The Nature of the H2 Emitting Gas in the Crab Nebula
Abstract
We use a combination of NASA ADP data and new ground-based observations to study the molecular cores located in the Crab nebula's filaments. Knot 51 is a spatially isolated knot of H2 for which we present long slit optical and NIR spectra covering emission lines from ionized, neutral, and molecular gas, as well as, HST and ground-based NIR narrow-band images. In a previous paper, we measured the H2 temperature of knot 51 to be 3000 K. We present plasma simulations of knot 51 to probe the excitation mechanisms, formation processes and dust content in environments which can produce the observed H2 emission. One interesting viable case has a core that is primarily atomic, with the H2 emission coming from just a trace molecular component. In this unusual situation, H2 forms primarily through associative detachment rather than through the normal grain cataylsis process.
- Publication:
-
American Astronomical Society Meeting Abstracts #220
- Pub Date:
- May 2012
- Bibcode:
- 2012AAS...22043112R