Astrophysical and Planetary Sciences Colloquium

Monday, November 01, 2021 at 12:40

Enrique Lopez Rodriguez, Stanford

"Extragalactic Magnetism Using Far-Infrared Polarimetry"

A Pretty Image from the Talk


Please note this talk will be virtual-only.

The evolution of galaxies is controlled by a delicate interplay between gravity, turbulence, feedback, and magnetic fields. Although most current empirical and theoretical approaches to understanding this interplay are mainly focused on gravitational forces and gas dynamics, magnetic fields indeed play a fundamental role in the interstellar medium (ISM), galactic dynamics, galactic winds, and intergalactic medium (IGM). Galaxies are known to host large-scale magnetic fields along the spiral arms and have magnetic field strengths of several microGauss with similar contributions from the random and ordered magnetic field components. To date, these results have mostly emerged from single wavelength regimes: radio synchrotron polarization tracing the magnetic field structure in the ionized diffuse gas. The Stratospheric Observatory For Infrared Astronomy (SOFIA) is key to provide a complete new picture of extragalactic magnetism by doing what only HAWC+, a far-infrared imaging polarimeter, can do: measuring magnetic fields in the dense ISM of galaxies.

Our team has recently shown that the radio and FIR polarization observations do not necessarily trace the same magnetic field structure in the ISM of galaxies, rather the star formation rate, the physical components of the ISM and its turbulence affect the magnetic fields in galaxies. We have detected large-scale ordered B-fields in the host galaxies of active galactic nuclei, a magnetic field tightly following the molecular warped disk of a merger galaxy, and magnetic fields along the outflows of starburst galaxies, which are likely responsible for magnetizing the IGM. These results have contributed to open a new window of exploration on galaxy evolution. In this talk I will present the results of our SOFIA Legacy Program to quantifying the effect of galaxy dynamics, gas kinematics, and multi-phase ISM on the magnetic fields of galaxies.


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