What is the role of magnetic fields in sculpting the ISM at kiloparsec scales? This question is the driver behind the Legacy Program 'SOFIA heralds a new era of measuring the magnetic fields of galaxies' , led by Enrique Lopez Rodriguez (KIPAC/Stanford) and Ann Sui Mao (MPIfR). This survey consists of 50-220 microns polarimetric observations of a flux-limited sample of 17 nearby galaxies including starbursts, mergers, active galaxies, and spiral galaxies.
Far-IR emission probes the emission from magnetically aligned dust grains in high density cold regions, where star formation tends to occur. All targeted galaxies have rich archival data that will be used to quantify the effect of the multi-phase ISM and star formation regions in the B-field as traced by dust and synchrotron emission.
The HAWC+ data for targets M82, NGC 1097, NGC 2146, NGC 6946, Centaurus A, and Circinus are already public, and datasets are available from the IRSA archive , under program IDs 08_0012, 07_0032, and 07_0034. The legacy team will provide tools to analyze the data as the project develops; for now they have provided a script to generate polarization maps from the archival data.
Total flux (color scale) with measured polarization vectors (black lines), rotated by 90◦ to show the inferred magnetic field. Approximated locations of the inner-bar and starburst rings are shown. Streamlines show the magnetic field model that best describes the observed kpc-scale spiral magnetic field.