| Abstract |
We present the analysis of the magnetic field ($B$-field) structure of galaxies measured with far-infrared (FIR) and radio (3 and 6 cm) polarimetric observations. We use the first data release of the Survey on extragALactic magnetiSm with SOFIA (SALSA) of 14 nearby ($<20$ Mpc) galaxies with resolved (5 arcsec-18 arcsec; $90$ pc--$1$ kpc) imaging polarimetric observations using HAWC+/SOFIA from $53$ to $214$ \um. We compute the magnetic pitch angle ($\Psi_{B}$) profiles as a function of the galactrocentric radius. We introduce a new magnetic alignment parameter ($\zeta$) to estimate the disordered-to-ordered $B$-field ratio in spiral $B$-fields. We find FIR and radio wavelengths to not generally trace the same $B$-field morphology in galaxies. The $\Psi_{B}$ profiles tend to be more ordered with galactocentric radius in radio ($\zeta_{\rm{6cm}} = 0.93\pm0.03$) than in FIR ($\zeta_{\rm{154\mu m}} = 0.84\pm0.14$). For spiral galaxies, FIR $B$-fields are $2-75$\% more turbulent than the radio $B$-fields. For starburst galaxies, we find that FIR polarization is a better tracer of the $B$-fields along the galactic outflows than radio polarization. Our results suggest that the $B$-fields associated with dense, dusty, turbulent star-forming regions, those traced at FIR, are less ordered than warmer, less-dense regions, those traced at radio, of the interstellar medium. The FIR $B$-fields seem to be more sensitive to the activity of the star-forming regions and the morphology of the molecular clouds within a vertical height of few hundred pc in the disk of spiral galaxies than the radio $B$-fields. |
| Authors |
Alejandro S. Borlaff  , Enrique López-Rodríguez , R. Beck , Susan E. Clark , Evangelia Ntormousi , Konstantinos Tassis , Sergio Martin-Alvarez , Mehrnoosh Tahani , Daniel A. Dale  , Ignacio del Moral-Castro , Julia Roman-Duval , Pamela M. Marcum , J. E. Beckman , Kandaswamy Subramanian , Sarah Eftekharzadeh , Leslie Proudfit
|
| Journal Info |
IOP Publishing | The Astrophysical Journal , vol: 952
, iss: 1
, pages: 4 - 4
|
| Publication Date |
7/1/2023 |
| ISSN |
0004-637X |
Type |
article |
| Open Access |
gold
|
| DOI |
https://doi.org/10.3847/1538-4357/acd934 |
| Keywords |
Wide-Field Spectroscopy (Score: 0.463937)
|
