Amanda Kepley (University of Virginia)

The Role of Magnetic Fields in the Interstellar Medium of Irregular Galaxies - Amanda Kepley Colloquium

ATNF Marsfield Lecture Theatre

Abstract

Irregular galaxies are the present day analogs of the high redshift
building blocks of galaxies like the Milky Way. The shallow potential
wells of irregular galaxies makes their interstellar medium a chaotic
system prone to disruption by star formation, interactions, and
mergers. An important, but oft-overlooked component of the
interstellar medium of irregulars is their magnetic field. Previous
observations suggest that irregulars have a wide range magnetic field
strengths and properties. To increase the number of irregulars with
detailed observations of their magnetic fields, we present detailed
observations of two irregular galaxies with the VLA and WSRT: NGC
4214 and NGC 1569.The magnetic field of NGC 1569 is shaped by the
outflow of gas from this galaxy, but may play a significant role in
channeling gas out of the central regions of the galaxy. The magnetic
field of NGC 4214 is mostly random and is not a dominant source of
pressure. We will place these fields into the context of the
interstellar medium of these galaxies. Finally, we will draw
conclusions on the role of magnetic fields in irregular galaxies in
general.