The following document lists the file abstract/JBERNARD_COLVAR_2.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
============================================================================ ==> In this proposal, more time is being requested for JBERNARD.COLORVAR ==> This proposal requests an upgrade from Priority 3 for JBERNARD.COLORVAR ============================================================================ We propose to investigate the nature of small dust particles in regions of the interstellar medium showing sharp changes of physical conditions such as radiation field, density or temperature. The selected targets (ursa and taufil) were originally in the spring list of JBERNARD.COLORVAR. We also request upgrade for some AOTs of this program. The observations will consist of one-dimensional rasters (cuts) with ISOCAM, PHOT and LWS across regions showing color gradients in the IRAS data (12 to 100 microns). The cuts will be observed in all IR features attributed to small dust particles and in the nearby continuum. The obtained data will extend the COLORVAR results to cirrus type clouds and dense filaments inside molecular clouds. The combination of filters will allow to separate the continuum and feature emission.It will be possible to study processes leading to the formation and destruction of small dust particles, as well as their relationship with the gas phase and dust surface chemistry. Possible triggering of small dust particles enhancement by shocks and the heating of the gas phase through photoelectric effect will also be investigated. Apart from evidencing abundance variations, these observations may provide information about other properties as size spectrum, dehydrogenation, ionization. This proposal complements the GTO program FBOULANG.SMALLPAR and LNORDH.SURVEY_1. It is less extenssive as far as sky coverage is concerned, but will give more detailed spectral information, which will be critical to understand the role played by small particles in the ISM chemistry.