Invited Presentation
When higher angular resolution might not resolve the emission: the case of the magnetic field in G31.41+0.31
Presenter: Maite Beltran (INAF-Osservatorio Astrofisico di Arcetri)
Dust polarization observations of the massive protocluster G31.41+0.31, containing at least four embedded massive proto-stars, carried out with the SMA at 870 microns and 1" (3750 au) have revealed one of the most clear examples up to date of an hourglass-shaped magnetic field in the high-mass regime. ALMA observations at 1.3 mm and at a higher angular resolution of 0.24" (900 au) have confirmed these results, suggesting that the magnetic field maintains an hourglass-shaped morphology down to scales of < 1000 au. New ALMA observations at 0.067" (250 au) at 1.3 mm and 3.1 mm have revealed that the self-similarity observed at lower angular resolution still holds at circumstellar scales, and this is supported by the modelling of the polarized emission, which confirms the poloidal shape of the magnetic field. However, the self-similarity of the magnetic field observed at the smallest scales might be produced by the large opacity of the dust emission that prevents the detection of any inhomogeneity in the core and would not allow us to proper trace the magnetic field down to circumstellar scales.
asiaa.sinica.edu.tw