing clouds, Interstellar filaments, Astrophysics, QB460-466
Abstract

We present BISTRO Survey 850 μ m dust emission polarization observations of the L1495A-B10 region of the Taurus molecular cloud, taken at the James Clerk Maxwell Telescope (JCMT). We observe a roughly triangular network of dense filaments. We detect nine of the dense starless cores embedded within these filaments in polarization, finding that the plane-of-sky orientation of the core-scale magnetic field lies roughly perpendicular to the filaments in almost all cases. We also find that the large-scale magnetic field orientation measured by Planck is not correlated with any of the core or filament structures, except in the case of the lowest-density core. We propose a scenario for early prestellar evolution that is both an extension to, and consistent with, previous models, introducing an additional evolutionary transitional stage between field-dominated and matter-dominated evolution, observed here for the first time. In this scenario, the cloud collapses first to a sheet-like structure. Uniquely, we appear to be seeing this sheet almost face on. The sheet fragments into filaments, which in turn form cores. However, the material must reach a certain critical density before the evolution changes from being field dominated to being matter dominated. We measure the sheet surface density and the magnetic field strength at that transition for the first time and show consistency with an analytical prediction that had previously gone untested for over 50 yr.

Published
2023
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27. Kinematical Constraint on Eccentricity in the Protoplanetary Disk MWC 758 with ALMA

Author

I-Hsuan Genevieve Kuo, Hsi-Wei Yen, Pin-Gao Gu, and Tze-En Chang

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

We analyzed the archival data of the 13CO and C18O J = 3 − 2 emission lines in the protoplanetary disk around MWC 758 obtained with the Atacama Large Millimeter/submillimeter Array to discuss possible planet–disk interaction and non-Keplerian motion in the disk. We performed fitting of a Keplerian disk model to the observational data and measured the velocity deviations from the Keplerian rotation. We found significant velocity deviations around the inner cavity in the MWC 758 disk. We examined several possibilities that may cause the velocity deviations, such as pressure gradient, height of the emitting layer, infall motion, inner warp, and eccentricity in the disk. We found that the combination of an eccentric orbital motion with eccentricity of 0.1 ± 0.04 at the radius of the inner cavity and an infalling flow best explains the observed velocity deviations. Our kinematically constrained eccentricity of the gas orbital motion close to the inner cavity is consistent with the eccentricity of the dust ring around the inner cavity measured in the submillimeter continuum emission. Our results hint at strong dust–gas coupling around the inner cavity and presence of a gas giant planet inside the inner cavity in the MWC 758 disk.

Published
2022

28. ALMA band-1 receiver: first light, performance, and road to completion

Author

Yau De Huang, Yuh-Jing Hwang, Chau-Ching Chiong, Hsi-Wei Yen, Patrick M. Koch, Chi-Den Huang, Bill Liu, Cheng Lin Chen, Jwu Jiunn Tsai, Wei-Ling Hsiung, Li-Pin Chi, Chin-Ting Ho, Chao-Chin Wang, Chen Chien, You-Hua Chu, Paul Ho, Francisca Kemper, Alvaro Gonzalez, Satoru Iguchi, Yoshi Uzawa, Daisuke Iono, Hiroshi Nagai, John Effland, Kamaljeet Saini, Marian Pospieszalski, Doug Henke, Keith K. Yeung, Ricardo Finger, Valeria Tapia, Nicolas Reyes, Giorgio Siringo, Gianni Marconi, and Rodrigo Cabezas

Published
2022

29. A VLA View of the Flared, Asymmetric Disk around the Class 0 Protostar L1527 IRS

Author

Patrick D. Sheehan, John J. Tobin, Zhi-Yun Li, Merel L. R. van ’t Hoff, Jes K. Jørgensen, Woojin Kwon, Leslie W. Looney, Nagayoshi Ohashi, Shigehisa Takakuwa, Jonathan P. Williams, Yusuke Aso, Sacha Gavino, Itziar de Gregorio-Monsalvo, Ilseung Han, Chang Won Lee, Adele Plunkett, Rajeeb Sharma, Yuri Aikawa, Shih-Ping Lai, Jeong-Eun Lee, Zhe-Yu Daniel Lin, Kazuya Saigo, Kengo Tomida, and Hsi-Wei Yen

