THE PANCHROMATIC STARBURST INTENSITY LIMIT AT LOW AND HIGH-REDSHIFT

The integrated bolometric effective surface brightness S-e distributio ns of starbursts are investigated for samples observed in (1) the rest frame ultraviolet (UV), (2) the far-infrared and H alpha, and (3) 21 cm radio continuum emission. For the UV sample we exploit a tight empi rical relationship between UV reddening and extinction to recover the bolometric flux. Parameterizing the S-e upper limit by the 90th percen tile of the distribution, we find a mean S-e9.0=2.0x10(11)L.kpc(-2) fo r the three samples, with a factor of 3 difference between the samples . This is consistent with what is expected from the calibration uncert ainties alone. We find little variation in S-e.90 with effective radii for R-e similar to 0.1 - 10 kpc, and little evolution out to redshift s approximate to 3. The lack of a strong dependence of S-e.90 on wavel ength, and its consistency with the pressure measured in strong galact ic winds, argue that it corresponds to a global star formation intensi ty limit ((Sigma) over dot(e.90)similar to 45 - M. kpc(-2)yr(-1)) rath er than being an opacity effect. There are several important implicati ons of these results: (1) There is a robust physical mechanism limitin g starburst intensity. We note that starbursts have S-e consistent wit h the expectations of gravitational instability models applied to the solid body rotation portion of galaxies. (2) Elliptical galaxies and s piral bulges can plausibly be built with maximum intensity bursts, whi le normal spiral disks cannot, (3) The UV extinction of high-z galaxie s is significant, implying that star formation in the early universe i s moderately obscured. After correcting for extinction, the observed m etal production rate at z similar to 3 agrees well with independent es timates made for the epoch of elliptical galaxy formation. (C) 1997 Am erican Astronomical Society.