Computer Science
Scientific paper
Apr 1987
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1987aipc..155....8g&link_type=abstract
AIP Conference Proceedings, Volume 155, pp. 8-18 (1987).
Computer Science
9
Infrared, Star Formation
Scientific paper
Dust obscures our view of the Galactic center, and complicates enormously the search for a ``central engine.'' One straightforward but indirect method is to study the thermal emission from dust in the nucleus. A very simplistic assumption, that the nucleus is choked with dust, leads to the prediction that a central engine, if present, will produce a single bright infrared source. Observations made more than a decade ago excluded this naive possibility. Instead, 10 μm images of the Galactic center are complicated, with multiple peaks in the emission.
Existing radio observations of Sgr A had already suggested the presence of ultraviolet radiation in the nucleus, and so it was that some workers saw the 10μm image as evidence for a burst of star formation. The demonstration of the existence of late type supergiants within the field of the 10μm map encouraged that interpretation.
The possibility that the dust density in the inner Galaxy is actually very low was not taken seriously until it was directly demonstrated by far infrared observations. These observations showed that a ring of neutral material encircles the nucleus at a radius of 2 parsecs, that within the central cavity of this ring the dust density is low, and that this inner region is transparent to optical and ultraviolet radiation; the structure observed at 10μm is located within the cavity in the ring.
Maps of the infrared color temperature distribution are symmetric and peak centrally in the vicinity of the nuclear source IRS16. There are no temperature peaks at the 10μm brightness peaks. The energetics of the inner few parsecs of the Galaxy are dominated by a strong source of luminosity resident at the Galactic center.
Wisps and streamers of material falling inward are exposed to the radiation field of the central object, which ionizes the gas and heats the dust. The clumpy density distribution is responsible for the complicated appearance of the 10μm map.
There is no direct or compelling evidence for star formation in the very center of the Galaxy. The appearance of the interstellar medium in the inner Galaxy is dictated by the presence of a nuclear source. We cannot presently tell if the nuclear source is powered by star formation or by some more exotic object, such as a black hole.
No associations
LandOfFree
Dust emission and the evidence for star formation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Dust emission and the evidence for star formation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dust emission and the evidence for star formation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1346958