there is strong evidence of interstellar matter in the central regions of galactic globular clusters (ggcs) due to mass loss processes of population ii stars during the post ms stages of the stellar evolution. dust should be present in the most massive and concentrated clusters: ir excesses around luminous giants and long period variables and scattered polarized light have been detected in their central regions. recent 10 mum ground based imaging obtained by the proposers in a central field of omega centauri shows the presence of both compact and extended emission. besides, some clusters have an iras source in their core and the 12-25 mum color temperature (100<= t <=300) indicates the possible presence of a warm dust. iso offers a unique opportunity to investigate the physical and chemical properties of this intracluster matter. its photometric and polarimetric capabilities, with relatively large spatial resolution and field coverage and with very low thermal background in the 10 and 20 mum windows, allow one to make a deep survey of the distribution and chemical composition of the dust in the central region of ggcs. the resulting database would be valuable for ground-based observations with 8m class telescopes at higher spatial resolution but lower sensitivity. it would have at least 2 fundamental astrophysical implications: 1) studying the physics of mass loss in pop ii stellar systems of well known age and metallicity. this part of the program would be complementary to that one on field agb stars for which iso guaranteed time has already been scheduled; 2) studying the circumstellar medium inside a closed stellar system, its chemical evolution and dynamical interaction with the galaxy.
Instrument
CAM03 , PHT03
Temporal Coverage
1997-02-20T14:22:20Z/1997-08-07T05:03:49Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
