ISO Status Report - May 2004
A new version of IDA (V7.0) has been released on 8 June. The major improvement consists in the enhacement of quality information. Every standard observation in the archive has a new product called "Data Quality Report", which compiles the whole quality information available. A more extended and refined list of flags has also been defined for a better characterization of the observations. Some more general caveats are described for each instrument mode.
ISO data were extensively used in the first science demonstration of the Astrophysical Virtual Observatory, held on 27 January at ESO, Garching.
A "mid-term" review of Active Archive Phase activities will be held on 14-15 June, with a Board - including data providers and data users - based upon that of the previous review.
Science Highlights
ISO continues to have a significant presence in the refereed literature. ISO papers cover all areas of astronomy. Recent results include:
- A molecular inventory of the Asymptotic Giant Branch star W Hya
Spectra obtained with the SWS and LWS spectrometers show evidence for the presence of amorphous silicates, aluminum oxide, and magnesium-iron oxide grains. The molecular absorption bands due to H2O, OH, CO, CO2, SiO, and SO2 lead to excitation temperatures for different bands which range from 300 to 3000 K. This is interpreted as originating from different gas layers. The three CO2 bands in the 15 micron region, resolved into individual Q-lines in emission by the SWS Fabry-Perot, allow the direct determination of the excitation temperature and column density of the emitting gas. This reveals the presence of a warm (~450 K) extended layer of CO2, somewhere between the photosphere and the dust formation zone.
- Extended molecular absorption, photodissociation, and photoionization around the Sagittarius B2 region.
Large scale observations obtained with the ISO LWS spectrometer, spanning an area of 9' x 27' (~25 x 70 pc) around Sgr B2 have been analysed. The spectra are dominated by the strong continuum emission of dust, the widespread molecular absorption of light hydrides (OH, CH, and H2O), and the fine-structure lines of [N II], [N III], [O III], [C II], and [O I]. The widespread dust emission is reproduced by a cold component (~13-22 K), together with a warm component (~24-38 K), representing ~10% of the dust opacity. The fine-structure line emission reveals a very extended component of ionized gas, with an average electron density of ~240 cm-3. More than 70 lines from 15 molecular and atomic species are observed at high signal-to-noise ratios with the LWS Fabry-Perot.