VLA Colloquium Series:
28 September 1995
Alan Watson
New Mexico State University
Investigations of Dusty Nuclear Starburst Galaxies
Nuclear starburst galaxies, as might be expected, tend to be very
dusty, and this forces studies of their stellar content into the
near infrared. Unfortunately, their near infrared colours are
peculiar, being redder in H-K at a given J-H than would be
expected from the simplest model of extinction. For the last
decade, the standard explanation for this was excess emission in the
K band from very hot dust. I will present an alternative
explanation: that the peculiar colours are the result of a radiation
transfer effect arising from mixed optical depths to the stars.
This explanation arises naturally if nuclear starbursts consist of
densely packed compact clusters cloaked by dust. Recent high
resolution observation of the prototypical nuclear starburst galaxy
NGC 253 with HST and NTT favour this latter explanation, and seem to
rule out significant emission in K from hot dust. Finally, I will
briefly discuss the properties of the most extreme stellar cluster
in NGC 253 and show that it is the best present candidate for a
young globular cluster.
Thursday, 28 September 1995
11:00am
Array Operations Center Auditorium
Local Host: Michael Rupen
Other NRAO/Socorro colloquia
mrupen@nrao.edu