Kresimir TISANIC
(Department of Physics, Faculty of Science, University of Zagreb)
The shape of the spectral energy distribution (SED) of galaxies in the radio is known to be influenced by synchrotron and free-free emission. The average radio SED can be used to better calibrate the (F)IR-to-radio correlation, but SEDs in the radio are as of yet poorly constrained. Here we present a study of the radio spectral index of an SFR-complete sample of highly star-forming galaxies (SFR>100 Msol/yr) in the COSMOS field using the Survival analysis technique. We employ observations in the rest-frame frequency range from ~500 MHz to 15 GHz obtained by the GMRT and the (J)VLA telescopes. We further present previously unpublished data taken by the GMRT at observer-frame 325 and 610 MHz. We observe a flattening of the spectral index below 4 GHz compared to that above 4 GHz and discuss possible sources of the change in spectral shape.