“Study of the ISM in our own Galaxy and the Dust Emission in Early-type Galaxies”
The purpose of this research is to use the large database of observations taken by the ISO satellite and data that will be soon available from SOFIA and SIRTF to study the ISM of our own and external galaxies. The project is split into two separate tasks : Study how PAHs respond to changes in UV illumination and how their emission spectrum changes in reflection nebulae; we will use clustering techniques applied to spectral-spatial data cubes to group regions with similar spectra. Clustering uncovers the underlying geometry of the nebula, and reduce the number of spectra from each object to a manageable number. We use the Ames Astrochemistry Laboratory PAH database to determine the ion to neutral ratio, and compare the results with theoretical calculation.
Detect and characterize the dust emission in early-type galaxies. We investigate and address the following scientific issues: 1) Map the distribution of the dust (warm and cold dust components) in and around early-type galaxies located in the field, groups and rich clusters. 2) Derive the physical properties of the dust, such as temperature and mass. 3) Determine how hot interstellar gas affects the size distribution of dust grains and their total mass.4) Investigate the proposition that dust is continuously formed and destroyed in cooling flows. 5) Test the hypothesis that some of the dust may have an external origin.
This program is comprised of observational and theoretical projects and the work is done in collaboration with observational and theoretical astronomers both at NASA Ames Research Center >and at the University of California Santa Cruz.