Subjects
STAR-FORMING REGIONS, FOS: Physical sciences, Astronomy and Astrophysics, SUBSTRUCTURES, YOUNG STELLAR OBJECTS, Astrophysics - Astrophysics of Galaxies, EVOLUTION, MOLECULES, CONTINUUM, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, GAS, Astrophysics of Galaxies (astro-ph.GA), ALMA, MASSES, Solar and Stellar Astrophysics (astro-ph.SR), INNER ENVELOPE
Abstract

We present high resolution Karl G. Jansky Very Large Array (VLA) observations of the protostar L1527 IRS at 7 mm, 1.3 cm, and 2 cm wavelengths. We detect the edge-on dust disk at all three wavelengths and find that it is asymmetric, with the southern side of the disk brighter than the northern side. We confirm this asymmetry through analytic modeling and also find that the disk is flared at 7 mm. We test the data against models including gap features in the intensity profile, and though we cannot rule such models out, they do not provide a statistically significant improvement in the quality of fit to the data. From these fits, we can however place constraints on allowed properties of any gaps that could be present in the true, underlying intensity profile. The physical nature of the asymmetry is difficult to associate with physical features due to the edge-on nature of the disk, but could be related to spiral arms or asymmetries seen in other imaging of more face-on disks., 20 pages, 5 figures, 3 tables; accepted for publication in the Astrophysical Journal

Published
2022

30. Formation of the SDC13 hub-filament system: a cloud–cloud collision imprinted on the multiscale magnetic field

Author

Jia-Wei Wang, Patrick M. Koch, Ya-Wen Tang, Gary A. Fuller, Nicolas Peretto, Gwenllian M. Williams, Hsi-Wei Yen, Han-Tsung Lee, and Wei-An Chen

Subjects
Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics
Abstract

Hub-filament systems (HFSs) are potential sites of protocluster and massive star formation, and play a key role in mass accumulation. We report JCMT POL-2 850 $\mu$m polarization observations toward the massive HFS SDC13. We detect an organized magnetic field near the hub center with a cloud-scale "U-shape" morphology following the western edge of the hub. Together with larger-scale APEX 13CO and PLANCK polarization data, we find that SDC13 is located at the convergent point of three giant molecular clouds (GMCs) along a large-scale, partially spiral-like magnetic field. The smaller "U-shape" magnetic field is perpendicular to the large-scale magnetic field and the converging GMCs. We explain this as the result of a cloud-cloud collision. Within SDC13, we find that local gravity and velocity gradients point toward filament ridges and hub center. This suggests that gas can locally be pulled onto filaments and overall converges to the hub center. A virial analysis of the central hub shows that gravity dominates magnetic and kinematic energy. Combining large- and small-scale analyses, we propose that SDC13 is initially formed from a collision of clouds moving along the large-scale magnetic field. In the post-shock regions, after the initial turbulent energy has dissipated, gravity takes over and starts to drive the gas accretion along the filaments toward the hub center., Comment: 34 pages, 25 figures, 3 tables

Published
2022

31. 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

32. 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

33. 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

34. Effects of magnetic field orientations in dense cores on gas kinematics in protostellar envelopes

Author

Aashish Gupta, Hsi-Wei Yen, Patrick Koch, Pierre Bastien, Tyler L. Bourke, Eun Jung Chung, Tetsuo Hasegawa, Charles L. H. Hull, Shu-ichiro Inutsuka, Jungmi Kwon, Woojin Kwon, Shih-Ping Lai, Chang Won Lee, Chin-Fei Lee, Kate Pattle, Keping Qiu, Mehrnoosh Tahani, Motohide Tamura, and Derek Ward-Thompson

