Physical processes in the ISM

The Radio Continuum - Far Infrared Relation in Dwarf Irregular Galaxies

Not scheduled

20m

MPE

contributed talk

Speaker

Ged Kitchener (Centre for Astrophysics Research, University of Hertfordshire)

Description

We present a 6-cm radio continuum (RC) survey with the JVLA in C-configuration of the LITTLE THINGS sample of 39 local, gas-rich dwarf galaxies, and explore the radio continuum - Far Infrared (RC-FIR) relation in such systems. We generate images with a resolution of 3? and an rms noise of ~5muJy/beam, and detect significant emission in about half of our sample. We double the luminosity range sampled by previous authors to 8 dex, finding that the RC-FIR relation deviates from its linearity at a luminosity of about 1e19 W/Hz (6 GHz) or 1e22 W/Hz (70mu). We interpret this as low-mass, low-metalicity galaxies being under-luminous in the FIR (for a given SFR). We separate the thermal and non-thermal components of the RC on a spatially resolved basis using ancillary Halpha data, and find a large variation in galaxy-wide thermal fractions.