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arXiv · 2503.20721

Imprints of Stellar Feedback on Magnetic Fields in the Iris Nebula NGC 7023

Ekta Sharma·Kate Pattle·Di Li·Chang Won Lee·Maheswar Gopinathan·Tao-Chung Ching·Mehrnoosh Tahani·Shinyoung Kim
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Abstract

We present 850 $\mu$m polarized continuum observations carried out with the POL-2 polarimeter mounted on the James Clerk Maxwell Telescope (JCMT) towards NGC 7023 located in the Cepheus Flare region. NGC 7023 is a reflection nebula powered by a Herbig Ae Be star HD 200775 and also identified as a hub in the hub-filament cloud, LDN 1172/1174. We detect submillimetre emission well towards the northern (identified as C1) and the eastern region of the reflection nebula. We investigated the polarization structure and the magnetic field (B-field) morphology, which is found to be curved and follows the clump morphology. The comparison of the B-field morphology at the clump scales ($\sim$0.02 pc) with that of the envelope ($\sim$0.5 pc) suggests that the field lines are not preserved from envelope to clump scales, implying that an external factor may be responsible for disturbing the B-field structure. We estimated a magnetic field strength of 179$\pm$50 $\mu$G in the starless core, 121$\pm$34 $\mu$G in the protostellar core with a class I source and 150$\pm$42 $\mu$G in the protostellar core with a class II source using the $N_{2}H^{+}$ (1-0) line observed with 13.7 m single dish radio telescope at Taeduk Radio Astronomy Observatory (TRAO). The stability analysis using these B-field strengths gives magnetically sub-critical values, while the magnetic, gravitational, and outflow kinetic energies are roughly balanced. We also suggest that the reordering of the magnetic field lines could be due to the interaction with the already evolved high-velocity outflow gas around the central star, which hints at the presence of outflow feedback.

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Ekta Sharma, Kate Pattle, Di Li, Chang Won Lee, Maheswar Gopinathan, Tao-Chung Ching, Mehrnoosh Tahani, Shinyoung Kim. 2025-03-26. Imprints of Stellar Feedback on Magnetic Fields in the Iris Nebula NGC 7023. https://arxiv.org/abs/2503.20721

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