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

Theoretically, misalignment between the magnetic field and rotational axis in a dense core is considered to be dynamically important in the star formation process, however, extent of this influence remains observationally unclear. For a sample of 32 Class 0 and I protostars in the Perseus Molecular Cloud, we analyzed gas motions using C$^{18}$O data from the SMA MASSES survey and the magnetic field structures using 850 $\mu$m polarimetric data from the JCMT BISTRO-1 survey and archive. We do not find any significant correlation between the velocity gradients in the C$^{18}$O emission in the protostellar envelopes at a 1,000 au scale and the misalignment between the outflows and magnetic field orientations in the dense cores at a 4,000 au scale, and there is also no correlation between the velocity gradients and the angular dispersions of the magnetic fields. However, a significant dependence on the misalignment angles emerges after we normalize the rotational motion by the infalling motion, where the ratios increase from $\lesssim1$ to $\gtrsim1$ with increasing misalignment angles. This suggests that the misalignment could prompt angular momentum transportation to the envelope scale but is not a dominant factor in determining the envelope rotation, and other parameters, like mass accretion in protostellar sources, also play an important role. These results remain valid after taking into account projection effects. The comparison between our estimated angular momentum in the protostellar envelopes and the sizes of the known protostellar disks suggests that significant angular momentum is likely lost between radii of $\sim$1,000-100 au in protostellar envelopes., Comment: Accepted by ApJ

Published
2022
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35. The JCMT BISTRO Survey: The Magnetic Field of the Barnard 1 Star-forming Region

Author

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

Published
2019
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36. A Multiscale Picture of the Magnetic Field and Gravity from a Large-scale Filamentary Envelope to Core-accreting Dust Lanes in the High-mass Star-forming Region W51

Author

Patrick M. Koch, Ya-Wen Tang, Paul T. P. Ho, Pei-Ying Hsieh, Jia-Wei Wang, Hsi-Wei Yen, Ana Duarte-Cabral, Nicolas Peretto, and Yu-Nung Su

Subjects
Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract

We present 230 GHz continuum polarization observations with the Atacama Large Milimeter/Submillimeter Array (ALMA) at a resolution of 0$\farcs1$ ($\sim 540$~au) in the high-mass star-forming regions W51 e2 and e8. These observations resolve a network of core-connecting dust lanes, marking a departure from earlier coarser more spherical continuum structures. At the same time, the cores do not appear to fragment further. Polarized dust emission is clearly detected. The inferred magnetic field orientations are prevailingly parallel to dust lanes. This key structural feature is analyzed together with the local gravitational vector field. The direction of local gravity is found to typically align with dust lanes. With these findings we derive a stability criterion that defines a maximum magnetic field strength that can be overcome by an observed magnetic field-gravity configuration. Equivalently, this defines a minimum field strength that can stabilize dust lanes against a radial collapse. We find that the detected dust lanes in W51 e2 and e8 are stable, hence possibly making them a fundamental component in the accretion onto central sources, providing support for massive star formation models without the need of large accretion disks. When comparing to coarser resolutions, covering the scales of envelope, global, and local collapse, we find recurring similarities in the magnetic field structures and their corresponding gravitational vector fields. These self-similar structures point at a multi-scale collapse-within-collapse scenario until finally the scale of core-accreting dust lanes is reached where gravity is entraining the magnetic field and aligning it with the dust lanes., accepted for publication in ApJ

Published
2022

37. 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

38. 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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39. The JCMT BISTRO survey: alignment between outflows and magnetic fields in dense cores/clumps

Author

Tie Liu, Shu-ichiro Inutsuka, Ilseung Han, Chakali Eswaraiah, Eun Jung Chung, Mehrnoosh Tahani, Chuan-Peng Zhang, Hiroko Shinnaga, Keping Qiu, Hong-Li Liu, Doug Johnstone, Miju Kang, James Di Francesco, Charles L. H. Hull, Derek Ward-Thompson, Chang Won Lee, Hiro Saito, Martin Houde, A-Ran Lyo, Florian Kirchschlager, Jungmi Kwon, Hsi-Wei Yen, Sarah Sadavoy, Tetsuo Hasegawa, Tao-Chung Ching, Jennifer Hatchell, Shih-Ping Lai, Ya-Wen Tang, Sam Falle, Woojin Kwon, Kate Pattle, Kee-Tae Kim, Motohide Tamura, Yasuo Doi, Simon Coudé, Pham Ngoc Diep, Ji-hyun Kang, Nagayoshi Ohashi, Gary A. Fuller, Pierre Bastien, Xindi Tang, Patrick M. Koch, Ray S. Furuya, Takashi Onaka, Archana Soam, and Chin-Fei Lee

