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