ar X iv : a st ro - p h / 03 11 02 2 v 1 3 N ov 2 00 3 High - Energy Radiation Probes of Protostellar Envelopes

We present observations of molecular high-energy radiation probes and report the first detections of CO + toward W3 IRS5, a source containing ultracom-pact HII regions. UV radiation and X-rays from the central objects may enhance molecules due to photodissociation and ionization processes. To study the effects on the immediate YSO environment, we are developing time-and depth-dependant chemical models containing UV and X-ray chemistry, by extending the models of Doty et al. (2002). Molecules like CO + or NO may be used as tracers of very early X-ray emission in regions of high extinction, from which no X-ray photons can be detected.