Subjects
protostars, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Eddy current brake, Astrophysics, 01 natural sciences, star formation, interstellar magnetic fields, 0103 physical sciences, Astronomical interferometer, Astrophysics::Solar and Stellar Astrophysics, Protostar, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Star formation, Turbulence, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Magnetic field, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Outflow, Magnetohydrodynamics, star forming regions
Abstract

We compare the directions of molecular outflows of 62 low-mass Class 0 and I protostars in nearby (, 27 pages, 14 figures, Accepted by ApJ

Published
2021

40. The Circumnuclear Disk Revealed by ALMA. I. Dense Clouds and Tides in the Galactic Center

Author

Patrick M. Koch, Sergio Martín, Sara C. Beck, Paul T. P. Ho, Ya-Wen Tang, Hsi-Wei Yen, John M. Carpenter, Nanase Harada, Woong-Tae Kim, Jean L. Turner, and Pei-Ying Hsieh

Subjects
Physics, Supermassive black hole, 010504 meteorology & atmospheric sciences, Galactic Center, Velocity dispersion, Order (ring theory), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Submillimeter Array, Astrophysics - Astrophysics of Galaxies, Virial theorem, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Gravitational collapse, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

Utilizing the Atacama Large Millimeter/submillimeter Array (ALMA), we present CS line maps in five rotational lines ($J_{\rm u}=7, 5, 4, 3, 2$) toward the circumnuclear disk (CND) and streamers of the Galactic Center. Our primary goal is to resolve the compact structures within the CND and the streamers, in order to understand the stability conditions of molecular cores in the vicinity of the supermassive black hole (SMBH) Sgr A*. Our data provide the first homogeneous high-resolution ($1.3'' = 0.05$ pc) observations aiming at resolving density and temperature structures. The CS clouds have sizes of $0.05-0.2$ pc with a broad range of velocity dispersion ($\sigma_{\rm FWHM}=5-40$ km s$^{-1}$). The CS clouds are a mixture of warm ($T_{\rm k}\ge 50-500$ K, n$_{\rm H_2}$=$10^{3-5}$ cm$^{-3}$) and cold gas ($T_{\rm k}\le 50$ K, n$_{\rm H_2}$=$10^{6-8}$ cm$^{-3}$). A stability analysis based on the unmagnetized virial theorem including tidal force shows that $84^{+16}_{-37}$ % of the total gas mass is tidally stable, which accounts for the majority of gas mass. Turbulence dominates the internal energy and thereby sets the threshold densities $10-100$ times higher than the tidal limit at distance $\ge 1.5$ pc to Sgr A*, and therefore, inhibits the clouds from collapsing to form stars near the SMBH. However, within the central $1.5$ pc, the tidal force overrides turbulence and the threshold densities for a gravitational collapse quickly grow to $\ge 10^{8}$ cm$^{-3}$., Comment: accepted for publication in ApJ

Published
2021
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41. 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

42. Kinematical signs of dust trapping and feedback in a local pressure bump in the protoplanetary disk around HD 142527 revealed with ALMA

Author

Pin-Gao Gu and Hsi-Wei Yen

Subjects
010504 meteorology & atmospheric sciences, Continuum (design consultancy), FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Protoplanetary disk, 01 natural sciences, Submillimeter Array, Spectral line, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Emission spectrum, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Cosmic dust, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Spectral index, Astronomy and Astrophysics, Mass ratio, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We analyzed the archival data of the continuum emission at six wavelengths from 3 to 0.4 mm and 13CO and C18O (1-0, 2-1, and 3-2) lines in the protoplanetary disk around HD 142527 obtained with the Atacama Large Millimeter/submillimeter Array. We performed fitting to the spectral energy distributions obtained at the six wavelengths with the gray-body slab models to estimate the distributions of the dust surface density and spectral index of dust absorption coefficient beta. We also estimated the distribution of the gas column density by fitting the C18O spectra and measured the disk rotation by fitting the Keplerian disk models to the C18O data. We found super- and sub-Keplerian rotation inside and outside the dust ring in the northwest in the HD 142527 disk, suggestive of the presence of a local pressure bump. In comparison with our estimated dust and gas distributions, the location of the pressure bump is coincident with the region showing a three times higher dust density and a three times lower gas-to-dust mass ratio than the mean values in the disk, suggesting dust trapping in the pressure bump. Nevertheless, there is no correlation between our derived beta distribution and the location of the pressure bump. In addition, we found that the width of the dust ring is comparable or larger than the width of the pressure bump, which could suggest that dust feedback is significant in the pressure bump., 19 pages, 12 figures, Accepted by ApJ

