ISO Status Report - November 2006
In July, the contents of the archive were enriched with two new sets of Highly Processed Data Products (HPDP) - LWS Observations of Asteroids (a catalogue of 59 manually reduced observations of asteroids) and ISOPHOT C200 chopped observations of compact objects (a catalogue of 605 C200 ISOPHOT observations of 542 compact objects). Other HPDP's have been enhanced with browse products, similar to those produced by the pipeline output. They can be visualised with the dedicated IDA tools and with a Virtual Observatory tool.
ISO continues to have a significant presence in the refereed literature, with 1375 papers published to date. Recent highlights include publication of the first FIR high resolution spectral line survey in the Orion region, obtained with the LWS in Fabry-Perot mode.
The paper by Lerate et al. (MNRAS, 370, 597) discusses the Orion Kleinmann-Low (KL) cluster. A total of 152 lines are clearly detected and a further 34 features are tentatively identified. The spectrum is dominated by the molecular species H2O, OH and CO, along with [OI] and [CII] lines from PDR or shocked gas and [OIII], [NIII] lines from the foreground M42 HII region. Several isotopic species, as well as NH3, are also detected. HDO and H3O+ are tentatively detected for the first time in the far-infrared range towards Orion-KL.
The paper from Goicoechea et al. (ApJ, 641,49) discusses in particular 20 resolved OH rotational lines. Their profiles show a complex behaviour evolving from pure absorption, P Cygni type, to pure emission. A decrease of excitation outside the core of the cloud is revealed. Most of the excited OH arises from Orion outflow(s), that is, the "plateau" spectral component. Even with these conditions, the OH excitation is heavily coupled with the strong dust continuum emission from the inner "hot" core regions and from the expanding flow itself.