On the Ongoing Multiple Blowout in NGC 604

Several facts regarding the structure of NGC 604 are examined here. The threemain cavities, produced by the mechanical energy from massive stars which inNGC 604 are spread over a volume of 10$^6$ pc$^3$, are shown here to beundergoing blowout into the halo of M33. High resolution long slit spectroscopyis used to track the impact from massive stars while HST archive data is usedto display the asymmetry of the nebula. NGC 604 is found to be a collection of photoionized filaments and sections ofshells in direct contact with the thermalized matter ejected by massive stars.The multiple blowout events presently drain the energy injected by massivestars and thus the densest photoionized gas is found almost at rest and isexpected to suffer a slow evolution.Comment: 15 pages (11 text), 4 figures. To be published in Ap