Published
2020

43. Which Part of Dense Cores Feeds Material to Protostars? The Case of L1489 IRS

Author

Jinshi Sai, Nagayoshi Ohashi, Anaëlle J. Maury, Sébastien Maret, Hsi-Wei Yen, Yusuke Aso, Mathilde Gaudel, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University-Smithsonian Institution, 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 ), 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, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Solar and Stellar Astrophysics, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

We have conducted mapping observations ($\sim 2'\times2'$) of the Class I protostar L1489 IRS using the 7-m array of the Atacama Compact Array (ACA) and the IRAM-30m telescope in the $\mathrm{C^{18}O}$ 2-1 emission to investigate the gas kinematics on 1000-10,000 au scales. The $\mathrm{C^{18}O}$ emission shows a velocity gradient across the protostar in a direction almost perpendicular to the outflow. The radial profile of the peak velocity was measured from a $\mathrm{C^{18}O}$ position-velocity diagram cut along the disk major axis. The measured peak velocity decreases with radius at a radii of $\sim$1400-2900 au, but increases slightly or is almost constant at radii of $r\gtrsim$2900 au. Disk-and-envelope models were compared with the observations to understand the nature of the radial profile of the peak velocity. The measured peak velocities are best explained by a model where the specific angular momentum is constant within a radius of 2900 au but increases with radius outside 2900 au. We calculated the radial profile of the specific angular momentum from the measured peak velocities, and compared it to analytic models of core collapse. The analytic models reproduce well the observed radial profile of the specific angular momentum and suggest that material within a radius of $\sim$4000-6000 au in the initial dense core has accreted to the central protostar. Because dense cores are typically $\sim$10,000-20,000 au in radius, and as L1489 IRS is close to the end of mass accretion phase, our result suggests that only a fraction of a dense core eventually forms a star., 23 pages, 11 figures, accepted for publication in The Astrophysical Journal

Published
2022

44. 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

45. Disk structure around the Class I protostar L1489 IRS revealed by ALMA: a warped disk system

Author

Kengo Tomida, Hsi-Wei Yen, Kazuya Saigo, Kohji Tomisaka, Yusuke Aso, Masahiro N. Machida, Tomoaki Matsumoto, Nagayoshi Ohashi, Yuri Aikawa, Ippei Kurose, Shigehisa Takakuwa, and Jinshi Sai

Subjects
010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Rotation, 01 natural sciences, Submillimeter Array, 0103 physical sciences, Protostar, Continuum (set theory), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Line (formation), Physics, Earth and Planetary Astrophysics (astro-ph.EP), Velocity gradient, Astronomy and Astrophysics, Radius, Astrophysics - Astrophysics of Galaxies, Accretion (astrophysics), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

We have observed the Class I protostar L1489 IRS with the Atacama Millimeter/submillimeter Array (ALMA) in Band 6. The C$^{18}$O $J=$2-1 line emission shows flattened and non-axisymmetric structures in the same direction as its velocity gradient due to rotation. We discovered that the C$^{18}$O emission shows dips at a radius of ~200-300 au while the 1.3 mm continuum emission extends smoothly up to r~400 au. At the radius of the C$^{18}$O dips, the rotational axis of the outer portion appears to be tilted by ~15 degrees from that of the inner component. Both the inner and outer components with respect to the C$^{18}$O dips exhibit the $r^{-0.5}$ Keplerian rotation profiles until r~600 au. These results not only indicate that a Keplerian disk extends up to ~600 au but also that the disk is warped. We constructed a three dimensional warped disk model rotating at the Keplerian velocity, and demonstrated that the warped disk model reproduces main observed features in the velocity channel maps and the PV diagrams. Such a warped disk system can form by mass accretion from a misaligned envelope. We also discuss a possible disk evolution scenario based on comparisons of disk radii and masses between Class I and Class II sources., 26 pages, 18 figures, accepted by ApJ

