Where stars form
Magnetic fields, cores and gas flows inside individual molecular clouds: Orion, Monoceros OB1, infrared dark clouds and the centre of NGC 253.
Inside a single cloud the field is measured with submillimetre polarimeters such as POL-2 on the JCMT and with ALMA, and compared with the gas motions traced by molecular lines. The question in each case is the same: does the field guide the gas into cores, or do gravity and turbulence win?
Results
What the papers report, in their own terms. Each item links to its source.
In Monoceros OB1 East the large-scale field is ordered. In the northern part it runs mostly along the filaments; the southern part has at least two regions with distinct field orientations.
Alina et al. 2022In the translucent high-latitude cloud MBM 12, column density structures change from parallel to perpendicular to the Planck field above a threshold column density.
N(H2) = 4.5 × 1021 cm-2
Vorster et al. 2026In the infrared dark cloud G34.43+0.24, JCMT POL-2 shows an ordered field close to perpendicular to the filament around its central clumps. The cloud is marginally critical, with mass-to-flux ratios near one in all three parts.
BPOS = 470 ± 190, 100 ± 40, 60 ± 34 µG (centre, north, south)
Soam et al. 2019JWST and ALMA show a compact hub-filament system in the protocluster G286.21+0.17, about 0.5 pc across, with at least four filaments converging on a dense hub. The filament accretion rates and the radial distribution of cores are consistent with competitive accretion.
filament accretion rates 7.6–11 × 10-5 M☉ yr-1
Dewangan et al. 2026
Monoceros OB1 East
The Planck field over the cloud and the regions where Alina et al. 2022 measured its strength and traced the gas motions.
NMNWNEShockABNENGC 2264Papers
19 entries from NASA ADS. All publications →
- 2026Discovery of a compact hub-filament system in G286.21 + 0.17 with JWST and ALMA: insights into protocluster formation and competitive accretionDewangan, Bhadari, Yadav, … Alina (9 of 20) et al.Monthly Notices of the Royal Astronomical Society, 552, stag1764 · arXiv:2605.14693
- 2026Hub-filament systems and the growth of massive stars: episodic accretion, clustered environments, and projection effectsMakarova, Alina, Padoan et al.arXiv e-prints, arXiv:2608.00441 · arXiv:2608.00441
- 2026B-FROST: B-Fields and star formation across scales with TRAO: CO abundances, dynamics, and relative orientations in the translucent high latitude cloud MBM12Vorster, Montillaud, Juvela, … Alina (7 of 17) et al.Astronomy and Astrophysics, 711, A157 · arXiv:2605.21101
- 2026MAJORS II: HCO+ and HCN abundances in W40Plume, Eden, Currie, … Alina (18 of 37) et al.Monthly Notices of the Royal Astronomical Society, 547, stag186 · arXiv:2601.19971
- 2025Magnetic Field of a Ring-like Molecular CloudAlina, Umirbayeva, Doi et al.The Astronomical Journal, 170, 152 · arXiv:2507.19281
- 2025The dust polarisation and magnetic field structure in the centre of NGC253 with ALMABelfiori, Paladino, Hughes, … Alina (5 of 10) et al.Astronomy and Astrophysics, 697, A24 · arXiv:2503.034934 cit.
- 2025Mass inflow structures in star formation from filaments to streamers: the unique field of Orion Molecular Cloud 3Juvela, Alina, Demyk et al.JWST Proposal. Cycle 4, 7433
- 2024The Magnetic Field in Quiescent Star-forming Filament G16.96+0.27Gu, Liu, Shen, … Alina (22 of 23) et al.The Astrophysical Journal, 976, 249 · arXiv:2410.159136 cit.
- 2024On the Scarcity of Dense Cores (n > 105 cm−3) in High-latitude Planck Galactic Cold ClumpsXu, Wang, Liu, … Alina (24 of 37) et al.The Astrophysical Journal Letters, 963, L9 · arXiv:2401.146583 cit.
- 2022Large-scale magnetic field in the Monoceros OB 1 east molecular cloudAlina, Montillaud, Hu et al.Astronomy and Astrophysics, 658, A90 · arXiv:2007.1534426 cit.
- 2021ALMA Survey of Orion Planck Galactic Cold Clumps (ALMASOP): Detection of Extremely High-density Compact Structure of Prestellar Cores and Multiple Substructures WithinSahu, Liu, Liu, … Alina (10 of 41) et al.The Astrophysical Journal Letters, 907, L15 · arXiv:2012.0873732 cit.
- 2019Multi-scale analysis of the Monoceros OB 1 star-forming region. II. Colliding filaments in the Monoceros OB1 molecular cloudMontillaud, Juvela, Vastel, … Alina (17 of 27) et al.Astronomy and Astrophysics, 631, A3 · arXiv:1909.0614529 cit.
- 2019Multi-scale analysis of the Monoceros OB 1 star-forming region. I. The dense core populationMontillaud, Juvela, Vastel, … Alina (17 of 27) et al.Astronomy and Astrophysics, 631, L1 · arXiv:1909.0378112 cit.
- 2019Magnetic Fields in the Infrared Dark Cloud G34.43+0.24Soam, Liu, Andersson, … Alina (34 of 43) et al.The Astrophysical Journal, 883, 95 · arXiv:1908.0362455 cit.
- 2019SCOPE: SCUBA-2 Continuum Observations of Pre-protostellar Evolution - survey description and compact source catalogueEden, Liu, Kim, … Alina (62 of 163) et al.Monthly Notices of the Royal Astronomical Society, 485, 2895 · arXiv:1902.1018043 cit.
- 2018Dust spectrum and polarisation at 850 μm in the massive IRDC G035.39-00.33Juvela, Guillet, Liu, … Alina (6 of 21) et al.Astronomy and Astrophysics, 620, A26 · arXiv:1809.0086427 cit.
- 2018A Holistic Perspective on the Dynamics of G035.39-00.33: The Interplay between Gas and Magnetic FieldsLiu, Li, Juvela, … Alina (37 of 57) et al.The Astrophysical Journal, 859, 151 · arXiv:1803.0945781 cit.
- 2018The TOP-SCOPE Survey of PGCCs: PMO and SCUBA-2 Observations of 64 PGCCs in the Second Galactic QuadrantZhang, Liu, Yuan, … Alina (22 of 26) et al.The Astrophysical Journal Supplement Series, 236, 49 · arXiv:1805.0388315 cit.
- 2018The TOP-SCOPE Survey of Planck Galactic Cold Clumps: Survey Overview and Results of an Exemplar Source, PGCC G26.53+0.17Liu, Kim, Juvela, … Alina (51 of 156) et al.The Astrophysical Journal Supplement Series, 234, 28 · arXiv:1711.0438265 cit.