Roger Lynds
Tucson Nighttime Scientific Staff
Areas of Interest
Galaxy Evolution and Cosmology
Recent Research Results
Lynds has been engaged in two types of projects bearing on the subject
of star formation histories of galaxies. One approach has been to
study the photometric characteristics of galaxies revealed in long-
exposure images obtained with the Hubble Space Telescope. The aim is
to develop evidence of a higher incidence of star formation at great
distances and early epochs in the lifetime of the Universe. In
particular, are we beginning to see galaxies in their first phase of
star formation when we go to very early epochs? At the other end of
the distance scale, Lynds has been working on local galaxies dominated
by current star formation. The goal has been to determine whether or
not there are any galaxies at the current epoch which are undergoing
their very first phase of star formation. One galaxy, VII-Zw-403, a
very blue, dwarf galaxy, was originally thought to be an entirely new
galaxy. However, Hubble Space Telescope observations reveal that there
is a smoothly distributed, evolved population of stars in which the
star forming regions are embedded. Another galaxy, I-Zw-18, has seemed
to be an even more promising example of an entirely new galaxy. It is
somewhat more distant than VII-Zw-403 so that only the supergiants and
blue main sequence stars are resolved, but Lynds has found evidence
that there is a substructure of unresolved red stars which likely
represent the giant branch of an evolved population of stars. The
conclusion may very well be that, at the current epoch, star formation
only occurs within the gravitational potential wells of galaxies of
older stars.
Future Research Plans
Lynds's future research is expected to continue along much the same
lines. He hopes to develop evidence of a relationship between the
abundance of heavy elements in star-forming regions and the mass of
neutral hydrogen clouds in which the host galaxy may be embedded. One
might expect that if such hydrogen clouds are essentially primordial,
having few if any heavy elements, any stars formed from such material
would reflect that fact.
Service
Lynds has been an active member of the observatory Safety Committee and
is one of the instrument scientists for the 4-Meter Prime Focus CCD
Camera.
Go to: [ NOAO Scientific Staff ]
[ NOAO ]
[ CTIO ]
[ KPNO ]
[ NSO ]
[ USGP ]
NOAO is operated by the Association of U
niversities for Research in Astronomy
(AURA), Inc. under cooperative agreement with the
National Science Foundation
Posted: 06Dec1996