Published
2020

46. Circumbinary Disks of the Protostellar Binary Systems in the L1551 Region

Author

Hsi-Wei Yen, Kazuya Saigo, Masao Saito, Jeremy Lim, Paul T. P. Ho, Shigehisa Takakuwa, Nagayoshi Ohashi, Leslie W. Looney, and Tomoaki Matsumoto

Subjects
Physics, Spiral galaxy, 010504 meteorology & atmospheric sciences, Star formation, Continuum (design consultancy), Lagrangian point, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Rotation, Astrophysics - Astrophysics of Galaxies, 01 natural sciences, Interstellar medium, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Protostar, Circumbinary planet, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract

We report ALMA Cycle 4 observations of the Class I binary protostellar system L1551 IRS 5 in the 0.9-mm continuum emission, C18O (J=3-2), OCS (J=28-27), and four other Band 7 lines. At ~0.07" (= 10 au) resolution in the 0.9 mm emission, two circumstellar disks (CSDs) associated with the binary protostars are separated from the circumbinary disk (CBD). The CBD is resolved into two spiral arms, one connecting to the CSD around the northern binary source, Source N, and the other to Source S. As compared to the CBD in the neighboring protobinary system L1551 NE, the CBD in L1551 IRS 5 is more compact (r ~150 au) and the m=1 mode of the spirals found in L1551 NE is less obvious in L1551 IRS 5. Furthermore, the dust and molecular-line brightness temperatures of CSDs and CBD reach >260 K and >100 K, respectively, in L1551 IRS 5, much hotter than those in L1551 NE. The gas motions in the spiral arms are characterized by rotation and expansion. Furthermore, the transitions from the CBD to the CSD rotations at around the L2 and L3 Lagrangian points and gas motions around the L1 point are identified. Our numerical simulations reproduce the observed two spiral arms and expanding gas motion as a result of gravitational torques from the binary, transitions from the CBD to the CSD rotations, and the gas motion around the L1 point. The higher temperature in L1551 IRS 5 likely reflects the inferred FU-Ori event., 22 pages, 13 figures

Published
2020
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47. Dust polarized emission observations of NGC 6334; BISTRO reveals the details of the complex but organized magnetic field structure of the high-mass star-forming hub-filament network

Author

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

Subjects
010504 meteorology & atmospheric sciences, ISM: structure, FOS: Physical sciences, Context (language use), Astrophysics, 01 natural sciences, ISM: clouds, Spectral line, Protein filament, 0103 physical sciences, 010303 astronomy & astrophysics, James Clerk Maxwell Telescope, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, polarization, stars: formation, Star formation, Astronomy and Astrophysics, Ridge (differential geometry), Polarization (waves), Astrophysics - Astrophysics of Galaxies, Stars, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), submillimeter: ISM, ISM: magnetic fields
Abstract

[Abridged] Filaments and hubs have received special attention recently thanks to studies showing their role in star formation. While the column density and velocity structures of both filaments and hubs have been studied, their magnetic fields (B-field) are not yet characterized. We aim to understand the role of the B-field in the dynamical evolution of the NGC 6334 hub-filament network. We present new observations of the dust polarized emission at 850$\mu$m towards NGC 6334 obtained with the JCMT/POL-2. We study the distribution and dispersion of the polarized intensity ($PI$), the polarization fraction ($PF$), and the B-field angle ($\theta_{B}$). We derive the power spectrum of the intensity and $\theta_{B}$ along the ridge crest. Our analyses show a complex B-field structure when observed over the whole region ($\sim10$ pc), however, at smaller scales ($\sim1$ pc), $\theta_{B}$ varies coherently along the filaments. The observed power spectrum of $\theta_{B}$ can be well represented with a power law function with a slope $-1.33\pm0.23$, which is $\sim20\%$ shallower than that of $I$. This result is compatible with the properties of simulated filaments and may indicate the processes at play in the formation of filaments. $\theta_{B}$ rotates from being mostly perpendicular to the filament crests to mostly parallel as they merge with the hubs. This variation of $\theta_{B}$ may be tracing local velocity flows of matter in-falling onto the hubs. Our analysis suggests a variation of the energy balance along the crests of these filaments, from magnetically critical/supercritical at their far ends to magnetically subcritical near the hubs. We detect an increase of $PF$ towards the high-column density star cluster-forming hubs that may result from the increase of grain alignment efficiency due to stellar radiation from the newborn stars., Comment: Accepted for publication in Astronomy & Astrophysics

