Speaker
Description
Galactic winds are essential in the baryonic cycle of galaxies with cosmic rays and magnetic fields possibly playing an important role. Their influence, however, is yet poorly constrained by observations. In this talk, I will present recent results obtained from radio continuum polarimetry observations of the nearby edge-on galaxy NGC 4217, observing both with the Jansky Very Large Array and the LOw Frequency ARray. We discover a new 20-kpc radio superbubble with limb-brightening and with its base aligned with the X-shaped magnetic fields in the halo of this galaxy. We model the radio halo with cosmic-ray electron transport and find advection speeds between 300 km/s near the disc and 600 km/s in the halo. The energy injected by supernovae is enough to inflate the bubble, although the influence of an active galactic nucleus cannot be ruled out either. Such bubbles may be ubiquitous in star-forming galaxies showing the presence of bipolar outflows as a result of feedback.
| What is your career stage? | Tenured scientist |
|---|---|
| Which telescopes do you use / are you affiliated with? | VLA, LOFAR |
