Research Article
Magnetic Field Structure and Star Formation Efficiency in Clump-Scale Star-Forming Regions: A JCMT POL-2 Analysis
Issue:
Volume 14, Issue 2, June 2026
Pages:
20-28
Received:
16 June 2026
Accepted:
27 June 2026
Published:
17 July 2026
DOI:
10.11648/j.ijass.20261402.11
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Abstract: We present a clump-scale observational study of magnetic-field structure and star formation efficiency (SFE) using published dust polarization observations obtained with the James Clerk Maxwell Telescope (JCMT) POL-2 instrument. The sample consists of 11 predominantly high-mass star-forming clumps associated with clustered and filamentary molecular environments. Plane-of-sky magnetic-field strengths derived from published Davis-Chandrasekhar-Fermi (DCF) analyses were examined together with magnetic-field morphology and star formation efficiency measurements compiled from the literature. The results show that the relationship between magnetic-field strength and star formation efficiency is not characterized by a simple monotonic trend. Spearman rank correlation analysis indicates a weak and statistically insignificant negative relationship between magnetic-field strength and SFE, while the observed -SFE distribution exhibits substantial scatter across the sample. Regions with comparable magnetic-field strengths therefore display significantly different star formation efficiencies, indicating that magnetic-field strength alone does not uniquely regulate star formation at clump scales. Representative JCMT POL-2 polarization maps show that the sampled regions are dominated by ordered hourglass-like and partially pinched magnetic-field morphologies. Hourglass-like structures are generally associated with intermediate to strong magnetic fields and relatively low or moderate efficiencies, whereas pinched morphologies occupy a broader range of SFE values. The results support a scale-dependent interpretation of magnetic regulation in which magnetic fields influence collapse geometry and dense gas structure, while star formation efficiency emerges from the coupled interaction of gravity, fragmentation, turbulence, filamentary accretion, and stellar feedback within dynamically evolving molecular clumps.
Abstract: We present a clump-scale observational study of magnetic-field structure and star formation efficiency (SFE) using published dust polarization observations obtained with the James Clerk Maxwell Telescope (JCMT) POL-2 instrument. The sample consists of 11 predominantly high-mass star-forming clumps associated with clustered and filamentary molecular...
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Research Article
Heliospheric Origins of Intense Geomagnetic Storms: Evidence from Solar Cycles 23, 24, and Rising Phase of 25
Issue:
Volume 14, Issue 2, June 2026
Pages:
29-38
Received:
21 June 2026
Accepted:
3 July 2026
Published:
24 July 2026
DOI:
10.11648/j.ijass.20261402.12
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Abstract: Understanding the drivers of geomagnetic storm activity is essential for advancing space weather forecasting and mitigating the impacts of solar-terrestrial disturbances on technological systems. In this study, the influence of key solar and interplanetary parameters on geomagnetic storm occurrence was investigated through a correlation analysis between the yearly frequency of geomagnetic storms and selected indicators of solar and heliospheric activity. The parameters examined include hard X-ray solar flares, solar wind plasma pressure, coronal mass ejection (CME) occurrence, the F10.7 solar radio flux index, and the interplanetary magnetic field (IMF). The results reveal statistically significant positive relationships between geomagnetic storm frequency and all investigated parameters, indicating that enhanced solar and interplanetary activity generally promotes increased geomagnetic disturbances. Among the studied variables, the strongest correlation was observed between geomagnetic storm frequency and the yearly mean IMF (r = 0.83), emphasizing the dominant role of interplanetary magnetic field conditions in storm generation and magnetosphere-solar wind coupling processes. A strong positive correlation was also found with solar wind plasma pressure (r = 0.73), suggesting that elevated solar wind dynamic pressure significantly contributes to geomagnetic storm occurrence. The F10.7 solar radio flux index exhibited a substantial positive correlation (r = 0.67), indicating that higher levels of solar activity are associated with increased geomagnetic storm frequency. Similarly, CME occurrence showed a positive correlation (r = 0.63), confirming the important contribution of large-scale solar eruptive events to geomagnetic disturbances. Furthermore, hard X-ray solar flare activity demonstrated a positive association with storm occurrence, highlighting the role of energetic solar eruptions in shaping space weather variability. The comparative analysis establishes the relative influence of the investigated parameters in the following order: IMF (r = 0.83) > Solar Wind Plasma Pressure (r = 0.73) > F10.7 Solar Flux (r = 0.67) > CME Occurrence (r = 0.63). These findings demonstrate that geomagnetic storm activity is governed by a complex interplay between solar activity and interplanetary conditions, with IMF variability emerging as the most influential factor. The study contributes to a deeper understanding of solar-terrestrial interactions and provides valuable insights for improving predictive models of geomagnetic storm occurrence and space weather hazards.
Abstract: Understanding the drivers of geomagnetic storm activity is essential for advancing space weather forecasting and mitigating the impacts of solar-terrestrial disturbances on technological systems. In this study, the influence of key solar and interplanetary parameters on geomagnetic storm occurrence was investigated through a correlation analysis be...
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,
Jemima Ngozi Ogwo