Published
2020
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48. The Nuclear Filaments inside the Circumnuclear Disk in the Central 0.5 pc of the Galactic center

Author

Nanase Harada, Hsi-Wei Yen, Patrick M. Koch, Ya-Wen Tang, Paul T. P. Ho, Pei-Ying Hsieh, and Woong-Tae Kim

Subjects
Physics, 010504 meteorology & atmospheric sciences, Galactic Center, FOS: Physical sciences, Astronomy and Astrophysics, Radius, Astrophysics, 01 natural sciences, Submillimeter Array, Astrophysics - Astrophysics of Galaxies, Interferometry, Orbit, Space and Planetary Science, Primary (astronomy), Astrophysics of Galaxies (astro-ph.GA), 0103 physical sciences, Millimeter, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Line (formation)
Abstract

We present CS(7-6) line maps toward the central parsec of the Galactic Center (GC), conducted with the Atacama Large Millimeter/submillimeter Array (ALMA). The primary goal is to find and characterize the gas structure in the inner cavity of the circumnuclear disk (CND) in high resolution (1.3"=0.05 pc). Our large field-of-view mosaic maps -- combining interferometric and single-dish data that recover extended emission - provide a first homogeneous look to resolve and link the molecular streamers in the CND with the neutral nuclear filaments newly detected within the central cavity of the CND. We find that the nuclear filaments are rotating with Keplerian velocities in a nearly face-on orbit with an inclination angle of ~10-20 degree (radius, 6 pages, 4 figures, accepted in ApJL

Published
2019

49. No Impact of Core-scale Magnetic Field, Turbulence, or Velocity Gradient on Sizes of Protostellar Disks in Orion A

Author

Bo Zhao, Patrick M. Koch, Hsi-Wei Yen, and Aashish Gupta

Subjects
Physics, Angular momentum, Star formation, Velocity gradient, Turbulence, Continuum (design consultancy), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Computational physics, Magnetic field, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Protostar, Astrophysics::Earth and Planetary Astrophysics, Magnetohydrodynamics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract

We compared the sizes and fluxes of a sample of protostellar disks in Orion A measured with the ALMA 0.87 mm continuum data from the VANDAM survey with the physical properties of their ambient environments on the core scale of 0.6 pc estimated with the GBT GAS NH3 and JCMT SCUPOL polarimetric data. We did not find any significant dependence of the disk radii and continuum fluxes on a single parameter on the core scale, such as the non-thermal line width, magnetic field orientation and strength, or magnitude and orientation of the velocity gradient. Among these parameters, we only found a positive correlation between the magnitude of the velocity gradient and the non-thermal line width. Thus, the observed velocity gradients are more likely related to turbulent motion but not large-scale rotation. Our results of no clear dependence of the disk radii on these parameters are more consistent with the expectation from non-ideal MHD simulations of disk formation in collapsing cores, where the disk size is self-regulated by magnetic braking and diffusion, compared to other simulations which only include turbulence and/or a magnetic field misaligned with the rotational axis. Therefore, our results could hint that the non-ideal MHD effects play a more important role in the disk formation. Nevertheless, we cannot exclude the influences on the observed disk size distribution by dynamical interaction in a stellar cluster or amounts of angular momentum on the core scale, which cannot be probed with the current data., Comment: 17 pages, 4 figures, 1 Table. Accepted by ApJ

Published
2021

50. 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

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