Planetary Systems : Comets & Asteroids
The evolution of the gas with time. The counts above the continuum were integrated along the entire 7
arcsec slit for various molecular emission fea- tures and normalized to the value for spectrum 66, the first spectrum obtained
after the impact. Some of these measures include multiple lines in a dominant band, but for C2 and C3, we measured a bandhead.
The error bars are the Poisson noise statistics and do not account for extinction uncertainties, diffi- culty removing the continuum,
etc. The different molecular species reacted on different timescales. Note that we saw no increase in molecular emission in the
first 10 minute spectrum after the impact so the value of 1 in this plot represents
the ambient cometary emission and the increase came after at least 10 minutes post-impact.
Observations of Comet 9P/Tempel 1 with the Keck 1 HIRES Instrument During Deep Impact