Description
Arp220 is the nearest and brightest ultraluminous infrared galaxy and thus represents an ideal laboratory for studies of star formation in the extreme environment of a massive galaxy merger. Arp220, in particular, hosts star formation at a rate of ~100 solar masses per year, most of which takes place in heavily obscured molecular disks around the nuclei of the two merging galaxies. We here report the detection of polarised dust emission at submm wavelengths from the SMA from these nuclei, indicating the presence of magnetic fields that are roughly aligned with the molecular disks. These magnetic fields may play a role in suppressing feedback and promoting enhanced star formation rates and efficiencies, leading to the starburst behaviour of this galaxy. We also discuss the prospects for further observations of polarised dust emission in other local ULIRGs, and conclude that such studies may provide new insights into the details of extreme star formation environments.
