2003ApJ...597..274Y

Mrk 1039 and IRAS F08208+2816 are two new Wolf-Rayet galaxies whose optical spectroscopic observations suggest that star formation in these galaxies occurs in brief bursts for starburst ages of only ∼4x10⁶ yr. Other observational diagnostics are needed to measure the contributions of older and less massive stars to the total luminosity of Wolf-Rayet galaxies. Both far-infrared (FIR) and radio continuum emission provide such diagnostics for stars with masses as low as 5M_☉and lifetimes of several times 10⁷ yr. We observed these two Wolf-Rayet galaxies at 20, 6, and 2 cm wavelengths using the B, C, and D configurations of the VLA, respectively. Mrk 1039 contains a fairly small (d_r<500 pc), primarily thermal radio source whose FIR/radio flux ratio is consistent with the isolated H II region expected if the starburst in Mrk 1039 is really very young (τ∼4x10⁶ yr). In contrast, F08208+2816 has a nonthermal radio spectrum and obeys the FIR/radio correlation. These two radio properties indicate that the young Wolf-Rayet starburst in F08208+2816 is embedded in a large and luminous galaxy that has hosted comparably luminous starburst activity extending ≳3x10⁷ yr in the past.