تقرير
Alignment of dense molecular core morphology and velocity gradients with ambient magnetic fields
| العنوان: | Alignment of dense molecular core morphology and velocity gradients with ambient magnetic fields |
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| المؤلفون: | Pandhi, A., Friesen, R. K., Fissel, L., Pineda, J. E., Caselli, P., Chen, M. C-Y., Di Francesco, J., Ginsburg, A., Kirk, H., Myers, P. C., Offner, S. S. R., Punanova, A., Quan, F., Redaelli, E., Rosolowsky, E., Scibelli, S., Seo, Y. M., Shirley, Y. |
| سنة النشر: | 2023 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies, Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | Studies of dense core morphologies and their orientations with respect to gas flows and the local magnetic field have been limited to only a small sample of cores with spectroscopic data. Leveraging the Green Bank Ammonia Survey alongside existing sub-millimeter continuum observations and Planck dust polarization, we produce a cross-matched catalogue of 399 dense cores with estimates of core morphology, size, mass, specific angular momentum, and magnetic field orientation. Of the 399 cores, 329 exhibit 2D $\mathrm{v}_\mathrm{LSR}$ maps that are well fit with a linear gradient, consistent with rotation projected on the sky. We find a best-fit specific angular momentum and core size relationship of $J/M \propto R^{1.82 \pm 0.10}$, suggesting that core velocity gradients originate from a combination of solid body rotation and turbulent motions. Most cores have no preferred orientation between the axis of core elongation, velocity gradient direction, and the ambient magnetic field orientation, favouring a triaxial and weakly magnetized origin. We find, however, strong evidence for a preferred anti-alignment between the core elongation axis and magnetic field for protostellar cores, revealing a change in orientation from starless and prestellar populations that may result from gravitational contraction in a magnetically-regulated (but not dominant) environment. We also find marginal evidence for anti-alignment between the core velocity gradient and magnetic field orientation in the L1228 and L1251 regions of Cepheus, suggesting a preferred orientation with respect to magnetic fields may be more prevalent in regions with locally ordered fields. Comment: 33 pages, 28 figures, accepted to MNRAS |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stad2283 |
| URL الوصول: | http://arxiv.org/abs/2307.13022 |
| رقم الأكسشن: | edsarx.2307.13022 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/stad2283 |
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