Poster - Splinter SOFIA   (H 3006)

Extragalactic Magnetism with SOFIA (SALSA Legacy Program)

A. Borlaff, E. Lopez-Rodriguez, R. Beck, S.A. Mao
NASA Ames Research Center, Kavli Institute Stanford, MPIfR Bonn

The Survey of extragALactic magnetiSm with SOFIA (SALSA Legacy Program) used SOFIA/HAWC+ in the far-infrared (FIR) from 53 to 214 µm to observe 14 nearby (<20 Mpc) galaxies (i.e., spirals, starbursts, mergers, active galactic nuclei, and dwarfs) with resolved (5"–18"; 90 pc–1 kpc) imaging polarimetry. The analysis of the magnetic field (B-field) structure of spiral galaxies measured with FIR and radio synchrotron polarimetry at 3 and 6 cm with the VLA and Effelsberg telescopes demonstrates that FIR and radio wavelengths do not generally trace the same B-field morphology. B-fields associated with dense, dusty, turbulent star-forming regions (those traced at FIR) are less ordered than those in the warmer, less dense interstellar medium (those traced at radio). The FIR B-fields seem to be more sensitive to the activity of the star-forming regions and molecular clouds closer to the disk compared to the radio B-fields located in the broader disk of diffuse, warm, ionized gas. For starburst galaxies, we find that FIR polarization is a better tracer of the B-fields along the galactic outflows than radio polarization.