Physical processes in the ISM

Radio-FIR correlation as a probe to interplay between star formation as ISM

23 Oct 2013, 09:00

5h

MPE

Poster Poster Session: Dependence of star formation on ISM properties (Poster 31-34)

Description

We investigate the correlation between the radio continuum and far-infrared (FIR) emission in the Fireworks galaxy NGC6946. The nonthermal radio-FIR correlation changes with both star formation and magnetic field strengths. The FIR-to-radio ratio is linearly correlated with the total magnetic field strength. This connection is self-consistent and independent from the star formation feedback. This is the first evidence of the importance of the magnetic fields in controlling the radio-FIR correlation in a galaxy. A scale-by-scale analysis of the radio-FIR correlation in NGC6946 and other nearby galaxies M31, M33, M51, and the LMC shows that the smallest scale on which the correlation holds changes with the degree of the regularity of the magnetic field and hence the propagation length of cosmic ray electrons. We further study the role of gas density and radiation field on the radio-FIR correlation in NGC6946.